XML 65 R44.htm IDEA: XBRL DOCUMENT v3.25.0.1

Pension and Severance Plans (Tables)

12 Months Ended

Dec. 31, 2024

Retirement Benefits [Abstract]

Schedule of Accrued Severance Obligation

The changes to the balance of our accrued severance plan obligations are as follows:

			For the Year Ended December 31,
			2024						2023
			(In thousands)
Balance at January 1			$	47,906					$	56,289
Provision of severance benefits			3,142						1,653
Severance payments			(1,416)						(8,770)
Foreign currency (gain) loss			(6,194)						(1,266)
Balance at December 31			43,438						47,906
Payments remaining with the National Pension Fund			(101)						(119)
Total accrued severance plan obligations at December 31			43,337						47,787
Less current portion of accrued severance plan obligations (Note 10) (1)			12,231						7,906
Non-current portion of accrued severance plan obligations			$	31,106					$	39,881

(1)In December 2024, some employees accepted our offer to convert their Korean severance and defined benefit pension plan participation to a defined contribution plan. This will result in the conversion of approximately $5 million of obligations from our Korean severance plan to a defined contribution plan, which is expected to be funded during the first quarter of 2025.

Schedule of Changes in Projected Benefit Obligations and Fair Value of Plan Assets

The following table summarizes the changes to the Plans’ benefit obligations, fair value of the Plans’ assets and the funded status of the Plans at December 31, 2024 and 2023:

			For the Year Ended December 31,
			2024						2023
			(In thousands)
Change in projected benefit obligation:
Projected benefit obligation at January 1			$	164,281					$	159,760
Service cost			13,645						15,032
Interest cost			5,718						6,202
Benefits paid			(11,320)						(14,056)
Actuarial (gain) loss			2,458						4,150
Effects of curtailment			(320)						(617)
Settlement			(883)						(1,073)
Foreign exchange (gain) loss			(14,423)						(5,117)
Projected benefit obligation at December 31			159,156						164,281
Change in plan assets:
Fair value of plan assets at January 1			129,196						127,338
Actual gain (loss) on plan assets			8,918						12,325
Employer contributions			12,165						7,368
Settlement			(883)						(1,073)
Benefits paid			(11,320)						(14,056)
Foreign exchange gain (loss)			(12,794)						(2,706)
Fair value of plan assets at December 31			125,282						129,196
Funded status of the Plans at December 31			$	(33,874)					$	(35,085)

Schedule of Defined Benefit Plans - Balance Sheet

			December 31,
			2024						2023
			(In thousands)
Amounts recognized in the Consolidated Balance Sheets consist of:
Prepaid benefit cost (included in non-current assets)			$	5,991					$	12,039
Accrued benefit liability (included in pension and severance obligations) (1)			(39,865)						(47,124)
Net amount recognized at year end			$	(33,874)					$	(35,085)

(1)As of December 31, 2024, $0.9 million was recognized in accrued expenses.

Schedule of Amounts Recognized in Other Comprehensive Income (Loss)

The following table summarizes, by component, the change in accumulated other comprehensive income (loss), net of tax related to our Plans:

			Prior Service Cost						Actuarial Net Gain (Loss)						Total
			(In thousands)
Balance at December 31, 2022			$	602					$	13,618					$	14,220
Amortization and settlement gain included in net periodic pension cost			—						(46)						(46)
Net gain (loss) arising during period			—						1,731						1,731
Adjustments to unrealized components of defined benefit pension plan included in other comprehensive income (loss)			—						1,685						1,685
Balance at December 31, 2023			$	602					$	15,303					$	15,905
Amortization and settlement gain included in net periodic pension cost			—						(388)						(388)
Net gain (loss) arising during period			—						1,053						1,053
Adjustments to unrealized components of defined benefit pension plan included in other comprehensive income (loss)			—						665						665
Balance at December 31, 2024			$	602					$	15,968					$	16,570

Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets

Information for pension plans with benefit obligations in excess of plan assets is as follows:

			December 31,
			2024						2023
			(In thousands)
Plans with underfunded or non-funded projected benefit obligation:
Aggregate projected benefit obligation			$	92,191					$	100,662
Aggregate fair value of plan assets			52,326						53,539
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate accumulated benefit obligation			55,646						60,638
Aggregate fair value of plan assets			20,122						21,304

Schedule of Components of Net Periodic Pension Cost

The following table summarizes total pension expense:

			For the Year Ended December 31,
			2024						2023						2022
			(In thousands)
Components of net periodic pension cost and total pension expense:
Service cost			$	13,645					$	15,032					$	20,072
Interest cost			5,718						6,202						4,731
Expected return on plan assets			(5,554)						(5,144)						(5,605)
Recognized actuarial (gain) loss			(462)						(156)						53
Net periodic pension cost			13,347						15,934						19,251
Curtailment (gain) loss			(320)						(617)						—
Settlement (gain) loss			33						132						(1,374)
Total pension expense			$	13,060					$	15,449					$	17,877

