Equity - Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period (in shares)		57,724,000			57,724,000
Balance at beginning of period	$ 1,470,837	$ 1,430,312	$ 1,302,988	$ 1,322,394	$ 1,430,312	$ 1,322,394
Net income (loss)	40,377	69,690	9,447	(22,334)	$ 110,067	(12,887)
Issuance of common stock	52,933	1,507	96,499	17,384
Repurchase of common stock	(93)	(1,142)	(108)	0
Dividends paid on common stock	(16,172)	(16,164)	(14,571)	(14,456)
Adjustment for unrecoverable pension benefit plan costs		(13,663)
Amounts reclassified to earnings	298	297
Investment in business with noncontrolling interest	0	0	0	0
Distribution to noncontrolling interest	$ (489)		(288)
Balance at end of period (in shares)	58,825,000				58,825,000
Balance at end of period	$ 1,547,691	$ 1,470,837	$ 1,393,967	$ 1,302,988	$ 1,547,691	$ 1,393,967
Dividends paid on common stock (in dollars per share)	$ 0.2800	$ 0.2800	$ 0.2600	$ 0.2600
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period (in shares)	57,754,000	57,724,000	55,991,000	55,598,000	57,724,000	55,598,000
Balance at beginning of period	$ 578	$ 577	$ 560	$ 556	$ 577	$ 556
Issuance of common stock (in shares)	1,073,000	55,000	1,713,000	420,000
Issuance of common stock	$ 10	$ 1	$ 17	$ 4
Repurchase of common stock (in shares)	(2,000)	(25,000)	(2,000)	(27,000)
Balance at end of period (in shares)	58,825,000	57,754,000	57,702,000	55,991,000	58,825,000	57,702,000
Balance at end of period	$ 588	$ 578	$ 577	$ 560	$ 588	$ 577
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	876,894	876,583	777,605	760,336	876,583	760,336
Issuance of common stock	52,923	1,506	96,482	17,380
Repurchase of common stock	(93)	(1,142)	(108)
Investment in business with noncontrolling interest	(348)	(53)	(56)	(111)
Balance at end of period	929,376	876,894	873,923	777,605	929,376	873,923
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	603,326	549,573	520,031	556,698	549,573	556,698
Net income (loss)	40,551	69,917	9,556	(22,211)
Dividends paid on common stock	(16,172)	(16,164)	(14,571)	(14,456)
Balance at end of period	627,705	603,326	515,016	520,031	627,705	515,016
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	(13,366)	0			0
Adjustment for unrecoverable pension benefit plan costs		(13,663)
Amounts reclassified to earnings	298	297
Balance at end of period	(13,068)	(13,366)			(13,068)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	3,405	3,579	4,792	4,804	3,579	4,804
Net income (loss)	(174)	(227)	(109)	(123)
Investment in business with noncontrolling interest	348	53	56	111
Distribution to noncontrolling interest	(489)		(288)
Balance at end of period	$ 3,090	$ 3,405	$ 4,451	$ 4,792	$ 3,090	$ 4,451