XML 154 R136.htm IDEA: XBRL DOCUMENT v3.22.1
Income Tax - Income Tax Expense Recognized in Other Comprehensive Income (Detail) - TWD ($)
$ in Millions
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Income tax relating to components of other comprehensive income [abstract]      
Related to remeasurement of defined benefit obligation $ (29.1) $ 422.1 $ (30.4)
Related to unrealized gain/loss on investments in equity instruments at FVTOCI (56.2) 0.6 9.4
Related to gain/loss on cash flow hedges (3.4) 0.0 0.0
Deferred income tax benefit (expense) $ (88.7) $ 422.7 $ (21.0)