| Compensation and Retirement Disclosure [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
|---|
Compensation and Retirement Disclosure [Abstract] | |
Schedule of Net Funded Status [Table Text Block] | Obligations and funded status The funded status of the pension and other postretirement benefit plans at December 31, 2016 and 2015 was as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | | 2016 | | | 2015 | | | 2016 | | | 2015 | | | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| (in millions of U.S. dollars) | | | | | | | Benefit obligation, beginning of year | $ | 10 |
| | $ | 559 |
| | $ | 10 |
| | $ | 584 |
| | $ | 16 |
| | $ | — |
| | $ | 16 |
| | $ | — |
| Acquisition of Chubb Corp | 3,153 |
| | 372 |
| | — |
| | — |
| | 491 |
| | 15 |
| | — |
| | — |
| Service cost | 75 |
| | 18 |
| | — |
| | 6 |
| | 9 |
| | 1 |
| | 1 |
| | — |
| Interest cost | 103 |
| | 30 |
| | — |
| | 21 |
| | 16 |
| | 1 |
| | — |
| | — |
| Actuarial loss | 131 |
| | 204 |
| | — |
| | 13 |
| | 33 |
| | 3 |
| | (1 | ) | | — |
| Benefits paid | (79 | ) | | (22 | ) | | — |
| | (22 | ) | | (11 | ) | | — |
| | — |
| | — |
| Amendments | — |
| | (9 | ) | | — |
| | 1 |
| | (410 | ) | | — |
| | — |
| | — |
| Curtailments | (259 | ) | | (7 | ) | | — |
| | — |
| | — |
| | — |
| | — |
| | — |
| Settlements | (99 | ) | | (7 | ) | | — |
| | (7 | ) | | — |
| | — |
| | — |
| | — |
| Foreign currency revaluation | — |
| | (113 | ) | | — |
| | (37 | ) | | — |
| | 1 |
| | — |
| | — |
| Benefit obligation, end of year | $ | 3,035 |
| | $ | 1,025 |
| | $ | 10 |
| | $ | 559 |
| | $ | 144 |
| | $ | 21 |
| | $ | 16 |
| | $ | — |
| Plan assets at fair value, beginning of year | $ | 9 |
| | $ | 564 |
| | $ | 9 |
| | $ | 579 |
| | $ | — |
| | $ | — |
| | $ | — |
| | $ | — |
| Acquisition of Chubb Corp | 2,473 |
| | 315 |
| | — |
| | — |
| | 138 |
| | — |
| | — |
| | — |
| Actual return on plan assets | 359 |
| | 168 |
| | — |
| | 40 |
| | 29 |
| | — |
| | — |
| | — |
| Employer contributions | 98 |
| | 67 |
| | — |
| | 10 |
| | 3 |
| | — |
| | — |
| | — |
| Benefits paid | (79 | ) | | (22 | ) | | — |
| | (22 | ) | | (11 | ) | | — |
| | — |
| | — |
| Settlements | (95 | ) | | (7 | ) | | — |
| | (7 | ) | | — |
| | — |
| | — |
| | — |
| Foreign currency revaluation | — |
| | (123 | ) | | — |
| | (36 | ) | | — |
| | — |
| | — |
| | — |
| Plan assets at fair value, end of year | $ | 2,765 |
| | $ | 962 |
| | $ | 9 |
| | $ | 564 |
| | $ | 159 |
| | $ | — |
| | $ | — |
| | $ | — |
| Funded status at end of year | $ | (270 | ) | | $ | (63 | ) | | $ | (1 | ) | | $ | 5 |
| | $ | 15 |
| | $ | (21 | ) | | $ | (16 | ) | | $ | — |
|
|
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] | Net actuarial loss (gain) and prior service cost included in AOCI that were not yet recognized as components of net benefit costs in Net income at December 31, 2016 and 2015 were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | | 2016 | | | 2015 | | | 2016 | | | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| (in millions of U.S. dollars) | | | | | Net actuarial loss (gain) | $ | (207 | ) | | $ | 156 |
| | $ | — |
| | $ | 107 |
| | $ | 14 |
| | $ | 3 |
| Prior service cost | — |
| | (2 | ) | | — |
| | 7 |
| | (395 | ) | | — |
| Total | $ | (207 | ) | | $ | 154 |
| | $ | — |
| | $ | 114 |
| | $ | (381 | ) | | $ | 3 |
|
|
Schedule of Assumptions Used [Table Text Block] | The weighted-average assumptions used to determine the projected benefit obligation were as follows: | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| | | | | December 31, 2016 | | | | | | | | Discount rate | 4.14 | % | | 2.83 | % | | 2.86 | % | | 3.73 | % | Rate of compensation increase | 4.00 | % | | 3.57 | % | | N/A |
| | N/A |
| December 31, 2015 | | | | | | | | Discount rate | NM |
| | 3.61 | % | | NM |
