Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2021

Retirement Benefits [Abstract]

Schedule of amounts recognized in balance sheet

Changes in benefit obligation and plan assets and amounts recognized in the Consolidated Balance Sheets at December 31 were as follows:

	Pension Benefits				Other Postretirement Benefits
	2021		2020		2021		2020
Change in benefit obligation:	(In thousands)
Benefit obligation at beginning of year	$	437,360	$	421,166	$	86,155	$	83,614
Service cost	—		—		1,600		1,532
Interest cost	9,819		12,093		1,862		2,437
Plan participants' contributions	—		—		641		752
Actuarial (gain) loss	(12,140)		27,737		(12,802)		2,203
Benefits paid	(23,542)		(23,636)		(3,996)		(4,383)
Benefit obligation at end of year	411,497		437,360		73,460		86,155
Change in net plan assets:
Fair value of plan assets at beginning of year	383,834		365,264		101,639		94,587
Actual return on plan assets	12,817		42,206		1,398		10,249
Employer contribution	—		—		476		434
Plan participants' contributions	—		—		641		752
Benefits paid	(23,542)		(23,636)		(3,996)		(4,383)
Fair value of net plan assets at end of year	373,109		383,834		100,158		101,639
Funded status - over (under)	$	(38,388)	$	(53,526)	$	26,698	$	15,484
Amounts recognized in the Consolidated Balance Sheets at December 31:
Noncurrent assets - other	$	—	$	—	$	45,863	$	36,769
Other accrued liabilities	—		—		544		622
Noncurrent liabilities - other	38,388		53,526		18,621		20,663
Benefit obligation assets (liabilities) - net amount recognized	$	(38,388)	$	(53,526)	$	26,698	$	15,484
Amounts recognized in accumulated other comprehensive loss:
Actuarial loss	$	25,976	$	27,527	$	2,367	$	5,557
Prior service credit	—		—		(290)		(634)
Total	$	25,976	$	27,527	$	2,077	$	4,923
Amounts recognized in regulatory assets or liabilities:
Actuarial (gain) loss	$	142,166	$	154,013	$	(14,727)	$	(8,228)
Prior service credit	—		—		(5,193)		(6,808)
Total	$	142,166	$	154,013	$	(19,920)	$	(15,036)

The projected benefit obligation, accumulated benefit obligation and fair value of plan assets for the pension plans with accumulated benefit obligations in excess of plan assets

The pension plans all have accumulated benefit obligations in excess of plan assets. The projected benefit obligation, accumulated benefit obligation and fair value of plan assets for these plans at December 31 were as follows:

	2021		2020
	(In thousands)
Projected benefit obligation	$	411,497	$	437,360
Accumulated benefit obligation	$	411,497	$	437,360
Fair value of plan assets	$	373,109	$	383,834

The projected benefit obligation and accumulated benefit obligation for these plans at December 31 were as follows:

	2021		2020
	(In thousands)
Projected benefit obligation	$	92,918	$	101,242
Accumulated benefit obligation	$	92,918	$	101,242

Components of net periodic benefit cost

The components of net periodic benefit cost (credit), other than the service cost component, are included in other income on the Consolidated Statements of Income. Prior service credit is amortized on a straight-line basis over the average remaining service period of active participants. These components related to the Company's pension and other postretirement benefit plans for the years ended December 31 were as follows:

