XML 65 R139.htm IDEA: XBRL DOCUMENT v3.20.1
Other Operating Income and Expenses, Net - Summary of Other Operating Income and Expenses, Net (Detail)
$ in Millions, $ in Millions
 12 Months Ended
Dec. 31, 2019
TWD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
TWD ($)
Dec. 31, 2017
TWD ($)
Other Operating Income And Expense Net [abstract]        
Loss on disposal or retirement of property, plant and equipment, net $ (950.0) $ (31.8) $ (1,005.6) $ (1,097.9)
Reversal of impairment loss (impairment loss) on property, plant and equipment 301.4 10.1 (423.5)  
Others 152.3   (672.4) (267.6)
Other operating income and expenses, net $ (496.3) $ (16.6) $ (2,101.5) $ (1,365.5)