| | | Rate of compensation increase | NM |
| | 3.05 | % | | NM |
| | | NM – not meaningful | | | | | | | |
The components of net pension and other postretirement benefit costs reflected in Net income and other changes in plan assets and benefit obligations recognized in other comprehensive income were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | Year Ended December 31, 2016 | U.S. Plans |
| | Non-U.S. Plans |
| | Total |
| | U.S. Plans |
| | Non-U.S. Plans |
| | Total |
| (in millions of U.S. dollars) | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | 75 |
| | $ | 18 |
| | $ | 93 |
| | $ | 9 |
| | $ | 1 |
| | $ | 10 |
| Interest cost | 103 |
| | 30 |
| | 133 |
| | 16 |
| | 1 |
| | 17 |
| Expected return on plan assets | (165 | ) | | (39 | ) | | (204 | ) | | (8 | ) | | — |
| | (8 | ) | Amortization of net actuarial loss (gain) | — |
| | 2 |
| | 2 |
| | (1 | ) | | — |
| | (1 | ) | Amortization of prior service cost | — |
| | (1 | ) | | (1 | ) | | (15 | ) | | — |
| | (15 | ) | Curtailments | (117 | ) | | — |
| | (117 | ) | | — |
| | — |
| | — |
| Settlements | (2 | ) | | 1 |
| | (1 | ) | | — |
| | — |
| | — |
| Net periodic (benefit) cost | $ | (106 | ) | | $ | 11 |
| | $ | (95 | ) | | $ | 1 |
| | $ | 2 |
| | $ | 3 |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | (326 | ) | | $ | 49 |
| | $ | (277 | ) | | $ | 14 |
| | $ | 3 |
| | $ | 17 |
| Prior service benefit | — |
| | (8 | ) | | (8 | ) | | (395 | ) | | — |
| | (395 | ) | Curtailments | 117 |
| | — |
| | 117 |
| | — |
| | — |
| | — |
| Settlements | 2 |
| | (1 | ) | | 1 |
| | — |
| | — |
| | — |
| Total (increase) decrease in other comprehensive income | $ | (207 | ) | | $ | 40 |
| | $ | (167 | ) | | $ | (381 | ) | | $ | 3 |
| | $ | (378 | ) | Year Ended December 31, 2015 | | | | | | | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | — |
| | $ | 6 |
| | $ | 6 |
| | $ | 1 |
| | $ | — |
| | $ | 1 |
| Interest cost | — |
| | 21 |
| | 21 |
| | — |
| | — |
| | — |
| Expected return on plan assets | — |
| | (29 | ) | | (29 | ) | | — |
| | — |
| | — |
| Amortization of net actuarial loss | — |
| | 2 |
| | 2 |
| | (1 | ) | | — |
| | (1 | ) | Settlements | — |
| | 1 |
| | 1 |
| | — |
| | — |
| | — |
| Net periodic benefit cost | $ | — |
| | $ | 1 |
| | $ | 1 |
| | $ | — |
| | $ | — |
| | $ | — |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | — |
| | $ | (16 | ) | | $ | (16 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Prior service cost | — |
| | 1 |
| | 1 |
| | — |
| | — |
| | — |
| Total increase in other comprehensive income | $ | — |
| | $ | (15 | ) | | $ | (15 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Year Ended December 31, 2014 | | | | | | | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | — |
| | $ | 6 |
| | $ | 6 |
| | $ | 1 |
| | $ | — |
| | $ | 1 |
| Interest cost | — |
| | 25 |
| | 25 |
| | — |
| | — |
| | — |
| Expected return on plan assets | — |
| | (30 | ) | | (30 | ) | | — |
| | — |
| | — |
| Amortization of net actuarial loss | — |
| | 2 |
| | 2 |
| | 1 |
| | — |
| | 1 |
| Net periodic benefit cost | $ | — |
| | $ | 3 |
| | $ | 3 |
| | $ | 2 |
| | $ | — |
| | $ | 2 |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | — |
| | $ | (10 | ) | | $ | (10 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Prior service cost | — |
| | 8 |
| | 8 |
| | — |
| | — |
| | — |
| Total increase in other comprehensive income | $ | — |
| | $ | (2 | ) | | $ | (2 | ) | | $ | — |
| | $ | — |
| | $ | — |
|
The estimated net actuarial loss that will be amortized from AOCI into net periodic benefit costs in Net income for Non-U.S. pension plans during 2017 is $3 million. The estimated net prior service credit that will be amortized from AOCI into net periodic benefit costs in Net income during 2017 for U.S. other postretirement benefit plans is $92 million.
