Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Changes in Benefit Obligation, Plan Assets and Funded Status for Pension and OPEB Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amounts recognized in the consolidated balance sheets [Abstract]
Noncurrent liabilities	$ (77,396)	$ (83,674)
Pension Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	(386,205)	(408,429)
Service cost	(6,805)	(8,182)	$ (8,932)
Interest cost	(10,646)	(10,533)	(12,263)
Actuarial gain	74,445	17,204
Benefits paid	17,708	23,735
Plan settlements	79,305	0
Benefit obligation at end of year	(232,198)	(386,205)	(408,429)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	329,796	325,790
Actual return on plan assets	(62,807)	22,597
Employer contributions and benefit payments	2,278	5,144
Benefits paid	(17,708)	(23,735)
Plan settlements	(79,313)	0
Fair value of plan assets at end of year	172,246	329,796	325,790
Amounts recognized in the consolidated balance sheets [Abstract]
Current liabilities	(2,517)	(2,462)
Noncurrent liabilities	(57,435)	(53,947)
Funded status	(59,952)	(56,409)
OPEB [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	(32,258)	(50,835)
Service cost	(316)	(670)	(508)
Interest cost	(914)	(1,267)	(1,502)
Actuarial gain	8,334	16,614
Benefits paid	2,784	3,900
Plan settlements	0	0
Benefit obligation at end of year	(22,370)	(32,258)	(50,835)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions and benefit payments	2,784	3,900
Benefits paid	(2,784)	(3,900)
Plan settlements	0	0
Fair value of plan assets at end of year	0	0	$ 0
Amounts recognized in the consolidated balance sheets [Abstract]
Current liabilities	(2,409)	(2,531)
Noncurrent liabilities	(19,961)	(29,727)
Funded status	$ (22,370)	$ (32,258)

Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.

Name:	us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.