Schedule of Weighted-average Assumptions Used in Computing the Net Periodic Pension Cost and Projected Benefit Obligations

The following table summarizes the weighted-average assumptions used in computing the net periodic pension cost and projected benefit obligations:

			For the Year Ended December 31,
			2024						2023						2022
Discount rate for determining net periodic pension cost			3.8		%				4.2		%				2.6		%
Discount rate for determining benefit obligations at December 31			3.8		%				3.8		%				4.2		%
Rate of compensation increase for determining net periodic pension cost			3.7		%				3.6		%				3.7		%
Rate of compensation increase for determining benefit obligations at December 31			3.8		%				3.7		%				3.6		%
Expected rate of return on plan assets for determining net periodic pension cost			4.5		%				4.1		%				3.8		%

Schedule of Allocation of Plan Assets

The current rate of return assumption targets are based on asset allocation strategies as follows:

			Allocation
			Debt						Equity						Other
Japan defined benefit plan			64		%				34		%				2		%
Korea defined benefit plan			30		%				20		%				50		%
Philippine defined benefit plan			50		%				45		%				5		%

The fair value of our pension plan assets, by asset category utilizing the fair value hierarchy as discussed in Note 16, is as follows:

			December 31, 2024																		December 31, 2023
			Level 1						Level 2												Total						Level 1						Level 2									Total
			(In thousands)																		(In thousands)
Cash and cash equivalents			$	749					$	—											$	749					$	217					$	—								$	217
Equity securities			14,276						—												14,276						13,680						—									13,680
Debt securities
Government bonds			3,712						—												3,712						3,674						—									3,674
Corporate bonds			1,259						—												1,259						1,130						—									1,130
Treasury notes			11,881						—												11,881						11,993						—									11,993
Mutual and commingled funds
Equity funds			11,950						7,270												19,220						29,016						7,807									36,823
Debt funds			18,210						12,516												30,726						12,031						13,163									25,194
Guaranteed investment contracts			—						30,365												30,365						—						23,189									23,189
Taiwan retirement fund			12,428						—												12,428						12,478						—									12,478
Other, net			—						666												666						—						818									818
Total fair value of pension plan assets			$	74,465					$	50,817											$	125,282					$	84,219					$	44,977								$	129,196

Schedule of Expected Benefit Payments

The estimated future benefit payments related to our foreign defined benefit plans are as follows:

			Payments
			(In thousands)
2025			$	9,307
2026			11,145
2027			13,419
2028			14,037
2029			13,922
2030 to 2034			97,256

X

- Definition

Schedule Of Accrued Severance Obligation [Table Text Block]

+ References

No definition available.

+ Details

Name:	amkr_ScheduleOfAccruedSeveranceObligationTableTextBlock
Namespace Prefix:	amkr_
Data Type:	dtr-types1:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the change in the benefit obligation, fair value of plan assets, and funded status of pension plans or other employee benefit plans.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Subparagraph (a)(b)(c)
-Paragraph 1
-SubTopic 20
-Topic 715
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ChangesInProjectedBenefitObligationsFairValueOfPlanAssetsAndFundedStatusOfPlanTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the major categories of plan assets of pension plans and/or other employee benefit plans. This information may include, but is not limited to, the target allocation of plan assets, the fair value of each major category of plan assets, and the level within the fair value hierarchy in which the fair value measurements fall.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (d)(5)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the amounts that are recognized in the balance sheet (or statement of financial position) for pension plans and/or other employee benefit plans, showing separately the assets and current and noncurrent liabilities (if applicable) recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAmountsRecognizedInBalanceSheetTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the net gain (loss) and net prior service cost or credit recognized in other comprehensive income (loss) for the period for pension plans and/or other employee benefit plans, and reclassification adjustments of other comprehensive income (loss) for the period, as those amounts, including amortization of the net transition asset or obligation, are recognized as components of net periodic benefit cost.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of assumption used to determine benefit obligation and net periodic benefit cost of defined benefit plan. Includes, but is not limited to, discount rate, rate of compensation increase, expected long-term rate of return on plan assets and interest crediting rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (k)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfAssumptionsUsedTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of benefit obligation and plan assets for defined benefit pension plan with projected benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-3

+ Details

Name:	us-gaap_ScheduleOfBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of benefits expected to be paid by pension plans and/or other employee benefit plans in each of the next five fiscal years and in the aggregate for the five fiscal years thereafter.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (f)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 715
-SubTopic 20
-Subparagraph (h)
-Name Accounting Standards Codification
-Paragraph 1
-Section 50
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480506/715-20-50-1

+ Details

Name:	us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration