XML 23 R103.htm IDEA: XBRL DOCUMENT v3.20.1
Property, Plant and Equipment - Summary of assets subject to operating leases (Detail)
$ in Millions, $ in Millions
 12 Months Ended
Dec. 31, 2019
TWD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
TWD ($)
Dec. 31, 2017
TWD ($)
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance $ 1,072,050.3   $ 1,062,542.3  
Additions 564,283.0   300,024.4 $ 322,493.9
Ending balance 1,352,377.4 $ 45,214.9 1,072,050.3 1,062,542.3
Buildings used to operating leases [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Ending balance 63.5      
Cost [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 3,372,779.1   3,080,615.1 2,773,250.8
Additions     300,024.4 322,493.9
Ending balance     3,372,779.1 3,080,615.1
Accumulated depreciation [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 2,300,728.8   2,018,072.8 1,775,473.1
Additions     288,124.9 255,796.0
Ending balance     2,300,728.8 2,018,072.8
Accumulated depreciation [member] | Buildings used to operating leases [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Ending balance 63.5      
Buildings [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 200,340.2   184,688.1  
Ending balance     200,340.2 184,688.1
Buildings [member] | Cost [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 418,714.3   379,134.6 304,404.5
Additions     40,396.4 75,594.7
Ending balance     418,714.3 379,134.6
Buildings [member] | Cost [member] | Buildings used to operating leases [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 562.6      
Ending balance 562.6   562.6  
Buildings [member] | Accumulated depreciation [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 218,374.1   194,446.5 174,349.1
Additions     24,293.4 20,844.6
Ending balance     218,374.1 $ 194,446.5
Buildings [member] | Accumulated depreciation [member] | Buildings used to operating leases [member]        
Disclosure Of Property Plant And Equipment Subject To Operating Lease [Line Items]        
Beginning balance 474.9      
Additions 24.2      
Ending balance $ 499.1   $ 474.9