Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]	0000934612 (http://www.sec.gov/CIK)
Defined Benefit Plans and Other Postretirement Benefit Plans [Axis]	Defined Benefit Plans and Other Postretirement Benefit Plans [Domain]

Defined Benefit Plan Disclosure [Line Items]	Period [Axis]
	2016-01-01 - 2016-12-31
Schedule of Net Benefit Costs	Components of the net (benefit) cost for certain employee benefit plans were as follows (in millions):     Pension Benefits     Year Ended   Year Ended   Year Ended     December 31, 2016   December 31, 2015   December 31, 2014 Service cost   $ 46   $ 48   $ 38 Interest cost   95   90   95 Expected return on plan assets   (142 )   (138 )   (134 ) Amortization of prior service credits   (1 )   (1 )   (1 ) Amortization of net loss   1   2   1 Settlements   (1 )   (1 )   (1 )       Net (benefit) cost recognized   $ (2 )   $ —   $ (2 )     Retiree Health and Welfare Benefits     Year Ended   Year Ended   Year Ended     December 31, 2016   December 31, 2015   December 31, 2014 Service cost   $ 1   $ 1   $ 1 Interest cost   10   10   11 Amortization of prior service credits   (2 )   (2 )   (2 ) Amortization of net loss   1   2   1       Net cost recognized   $ 10   $ 11   $ 11
Schedule of Net Funded Status [Table Text Block]	The following table shows the change in projected benefit obligation (in millions):     Pension Benefits Change in Benefit Obligation   December 31, 2016   December 31, 2015 Projected benefit obligation at beginning of period   $ 2,320   $ 2,452 Service cost   46   48 Interest cost   95   90 Actuarial gain   (55 )   (111 ) Benefits paid   (143 )   (145 ) Administrative expenses   —   (1 ) Settlements   (16 )   (13 )    Projected benefit obligation at end of period   2,247   2,320    Component representing future salary increases   (102 )   (146 )       Accumulated benefit obligation at end of period   $ 2,145   $ 2,174     Retiree Health and Welfare Benefits Change in Benefit Obligation   December 31, 2016   December 31, 2015 Projected benefit obligation at beginning of period   $ 258   $ 280 Service cost   1   1 Interest cost   10   10 Plan participants’ contributions   5   5 Actuarial gain   (13 )   (13 ) Benefits paid   (24 )   (25 )       Projected benefit obligation at end of period   $ 237   $ 258 At December 31, 2016, BNSF’s pension plans had plan assets in excess of accumulated and projected benefit obligations. At December 31, 2015, BNSF's pension plans had plan assets in excess of accumulated benefit obligations and projected benefit obligations in excess of plan assets. The following tables show the change in plan assets of the plans (in millions):     Pension Benefits Change in Plan Assets   December 31, 2016   December 31, 2015 Fair value of plan assets at beginning of period   $ 2,289   $ 2,342 Actual return on plan assets   193   95 Employer contributionsa   10   11 Benefits paid   (143 )   (145 ) Administrative expenses   —   (1 ) Settlements   (16 )   (13 )       Fair value of plan assets at measurement date   $ 2,333   $ 2,289 a  Employer contributions were classified as Other, Net under Operating Activities in the Company’s Consolidated Statements of Cash Flows.     Retiree Health and Welfare Benefits Change in Plan Assets   December 31, 2016   December 31, 2015 Fair value of plan assets at beginning of period   $ —   $ — Employer contributionsa   19   20 Plan participants’ contributions   5   5 Benefits paid   (24 )   (25 )       Fair value of plan assets at measurement date   $ —   $ — a  Employer contributions were classified as Other, Net under Operating Activities in the Company’s Consolidated Statements of Cash Flows.   The following table shows the funded status, defined as plan assets less the projected benefit obligation (in millions):     Pension Benefits   Retiree Health and Welfare Benefits     December 31, 2016   December 31, 2015   December 31, 2016   December 31, 2015 Funded status (plan assets less projected benefit obligations)   $ 86   $ (31 )   $ (237 )   $ (258 )
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	The following table shows the pre-tax change in AOCI attributable to the components of the net cost and the change in benefit obligation (in millions):     Pension Benefits     Year Ended   Year Ended   Year Ended Change in AOCI   December 31, 2016   December 31, 2015   December 31, 2014 Beginning balance   $ 102   $ 34   $ 427 Amortization of net loss   1   2   1 Amortization of prior service credits   (1 )   (1 )   (1 ) Actuarial gain (loss)   106   68   (392 ) Settlements   (1 )   (1 )   (1 )       Ending balance   $ 207   $ 102   $ 34     Retiree Health and Welfare Benefits     Year Ended   Year Ended   Year Ended Change in AOCI   December 31, 2016   December 31, 2015   December 31, 2014 Beginning balance   $ (21 )   $ (34 )   $ (20 ) Amortization of net loss   1   2   1 Amortization of prior service credits   (2 )   (2 )   (2 ) Actuarial gain (loss)   13   13   (13 )       Ending balance   $ (9 )   $ (21 )   $ (34 )
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Pre-tax amounts currently recognized in AOCI consist of the following (in millions):     Pension Benefits   Retiree Health and Welfare Benefits     2016   2015   2016   2015 Net gain (loss)   $ 206   $ 99   $ (14 )   $ (28 ) Prior service credits   4   5   5   7 Settlements   (3 )   (2 )   —   — Pre-tax amount recognized in AOCI at December 31,   $ 207   $ 102   $ (9 )   $ (21 ) After-tax amount recognized in AOCI at December 31,   $ 128   $ 63   $ (6 )   $ (13 )
