Hedging Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2022

Disclosure of detailed information about hedging instruments [abstract]

Summary of Hedging Derivative Financial Instruments

The following tables summarized the information relating to the hedges for foreign currency risk.

December 31, 2020

Notional

Forward

Line Item in

Carrying Amount

Change in Fair Values of Hedging Instruments Used for Calculating Hedge

Hedging Instruments

Currency

Amount

Maturity

Rate

Balance Sheet

Asset

Liability

Ineffectiveness

(In Millions)

NT$

NT$

NT$

(In Millions)

Cash flow hedge

Forecast purchases -   forward exchange   contracts

NT$/EUR

NT$ 201/ EUR 6

2021.03

$

34.45

Hedging financial assets (liabilities)

$

2

$

—

$

2

	Change in Value of Hedged  Item Used for			Accumulated Gain or Loss on Hedging Instruments in Other Equity
Hedged Items	Calculating Hedge Ineffectiveness			Continuing Hedges		Hedge Accounting No Longer Applied
	NT$			NT$		NT$
				(In Millions)
Cash flow hedge
Forecast equipment purchases	$	(2	)	$	2	$	—

December 31, 2021

Notional

Forward

Line Item in

Carrying Amount

Change in Fair Values of Hedging Instruments Used for Calculating Hedge

Hedging Instruments

Currency

Amount

Maturity

Rate

Balance Sheet

Asset

Liability

Ineffectiveness

(In Millions)

NT$

NT$

NT$

(In Millions)

Cash flow hedge

Forecast purchases -   forward exchange   contracts

NT$/EUR

NT$ 228/ EUR 7

2022.03

$

32.54

Hedging financial assets (liabilities)

$

—

$

8

$

(10

)

	Change in Value of Hedged  Item Used for		Accumulated Gain or Loss on Hedging Instruments in Other Equity
Hedged Items	Calculating Hedge Ineffectiveness		Continuing Hedges			Hedge Accounting No Longer Applied
	NT$		NT$			NT$
			(In Millions)
Cash flow hedge
Forecast equipment purchases	$	10	$	(8	)	$	—

December 31, 2022

Notional

Forward

Line Item in

Carrying Amount

Change in Fair Values of Hedging Instruments Used for Calculating Hedge

Hedging Instruments

Currency

Amount

Maturity

Rate

Balance Sheet

Asset

Liability

Ineffectiveness

(In Millions)

NT$

NT$

NT$

(In Millions)

Cash flow hedge

Forecast purchases -   forward exchange   contracts

NT$/EUR

NT$ 423/ EUR 13

2023.03

$

31.69

Hedging financial assets (liabilities)

$

13

$

—

$

21

	Change in Value of Hedged  Item Used for			Accumulated Gain or Loss on Hedging Instruments in Other Equity
Hedged Items	Calculating Hedge Ineffectiveness			Continuing Hedges		Hedge Accounting No Longer Applied
	NT$			NT$		NT$
				(In Millions)
Cash flow hedge
Forecast equipment purchases	$	(21	)	$	13	$	—

Summary of Hedging Transaction and Reclassification Affected Comprehensive Income

Year ended December 31, 2020

	Comprehensive Income						Reclassification from Equity to Assets and the Adjusted Line Item
	Hedging Gain or Loss		Amount of Hedge Ineffectiveness		Line Item in Which Hedge		Amount Reclassified to Assets and		Due to Hedged Future Cash Flows No
Hedge	Recognized		Recognized in		Ineffectiveness		the Adjusted		Longer Expected
Transaction	in OCI		Profit or Loss		is Included		Line Item		to Occur
	NT$		NT$		NT$		NT$		NT$
	(In Millions)
Cash flow hedge
Forecast   equipment   purchases	$	2	$	—		—	$	21	$	—
							Construction in progress and equipment to be accepted		Other gains and losses

Year ended December 31, 2021

Comprehensive Income

Reclassification from Equity to Assets and the Adjusted Line Item

Hedging Gain or Loss

Amount of Hedge Ineffectiveness

Line Item in Which Hedge

Amount Reclassified to Assets and

Due to Hedged Future Cash Flows No

Hedge

Recognized

Recognized in

Ineffectiveness

the Adjusted

Longer Expected

Transaction

in OCI

Profit or Loss

is Included

Line Item

to Occur

NT$

NT$

NT$

NT$

NT$

(In Millions)

Cash flow hedge

Forecast   equipment   purchases

$

(10

)

$

—

—

$

(43

)

$

—

Construction in progress and equipment to be accepted

Other gains and losses

Year ended December 31, 2022

	Comprehensive Income						Reclassification from Equity to Assets and the Adjusted Line Item
	Hedging Gain or Loss		Amount of Hedge Ineffectiveness		Line Item in Which Hedge		Amount Reclassified to Assets and		Due to Hedged Future Cash Flows No
Hedge	Recognized		Recognized in		Ineffectiveness		the Adjusted		Longer Expected
Transaction	in OCI		Profit or Loss		is Included		Line Item		to Occur
	NT$		NT$		NT$		NT$		NT$
	(In Millions)
Cash flow hedge
Forecast   equipment   purchases	$	21	$	—		—	$	6	$	—
							Construction in progress and equipment to be accepted		Other gains and losses