	Pension Benefits						Other Postretirement Benefits
	2021		2020		2019		2021		2020		2019
Components of net periodic benefit cost (credit):	(In thousands)
Service cost	$	—	$	—	$	—	$	1,600	$	1,532	$	1,142
Interest cost	9,819		12,093		15,225		1,862		2,437		2,986
Expected return on assets	(19,576)		(19,949)		(18,236)		(5,098)		(5,019)		(4,804)
Amortization of prior service credit	—		—		—		(1,398)		(1,398)		(1,398)
Recognized net actuarial loss	8,017		7,172		5,548		24		287		353
Net periodic benefit cost (credit), including amount capitalized	(1,740)		(684)		2,537		(3,010)		(2,161)		(1,721)
Less amount capitalized	—		—		—		150		156		113
Net periodic benefit cost (credit)	(1,740)		(684)		2,537		(3,160)		(2,317)		(1,834)
Other changes in plan assets and benefit obligations recognized in accumulated comprehensive loss:
Net (gain) loss	(265)		934		(144)		(2,811)		(259)		(127)
Amortization of actuarial loss	(1,286)		(1,155)		(904)		(135)		(306)		(110)
Amortization of prior service credit	—		—		—		100		101		100
Total recognized in accumulated other comprehensive loss	(1,551)		(221)		(1,048)		(2,846)		(464)		(137)
Other changes in plan assets and benefit obligations recognized in regulatory assets or liabilities:
Net (gain) loss	(5,116)		4,546		189		(6,292)		(3,793)		(8,168)
Amortization of actuarial gain (loss)	(6,731)		(6,017)		(4,644)		110		19		(242)
Amortization of prior service credit	—		—		—		1,298		1,297		1,297
Total recognized in regulatory assets or liabilities	(11,847)		(1,471)		(4,455)		(4,884)		(2,477)		(7,113)
Total recognized in net periodic benefit cost (credit), accumulated other comprehensive loss and regulatory assets or liabilities	$	(15,138)	$	(2,376)	$	(2,966)	$	(10,890)	$	(5,258)	$	(9,084)

The components of net periodic benefit cost are included in other income on the Consolidated Statements of Income. These components related to the Company's nonqualified defined benefit plans for the years ended December 31 were as follows:

	2021		2020		2019
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	—	$	58	$	109
Interest cost	1,912		2,606		3,473
Recognized net actuarial loss	1,164		1,192		764
Net periodic benefit cost	$	3,076	$	3,856	$	4,346

Weighted average assumptions used to determine benefit obligations and net periodic benefit costs

Weighted average assumptions used to determine benefit obligations at December 31 were as follows:

	Pension Benefits				Other Postretirement Benefits
	2021		2020		2021		2020
Discount rate	2.64	%	2.30	%	2.66	%	2.30	%
Expected return on plan assets	6.00	%	6.00	%	5.50	%	5.50	%
Rate of compensation increase	N/A		N/A		3.00	%	3.00	%

Weighted average assumptions used to determine net periodic benefit cost (credit) for the years ended December 31 were as follows:

	Pension Benefits				Other Postretirement Benefits
	2021		2020		2021		2020
Discount rate	2.30	%	2.96	%	2.30	%	3.00	%
Expected return on plan assets	6.00	%	6.25	%	5.50	%	5.75	%
Rate of compensation increase	N/A		N/A		3.00	%	3.00	%

Weighted average assumptions used at December 31 were as follows:

	2021		2020
Benefit obligation discount rate	2.39	%	1.97	%
Benefit obligation rate of compensation increase	N/A		N/A
Net periodic benefit cost discount rate	1.97	%	2.73	%
Net periodic benefit cost rate of compensation increase	N/A		N/A

Health care rate assumptions for the Company's other postretirement benefit plans

Health care rate assumptions for the Company's other postretirement benefit plans as of December 31 were as follows:

	2021		2020
Health care trend rate assumed for next year	7.0	%	7.0	%
Health care cost trend rate - ultimate	4.5	%	4.5	%
Year in which ultimate trend rate achieved	2031		2031

Benefit payments expected to be paid

The following benefit payments, which reflect future service, as appropriate, and expected Medicare Part D subsidies at December 31, 2021, are as follows:

Years	Pension Benefits		Other Postretirement Benefits		Expected Medicare Part D Subsidy
			(In thousands)
2022	$	24,644	$	4,393	$	70
2023	24,766		4,522		65
2024	24,897		4,572		58
2025	24,739		4,612		52
2026	24,571		4,642		46
2027-2031	117,413		17,867		157

The amount of future benefit payments for the unfunded, nonqualified defined benefit plans at December 31, 2021, are expected to aggregate as follows:

	2022		2023		2024		2025		2026		2027-2031
	(In thousands)
Nonqualified benefits	$	6,877	$	6,890	$	7,354	$	7,537	$	7,609	$	31,983

The fair value of the pension and postretirement net plan assets by class

The fair value of the Company's pension plans' assets (excluding cash) by class were as follows:

