Movements in net defined benefit liability (asset) were as follows:
| Present value of the defined benefit obligation | Fair value of the plan assets | Net defined benefit liability (asset) | ||||||||||
| NT$ | NT$ | NT$ | ||||||||||
| Balance at January 1, 2015 | $ | 7,674,293 | $ | (3,502,487 | ) | $ | 4,171,806 | |||||
| Service cost | ||||||||||||
| Current service cost | 335,655 | - | $ | 335,655 | ||||||||
| Net interest expense (income) | 183,889 | (108,356 | ) | 75,533 | ||||||||
| Recognized in profit or loss | 519,544 | (108,356 | ) | 411,188 | ||||||||
| Remeasurement | ||||||||||||
| Return on plan assets (excluding amounts included in net interest) | - | 12,426 | 12,426 | |||||||||
| Actuarial loss arising from changes in financial assumptions | 309,695 | - | 309,695 | |||||||||
| Actuarial gain arising from experience adjustments | (243,363 | ) | - | (243,363 | ) | |||||||
| Actuarial gain arising from changes in demographic assumptions | (15,847 | ) | - | (15,847 | ) | |||||||
| Recognized in other comprehensive income | 50,485 | 12,426 | 62,911 | |||||||||
| Contributions from the employer | - | (611,581 | ) | (611,581 | ) | |||||||
| Benefits paid from the pension fund | (192,928 | ) | 192,928 | - | ||||||||
| Benefits paid from the Group | (43,088 | ) | - | (43,088 | ) | |||||||
| Exchange differences on foreign plans | (34,630 | ) | 43,341 | 8,711 | ||||||||
| Balance at December 31, 2015 | 7,973,676 | (3,973,729 | ) | 3,999,947 | ||||||||
| Service cost | ||||||||||||
| Current service cost | 329,838 | - | 329,838 | |||||||||
| Net interest expense (income) | 167,111 | (109,080 | ) | 58,031 | ||||||||
| Recognized in profit or loss | 496,949 | (109,080 | ) | 387,869 | ||||||||
| Remeasurement | ||||||||||||
| Return on plan assets (excluding amounts included in net interest) | - | 54,549 | 54,549 | |||||||||
| Actuarial loss arising from changes in financial assumptions | 156,193 | - | 156,193 | |||||||||
| Actuarial loss arising from experience adjustments | 200,723 | - | 200,723 | |||||||||
| Actuarial loss arising from changes in demographic assumptions | 5,716 | - | 5,716 | |||||||||
| Recognized in other comprehensive income | 362,632 | 54,549 | 417,181 | |||||||||
| Contributions from the employer | - | (807,232 | ) | (807,232 | ) | |||||||
| Benefits paid from the pension fund | (308,471 | ) | 308,471 | - | ||||||||
| Benefits paid from the Group | (36,033 | ) | - | (36,033 | ) | |||||||
(Continued)
| Present value of the defined benefit obligation | Fair value of the plan assets | Net defined benefit liability (asset) | ||||||||||
| NT$ | NT$ | NT$ | ||||||||||
| Liabilities assumed in a business combination | $ | 535 | $ | (535 | ) | $ | - | |||||
| Exchange differences on foreign plans | (99,404 | ) | 110,189 | 10,785 | ||||||||
| Balance at December 31, 2016 | 8,389,884 | (4,417,367 | ) | 3,972,517 | ||||||||
| Service cost | ||||||||||||
| Current service cost | 278,412 | - | 278,412 | |||||||||
| Past service cost and gain on settlements | (68,979 | ) | - | (68,979 | ) | |||||||
| Net interest expense (income) | 157,404 | (103,741 | ) | 53,663 | ||||||||
| Recognized in profit or loss | 366,837 | (103,741 | ) | 263,096 | ||||||||
| Remeasurement | ||||||||||||
| Return on plan assets (excluding amounts included in net interest) | - | 52,124 | 52,124 | |||||||||
| Actuarial loss arising from changes in financial assumptions | 56,860 | - | 56,860 | |||||||||
| Actuarial gain arising from experience adjustments | (315,090 | ) | - | (315,090 | ) | |||||||
(Continued)
| Present value of the defined benefit obligation | Fair value of the plan assets | Net defined benefit liability (asset) | ||||||||||
| NT$ | NT$ | NT$ | ||||||||||
| Actuarial loss arising from changes in demographic assumptions | $ | 762 | $ | - | $ | 762 | ||||||
| Recognized in other comprehensive income | (257,468 | ) | 52,124 | (205,344 | ) | |||||||
| Contributions from the employer | - | (484,790 | ) | (484,790 | ) | |||||||
| Benefits paid from the pension fund | (690,830 | ) | 690,830 | - | ||||||||
| Benefits paid from the Group | (96,575 | ) | - | (96,575 | ) | |||||||
| Exchange differences on foreign plans | 198,790 | (78,429 | ) | 120,361 | ||||||||
| Balance at December 31, 2017 | $ | 7,910,638 | $ | (4,341,373 | ) | $ | 3,569,265 | |||||
(Concluded)
| Present value of the defined benefit obligation | Fair value of the plan assets | Net defined benefit liability (asset) | ||||||||||
| US$ (Note 4) | US$ (Note 4) | US$ (Note 4) | ||||||||||
| Balance at January 1, 2017 | $ | 283,060 | $ | (149,034 | ) | $ | 134,026 | |||||
| Service cost | ||||||||||||
| Current service cost | 9,393 | - | 9,393 | |||||||||
| Past service cost and gain on settlements | (2,328 | ) | - | (2,328 | ) | |||||||
| Net interest expense (income) | 5,311 | (3,500 | ) | 1,811 | ||||||||
| Recognized in profit or loss | 12,376 | (3,500 | ) | 8,876 | ||||||||
(Continued)
| Present value of the defined benefit obligation | Fair value of the plan assets | Net defined benefit liability (asset) | ||||||||||
| US$ (Note 4) | US$ (Note 4) | US$ (Note 4) | ||||||||||
| Remeasurement | ||||||||||||
| Return on plan assets (excluding amounts included in net interest) | $ | - | $ | 1,759 | $ | 1,759 | ||||||
| Actuarial loss arising from changes in financial assumptions | 1,918 | - | 1,918 | |||||||||
| Actuarial gain arising from experience adjustments | (10,631 | ) | - | (10,631 | ) | |||||||
| Actuarial loss arising from changes in demographic assumptions | 26 | - | 26 | |||||||||
| Recognized in other comprehensive income | (8,687 | ) | 1,759 | (6,928 | ) | |||||||
| Contributions from the employer | - | (16,356 | ) | (16,356 | ) | |||||||
| Benefits paid from the pension fund | (23,307 | ) | 23,307 | - | ||||||||
| Benefits paid from the Group | (3,258 | ) | - | (3,258 | ) | |||||||
| Exchange differences on foreign plans | 6,707 | (2,646 | ) | 4,061 | ||||||||
| Balance at December 31, 2017 | $ | 266,891 | $ | (146,470 | ) | $ | 120,421 | |||||