XML 140 R127.htm IDEA: XBRL DOCUMENT v3.19.1
Retirement Benefit Plans - Amounts Recognized in Consolidated Statements of Profit or Loss and Other Comprehensive Income of Defined Benefit Plans (Detail)
$ in Millions, $ in Millions
12 Months Ended
Dec. 31, 2018
TWD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
TWD ($)
Dec. 31, 2016
TWD ($)
Disclosure of defined benefit plans [abstract]        
Current service cost $ 137.7   $ 145.0 $ 132.8
Net interest expense 144.1   126.5 139.4
Components of defined benefit costs recognized in profit or loss 281.8   271.5 272.2
Remeasurement on the net defined benefit liability:        
Return on plan assets (excluding amounts included in net interest expense) (71.3)   29.3 45.7
Actuarial loss arising from experience adjustments 334.7   483.9 38.2
Actuarial loss (gain) arising from changes in financial assumptions 597.8   (258.5) 694.6
Actuarial loss arising from changes in demographic assumptions       278.7
Components of defined benefit costs recognized in other comprehensive income 861.2 $ 28.1 254.7 1,057.2
Total $ 1,143.0   $ 526.2 $ 1,329.4