The weighted-average assumptions used to determine the net periodic pension and other postretirement benefit costs were as follows: | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | | U.S. Plans |
| | Non-U.S. Plans |
| | U.S. Plans |
| | Non-U.S. Plans |
| Year Ended December 31 | | | | 2016 | | | | | | | | Discount rate in effect for determining service cost | 4.38 | % | | 3.85 | % | | 4.56 | % | | 4.30 | % | Discount rate in effect for determining interest cost | 3.59 | % | | 3.44 | % | | 3.82 | % | | 4.30 | % | Rate of compensation increase | 4.00 | % | | 3.33 | % | | N/A |
| | N/A |
| Expected long-term rate of return on plan assets | 7.00 | % | | 4.79 | % | | 6.34 | % | | N/A |
| 2015 | | | | | | | | Discount rate | NM |
| | 3.51 | % | | NM |
| | | Rate of compensation increase | NM |
| | 3.09 | % | | NM |
| | | Expected long-term rate of return on plan assets | NM |
| | 4.81 | % | | NM |
| | | 2014 | | | | | | | | Discount rate | NM |
| | 4.21 | % | | NM |
| | | Rate of compensation increase | NM |
| | 3.43 | % | | NM |
| | | Expected long-term rate of return on plan assets | NM |
| | 5.34 | % | | NM |
| | | NM – not meaningful | | | | | | | |
|
Schedule of Net Benefit Costs [Table Text Block] | The components of net pension and other postretirement benefit costs reflected in Net income and other changes in plan assets and benefit obligations recognized in other comprehensive income were as follows: | | | | | | | | | | | | | | | | | | | | | | | | | | Pension Benefits | | | Other Postretirement Benefits | | Year Ended December 31, 2016 | U.S. Plans |
| | Non-U.S. Plans |
| | Total |
| | U.S. Plans |
| | Non-U.S. Plans |
| | Total |
| (in millions of U.S. dollars) | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | 75 |
| | $ | 18 |
| | $ | 93 |
| | $ | 9 |
| | $ | 1 |
| | $ | 10 |
| Interest cost | 103 |
| | 30 |
| | 133 |
| | 16 |
| | 1 |
| | 17 |
| Expected return on plan assets | (165 | ) | | (39 | ) | | (204 | ) | | (8 | ) | | — |
| | (8 | ) | Amortization of net actuarial loss (gain) | — |
| | 2 |
| | 2 |
| | (1 | ) | | — |
| | (1 | ) | Amortization of prior service cost | — |
| | (1 | ) | | (1 | ) | | (15 | ) | | — |
| | (15 | ) | Curtailments | (117 | ) | | — |
| | (117 | ) | | — |
| | — |
| | — |
| Settlements | (2 | ) | | 1 |
| | (1 | ) | | — |
| | — |
| | — |
| Net periodic (benefit) cost | $ | (106 | ) | | $ | 11 |
| | $ | (95 | ) | | $ | 1 |
| | $ | 2 |
| | $ | 3 |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | (326 | ) | | $ | 49 |
| | $ | (277 | ) | | $ | 14 |
| | $ | 3 |
| | $ | 17 |
| Prior service benefit | — |
| | (8 | ) | | (8 | ) | | (395 | ) | | — |
| | (395 | ) | Curtailments | 117 |
| | — |
| | 117 |
| | — |
| | — |
| | — |
| Settlements | 2 |
| | (1 | ) | | 1 |
| | — |
| | — |
| | — |
| Total (increase) decrease in other comprehensive income | $ | (207 | ) | | $ | 40 |
| | $ | (167 | ) | | $ | (381 | ) | | $ | 3 |
| | $ | (378 | ) | Year Ended December 31, 2015 | | | | | | | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | — |
| | $ | 6 |
| | $ | 6 |
| | $ | 1 |
| | $ | — |
| | $ | 1 |
| Interest cost | — |
| | 21 |
| | 21 |
| | — |
| | — |
| | — |
| Expected return on plan assets | — |
| | (29 | ) | | (29 | ) | | — |
| | — |
| | — |
| Amortization of net actuarial loss | — |
| | 2 |
| | 2 |
| | (1 | ) | | — |
| | (1 | ) | Settlements | — |
| | 1 |
| | 1 |
| | — |
| | — |
| | — |
| Net periodic benefit cost | $ | — |
| | $ | 1 |
| | $ | 1 |
| | $ | — |
| | $ | — |
| | $ | — |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | — |
