XML 158 R136.htm IDEA: XBRL DOCUMENT v3.21.1
Income Tax - Reconciliation of Income before Income Tax and Income Tax Expense Recognized in Profit or Loss (Detail)
$ in Millions, $ in Millions
 12 Months Ended
Dec. 31, 2020
TWD ($)
Dec. 31, 2020
USD ($)
Dec. 31, 2019
TWD ($)
Dec. 31, 2018
TWD ($)
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]        
Income before tax $ 584,746.3   $ 389,862.1 $ 397,543.1
Income tax expense at the statutory rate 118,831.3   79,056.5 80,872.5
Tax effect of adjusting items:        
Nondeductible (deductible) items in determining taxable income 1,015.9   (4,183.5) 2,533.4
Tax-exempt income (65,988.1)   (39,808.1) (54,543.5)
Additional income tax under the Alternative Minimum Tax Act 18,872.8   10,367.9 21,455.9
Additional income tax on unappropriated earnings 14,747.3   7,628.1 16,294.5
Effect of tax rate changes on deferred income tax       (1,474.8)
The origination and reversal of temporary differences (6,275.2)   (1,065.1) (3,072.5)
Income tax credits (26.5)   (5,925.4) (6,028.4)
Tax effect of adjusting items 81,177.5   46,070.4 56,037.0
Income tax adjustments on prior years (7,589.4)   (10,193.8) (21,753.0)
Other income tax adjustments 150.2   (41.5) 152.9
Income tax expense recognized in profit or loss $ 73,738.3 $ 2,626.0 $ 35,835.1 $ 34,436.9