Retirement Benefit Plans - Maturity Analysis of Undiscounted Benefit Payments (Detail) $ in Millions	12 Months Ended
Dec. 31, 2022 TWD ($)
Disclosure of defined benefit plans [abstract]
2023	$ 2,673
2024	6,184
2025	9,313
2026	10,556
2027 and thereafter	36,623
Total	$ 65,349

Estimated future benefit payments five fiscal years thereafter.

No definition available.

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Namespace Prefix:	cht_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration