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, 2024	Dec. 31, 2023	Dec. 31, 2022
Amounts recognized in the consolidated balance sheets [Abstract]
Noncurrent liabilities	$ (76,272)	$ (67,856)
Pension Plans [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	(233,202)	(232,198)
Service cost	(5,285)	(5,422)	$ (6,805)
Interest cost	(12,492)	(12,551)	(10,646)
Actuarial (loss) gain	(450)	86
Benefits paid	18,382	16,883
Benefit obligation at end of year	(233,047)	(233,202)	(232,198)
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	177,875	172,246
Actual return on plan assets	4,793	20,050
Employer contributions and benefit payments	6,436	2,462
Benefits paid	(18,382)	(16,883)
Fair value of plan assets at end of year	170,722	177,875	172,246
Amounts recognized in the consolidated balance sheets [Abstract]
Current liabilities	(2,630)	(2,586)
Noncurrent liabilities	(59,695)	(52,741)
Funded status	(62,325)	(55,327)
OPEB [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	(17,064)	(22,370)
Service cost	(93)	(110)	(316)
Interest cost	(877)	(1,175)	(914)
Actuarial (loss) gain	(3,140)	5,717
Benefits paid	2,129	874
Benefit obligation at end of year	(19,045)	(17,064)	(22,370)
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	2,129	874
Benefits paid	(2,129)	(874)
Fair value of plan assets at end of year	0	0	$ 0
Amounts recognized in the consolidated balance sheets [Abstract]
Current liabilities	(2,468)	(1,949)
Noncurrent liabilities	(16,577)	(15,115)
Funded status	$ (19,045)	$ (17,064)