	Fair Value Measurements  at December 31, 2021, Using
	Quoted Prices in Active Markets for Identical Assets  (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable  Inputs  (Level 3)		Balance at December 31, 2021
	(In thousands)
Assets:
Cash equivalents	$	—	$	4,637	$	—	$	4,637
Equity securities:
U.S. companies	7,483		—		—		7,483
International companies	—		1,279		—		1,279
Collective and mutual funds (a)	167,093		41,383		—		208,476
Corporate bonds	—		125,167		—		125,167
Municipal bonds	—		7,507		—		7,507
U.S. Government securities	7,113		1,902		—		9,015
Pooled separate accounts (b)	—		3,088		—		3,088
Investments measured at net asset value (c)	—		—		—		6,457
Total assets measured at fair value	$	181,689	$	184,963	$	—	$	373,109

(a)Collective and mutual funds invest approximately 37 percent in corporate bonds, 19 percent in common stock of international companies, 16 percent in common stock of large-cap U.S. companies, 9 percent in U.S. Government securities and 19 percent in other investments.

(b)Pooled separate accounts are invested 100 percent in cash and cash equivalents.

(c)In accordance with ASC 820 - Fair Value, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the line items presented in the statement of financial condition.

	Fair Value Measurements  at December 31, 2020, Using
	Quoted Prices in Active Markets for Identical Assets  (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable  Inputs  (Level 3)		Balance at December 31, 2020
	(In thousands)
Assets:
Cash equivalents	$	—	$	7,841	$	—	$	7,841
Equity securities:
U.S. companies	12,844		—		—		12,844
International companies	—		1,727		—		1,727
Collective and mutual funds (a)	177,397		55,788		—		233,185
Corporate bonds	—		92,809		—		92,809
Municipal bonds	—		10,126		—		10,126
U.S. Government securities	11,177		2,695		—		13,872
Investments measured at net asset value (b)	—		—		—		11,430
Total assets measured at fair value	$	201,418	$	170,986	$	—	$	383,834

(a)Collective and mutual funds invest approximately 36 percent in corporate bonds, 24 percent in common stock of international companies, 18 percent in common stock of large-cap U.S. companies, 8 percent in cash equivalents, 5 percent in U.S. Government securities and 9 percent in other investments.

(b)In accordance with ASC 820 - Fair Value, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the line items presented in the statement of financial condition.

The fair value of the Company's other postretirement benefit plans' assets (excluding cash) by asset class were as follows:

	Fair Value Measurements  at December 31, 2021, Using
	Quoted Prices in Active Markets for Identical Assets  (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable  Inputs  (Level 3)		Balance at December 31, 2021
	(In thousands)
Assets:
Cash equivalents	$	—	$	4,281	$	—	$	4,281
Equity securities:
U.S. companies	2,332		—		—		2,332
International companies	—		1		—		1
Collective and mutual funds (a)	4		90		—		94
Insurance contract (b)	—		93,447		—		93,447
Investments measured at net asset value (c)	—		—		—		3
Total assets measured at fair value	$	2,336	$	97,819	$	—	$	100,158

(a)Collective and mutual funds invest approximately 37 percent in corporate bonds, 19 percent in common stock of international companies, 16 percent in common stock of large-cap U.S. companies, 9 percent in U.S. Government securities and 19 percent in other investments.

(b)The insurance contract invests approximately 58 percent in corporate bonds, 13 percent in U.S. Government securities, 13 percent in common stock of large-cap U.S. companies, 5 percent in common stock of small-cap U.S. companies and 11 percent in other investments.

(c)In accordance with ASC 820 - Fair Value, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the line items presented in the statement of financial condition.

	Fair Value Measurements  at December 31, 2020, Using
	Quoted Prices in Active Markets for Identical Assets  (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable  Inputs  (Level 3)		Balance at December 31, 2020
	(In thousands)
Assets:
Cash equivalents	$	—	$	3,517	$	—	$	3,517
Equity securities:
U.S. companies	1,850		—		—		1,850
International companies	—		2		—		2
Collective and mutual funds (a)	10		147		—		157
Insurance contract (b)	—		96,103		—		96,103
Investments measured at net asset value (c)	—		—		—		10
Total assets measured at fair value	$	1,860	$	99,769	$	—	$	101,639

(a)Collective and mutual funds invest approximately 36 percent in corporate bonds, 24 percent in common stock of international companies, 18 percent in common stock of large-cap U.S. companies, 8 percent in cash equivalents, 5 percent in U.S. Government securities and 9 percent in other investments.