| | $ | (16 | ) | | $ | (16 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Prior service cost | — |
| | 1 |
| | 1 |
| | — |
| | — |
| | — |
| Total increase in other comprehensive income | $ | — |
| | $ | (15 | ) | | $ | (15 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Year Ended December 31, 2014 | | | | | | | | | | | | Costs reflected in Net income: | | | | | | | | | | | | Service cost | $ | — |
| | $ | 6 |
| | $ | 6 |
| | $ | 1 |
| | $ | — |
| | $ | 1 |
| Interest cost | — |
| | 25 |
| | 25 |
| | — |
| | — |
| | — |
| Expected return on plan assets | — |
| | (30 | ) | | (30 | ) | | — |
| | — |
| | — |
| Amortization of net actuarial loss | — |
| | 2 |
| | 2 |
| | 1 |
| | — |
| | 1 |
| Net periodic benefit cost | $ | — |
| | $ | 3 |
| | $ | 3 |
| | $ | 2 |
| | $ | — |
| | $ | 2 |
| Changes in plan assets and benefit obligations recognized in other comprehensive income | | | | | | | | | | | | Net actuarial loss (gain) | $ | — |
| | $ | (10 | ) | | $ | (10 | ) | | $ | — |
| | $ | — |
| | $ | — |
| Prior service cost | — |
| | 8 |
| | 8 |
| | — |
| | — |
| | — |
| Total increase in other comprehensive income | $ | — |
| | $ | (2 | ) | | $ | (2 | ) | | $ | — |
| | $ | — |
| | $ | — |
|
|
Schedule of Health Care Cost Trend Rates [Table Text Block] | The weighted average healthcare cost trend rate assumptions used to measure the expected cost of healthcare benefits were as follows: | | | | | | | | | | | | | | U.S. Plans | | | Non-U.S. Plans |
| | 2016 |
| | 2015 |
| | 2014 |
| | 2016 |
| Healthcare cost trend rate | 7.28 | % | | 6.50 | % | | 6.50 | % | | 6.61 | % | Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) | 4.50 | % | | 4.50 | % | | 4.50 | % | | 4.50 | % | Year that the rate reaches the ultimate trend rate | 2038 |
| | 2026 |
| | 2026 |
| | 2029 |
|
|
Schedule of Allocation of Plan Assets [Table Text Block] | The following table presents the fair values of the pension plan assets, by valuation hierarchy. For additional information on how we classify these assets within the valuation hierarchy, refer to Note 4 to the Consolidated financial statements. | | | | | | | | | | | | | | | | | December 31, 2016 | Pension Benefits | | (in millions of U.S. dollars) | Level 1 |
| | Level 2 |
| | Level 3 |
| | Total |
| U.S. Plans | | | | | | | | Short-term investments | $ | — |
| | $ | 43 |
| | $ | — |
| | $ | 43 |
| U.S. Treasury and agency | 206 |
| | 112 |
| | — |
| | 318 |
| Foreign and corporate bonds | — |
| | 482 |
| | 5 |
| | 487 |
| Equity securities | 728 |
| | — |
| | — |
| | 728 |
| Derivative instruments | 3 |
| | — |
| | — |
| | 3 |
| Total U.S. Plan assets (1) | $ | 937 |
| | $ | 637 |
| | $ | 5 |
| | $ | 1,579 |
| Non-U.S. Plans | | | | | | | | Short-term investments | $ | 2 |
| | $ | — |
| | $ | — |
| | $ | 2 |
| Foreign and corporate bonds | — |
| | 435 |
| | — |
| | 435 |
| Equity securities | 100 |
| | 412 |
| | — |
| | 512 |
| Total Non-U.S. Plan assets (1) | $ | 102 |
| | $ | 847 |
| | $ | — |
| | $ | 949 |
|
| | (1) | Excluded from the table above are $1.2 billion and $13 million of investments measured using NAV as a practical expedient |
|
Schedule of expected future benefit payments | Expected future payments are as follows: | | | | | | | | | For the years ending December 31 | U.S. Plans |
| | Non-U.S. Plans |
| (in millions of U.S. dollars) | | 2017 | $ | 132 |
| | $ | 20 |
| 2018 | 143 |
| | 23 |
| 2019 | 158 |
| | 25 |
| 2020 | 167 |
| | 26 |
| 2021 | 177 |
| | 27 |
| 2022–2026 | 931 |
| | 147 |
|
|