Income Tax - Summary of Reconciliation of Income Tax Expense (Detail) $ in Thousands, $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
|
Dec. 31, 2023
TWD ($)
|
Dec. 31, 2023
USD ($)
|
Dec. 31, 2022
TWD ($)
|
Dec. 31, 2021
TWD ($)
|
|
| Major components of tax expense (income) [abstract] | ||||
| Profit before income tax | $ 42,611,823 | $ 1,391,634 | $ 81,763,628 | $ 80,193,769 |
| Income tax expense calculated at the statutory rates | 18,763,311 | 612,780 | 35,906,719 | 33,697,736 |
| Nontaxable expense (income) in determining taxable income | 1,132,092 | 36,972 | (177,734) | 357,936 |
| Tax-exempt income | (7,369,986) | (240,692) | (14,789,999) | (14,578,355) |
| Additional income tax on unappropriated earnings | (3,449,958) | (112,670) | 844,855 | 3,684,138 |
| Income tax credits | (1,921,721) | (62,760) | (2,514,002) | (1,654,821) |
| The origination and reversal of temporary differences | 69,767 | 2,278 | 1,304,931 | 78,544 |
| Income tax adjustments on prior years | (31,609) | (1,032) | (209,150) | (112,527) |
| Unrecognized deferred tax liability for temporary differences associated with investments | (2,557,436) | (83,522) | (3,523,716) | (6,135,120) |
| Unrecognized loss carryforwards | 455,437 | 14,874 | 271,730 | 288,025 |
| Withholding tax | 12,433 | 406 | 31,900 | 87,175 |
| House and land transactions income tax | 201,633 | 6,585 | 0 | 0 |
| Land value increment tax | 0 | 0 | 0 | 117,341 |
| Capital gains tax | 0 | 0 | 0 | 2,113,700 |
| Income tax expense recognized in profit or loss | $ 5,303,963 | $ 173,219 | $ 17,145,534 | $ 17,943,772 |