XML 78 R147.htm IDEA: XBRL DOCUMENT v3.20.1
Retirement Benefit Plans - Summary of Maturity Analysis of Undiscounted Pension Benefit (Detail)
$ in Thousands, $ in Thousands
Dec. 31, 2019
TWD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
TWD ($)
Disclosure of defined benefit plans [line items]      
Maturity analysis of undiscounted pension benefit $ 14,720,029 $ 492,143 $ 15,578,025
Less than 1 year [member]      
Disclosure of defined benefit plans [line items]      
Maturity analysis of undiscounted pension benefit 422,067 14,111 368,592
1-5 years [member]      
Disclosure of defined benefit plans [line items]      
Maturity analysis of undiscounted pension benefit 2,081,540 69,593 1,886,738
More than 5 years [member]      
Disclosure of defined benefit plans [line items]      
Maturity analysis of undiscounted pension benefit $ 12,216,422 $ 408,439 $ 13,322,695