Schedule of Assumptions Used [Table Text Block]	The assumptions used in accounting for the BNSF plans were as follows:     Pension Benefits     Year Ended   Year Ended   Year Ended Assumptions Used to Determine Net Cost   December 31, 2016   December 31, 2015   December 31, 2014 Discount rate   4.2 %   3.8 %   4.5 % Expected long-term rate of return on plan assets   6.6 %   6.6 %   6.8 % Rate of compensation increase   3.8 %   3.8 %   3.8 %     Retiree Health and Welfare Benefits     Year Ended   Year Ended   Year Ended Assumptions Used to Determine Net Cost   December 31, 2016   December 31, 2015   December 31, 2014 Discount rate   4.1 %   3.7 %   4.5 % Rate of compensation increase   3.8 %   3.8 %   3.8 %       Pension Benefits   Retiree Health and Welfare Benefits Assumptions Used to Determine Benefit Obligations   December 31, 2016   December 31, 2015   December 31, 2016   December 31, 2015 Discount rate   4.1 %   4.2 %   3.9 %   4.1 % Rate of compensation increase   3.3 %   3.8 %   3.3 %   3.8 %
Sensitivity analysis of impact on future net benefit cost resulting from hypothetical change in assumptions [Text Block]	The following table is an estimate of the impact on future net benefit cost that could result from hypothetical changes to the most sensitive assumptions, the discount rate and rate of return on plan assets: Sensitivity Analysis     Change in Net Benefit Cost Hypothetical Discount Rate Change   Pension Retiree Health and Welfare 50 basis point decrease   $ 1  million increase   $ — decrease 50 basis point increase   $ 7  million decrease   $ — increase Hypothetical Rate of Return on Plan Assets Change   Pension         50 basis point decrease   $ 11  million increase         50 basis point increase   $ 11  million decrease
Schedule of Health Care Cost Trend Rates [Table Text Block]	The following table presents assumed health care cost trend rates:     Year Ended   Year Ended   Year Ended     December 31, 2016   December 31, 2015   December 31, 2014 Assumed health care cost trend rate for next year (participants over 65)   3.0 %   3.0 %   3.0 % Assumed health care cost trend rate for next year (participants under 65)   7.4 %   7.7 %   7.9 % Rate to which health care cost trend rate for participants under 65 is expected to decline and remain   4.4 %   4.5 %   4.5 % Year that the rate reaches the ultimate trend rate   2039   2038   2028
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]	A one percentage point change in assumed health care cost trend rates would have the following effects (in millions):     One Percentage- Point Increase   One Percentage- Point Decrease Effect on total service and interest cost   $ 1   $ (1 ) Effect on postretirement benefit obligation   $ 17   $ (15 )
Schedule of Allocation of Plan Assets [Table Text Block]	The following table summarizes the investments of BNSF’s funded pension plans as of December 31, 2016, based on the inputs used to value them (in millions):     Total as of             Asset Category   December 31, 2016   Level 1 Inputs a   Level 2 Inputs a   Level 3 Inputs a Cash and equivalents   $ 1   $ 1   $ —   $ — Equity securitiesb   2,139   2,139   —   — Government obligations   164   —   164   — Other fixed maturity securities   21   —   21   — Investment funds and other   8   8   —   — Totalc   $ 2,333   $ 2,148   $ 185   $ — a See Note 2 to the Consolidated Financial Statements under the heading “Fair Value Measurements” for a definition of each of these levels of inputs. b As of December 31, 2016, four equity securities each exceeded 10 percent of total plan assets.  These investments represent approximately 56 percent of total plan assets. c Excludes less than $1 million accrued for dividend and interest receivable. Comparative Prior Year Information The following table summarizes the investments of BNSF’s funded pension plans as of December 31, 2015, based on the inputs used to value them (in millions):     Total as of             Asset Category   December 31, 2015   Level 1 Inputs a   Level 2 Inputs a   Level 3 Inputs a Cash and equivalents   $ 167   $ 3   $ 164   $ — Equity securitiesb   2,060   2,060   —   — Government obligations   12   —   12   — Other fixed maturity securities   31   —   31   — Investment funds and other   19   19   —   — Total c   $ 2,289   $ 2,082   $ 207   $ — a See Note 2 to the Consolidated Financial Statements under the heading “Fair Value Measurements” for a definition of each of these levels of inputs. b As of December 31, 2015, three equity securities each exceeded 10 percent of total plan assets.  These investments represented approximately 47 percent of total plan assets. c Excludes less than $1 million accrued for dividend and interest receivable.
Schedule of Expected Benefit Payments Years 2015 - 2024 [Table Text Block]	The following table shows expected benefit payments from its defined benefit pension plans and expected claim payments for the retiree health and welfare plan for the next five fiscal years and the aggregate five years thereafter (in millions): Fiscal year   Expected Pension Plan Benefit Payments a  Expected Retiree Health and Welfare Payments 2017   $ 166   $ 19 2018   $ 153   $ 18 2019   $ 152   $ 18 2020   $ 151   $ 17 2021   $ 145   $ 16 2022-2026   $ 661   $ 73 a Primarily consists of the BNSF Retirement Plan payments, which are made from the plan trust and do not represent an immediate cash outflow to the Company.