(b)The insurance contract invests approximately 67 percent in corporate bonds, 10 percent in common stock of large-cap U.S. companies, 12 percent in U.S. Government securities, 4 percent in common stock of small-cap U.S. companies, 1 percent in cash equivalents and 6 percent in other investments.

(c)In accordance with ASC 820 - Fair Value, certain investments that were measured at net asset value per share (or its equivalent) have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the line items presented in the statement of financial condition.

The amount of investments that the Company anticipates using to satisfy obligations under these plans at December 31 was as follows:

	2021		2020
	(In thousands)
Investments
Insurance contract*	$	109,603	$	100,104
Life insurance**	38,356		39,779
Other	10,190		8,917
Total investments	$	158,149	$	148,800

*For more information on the insurance contract, see Note 8.

**Investments of life insurance are carried on plan participants (payable upon the employee's death).

Schedule of Multiemployer Plans [Table Text Block]

	EIN/Pension Plan Number	Pension Protection Act Zone Status		FIP/RP Status Pending/Implemented	Contributions						Surcharge Imposed	Expiration Date of Collective Bargaining Agreement
Pension Fund		2021	2020		2021		2020		2019
					(In thousands)
Edison Pension Plan	936061681-001	Green	Green	No	$	18,331	$	16,121	$	12,252	No	12/31/2023
IBEW Local 212 Pension Trust	316127280-001	Green as of 4/30/2021	Green as of 4/30/2020	No	1,733		1,521		1,110		No	6/1/2025
IBEW Local 357 Pension Plan A	886023284-001	Green	Green	No	6,485		9,913		10,162		No	5/31/2024
IBEW Local 82 Pension Plan	316127268-001	Green as of 6/30/2021	Green as of 6/30/2020	No	1,353		1,373		1,662		No	12/3/2023
Idaho Plumbers and Pipefitters Pension Plan	826010346-001	Green as of 5/31/2021	Green as of 5/31/2020	No	1,528		1,370		1,307		No	3/31/2023
National Electrical Benefit Fund	530181657-001	Green	Green	No	14,361		14,484		12,679		No	5/31/2021- 5/31/2026	*
Pension and Retirement Plan of Plumbers and Pipefitters Local 525	886003864-001	Green	Green	No	4,345		6,266		4,747		No	9/30/2024
Pension Trust Fund for Operating Engineers	946090764-001	Yellow	Yellow	Implemented	2,495		2,680		2,598		No	6/15/2022- 6/30/2023
Sheet Metal Workers Pension Plan of Southern CA, AZ, and NV	956052257-001	Yellow	Yellow	Implemented	2,615		3,255		2,119		No	6/30/2024
Southern California IBEW-NECA Pension Trust Fund	956392774-001	Yellow as of 6/30/2021	Yellow as of 6/30/2020	Implemented	2,746		1,714		1,477		No	6/30/2022- 5/31/2026
Western Conference of Teamsters Pension Plan	916145047-001	Green	Green	No	3,006		3,025		2,814		No	12/31/2023- 12/31/2025
Other funds					23,390		23,722		19,598
Total contributions					$	82,388	$	85,444	$	72,525

*Plan includes contributions required by collective bargaining agreements which have expired but contain provisions automatically renewing their terms in the absence of a subsequent negotiated agreement.

The Company was listed in the plans' Forms 5500 as providing more than 5 percent of the total contributions for the following plans and plan years:

Pension Fund	Year Contributions to Plan Exceeded More Than 5 Percent of Total Contributions (as of December 31 of the Plan's Year-End)
Edison Pension Plan	2020 and 2019
IBEW Local 82 Pension Plan	2020 and 2019
IBEW Local 124 Pension Trust Fund	2020 and 2019
IBEW Local 212 Pension Trust Fund	2020 and 2019
IBEW Local 357 Pension Plan A	2020 and 2019
IBEW Local 648 Pension Plan	2020 and 2019
IBEW Local 683 Pension Fund Pension Plan	2020 and 2019
IBEW Local Union No 226 Open End Pension Fund	2020 and 2019
Idaho Plumbers and Pipefitters Pension Plan	2020 and 2019
International Union of Operating Engineers Local 701 Pension Trust Fund	2020 and 2019
Minnesota Teamsters Construction Division Pension Fund	2020 and 2019
Pension and Retirement Plan of Plumbers and Pipefitters Local 525	2020 and 2019
Southwest Marine Pension Trust	2020 and 2019