Consolidated Statements Of Equity - USD ($) $ in Thousands	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2020	$ 124,285	$ 3,379,057	$ 1,261,862	$ (81,327)	$ 4,683,877
Net income			183,689		183,689
Dividends declared and paid			(61,520)		(61,520)
Issuance of common stock under dividend reinvestment plan	49	4,112			4,161
Repurchase of stock				(3,262)	(3,262)
Equity compensation plan	97	(97)
Exercise of stock options	10	704			714
Stock-based compensation		2,631	(174)		2,457
Other		(31)		256	225
Balance at Mar. 31, 2021	124,441	3,386,376	1,383,857	(84,333)	4,810,341
Balance at Dec. 31, 2020	124,285	3,379,057	1,261,862	(81,327)	4,683,877
Net income					315,106
Balance at Sep. 30, 2021	127,990	3,698,095	1,385,631	(83,854)	5,127,862
Balance at Mar. 31, 2021	124,441	3,386,376	1,383,857	(84,333)	4,810,341
Net income			80,914		80,914
Dividends declared and paid			(61,584)		(61,584)
Issuance of common stock under dividend reinvestment plan	46	4,049			4,095
Repurchase of stock				(17)	(17)
Equity compensation plan	2	(2)
Exercise of stock options	11	781			792
Stock-based compensation		2,316	(146)		2,170
Other		(148)		252	104
Balance at Jun. 30, 2021	124,500	3,393,372	1,403,041	(84,098)	4,836,815
Net income			50,503		50,503
Dividends declared and paid			(67,758)		(67,758)
Issuance of common stock from stock purchase contracts	64	(64)
Issuance of common stock under dividend reinvestment plan	46	4,295			4,341
Issuance of common stock from forward equity sale agreement	3,350	296,389			299,739
Repurchase of stock				(8)	(8)
Equity compensation plan	2	(2)
Exercise of stock options	28	1,759			1,787
Stock-based compensation		2,328	(155)		2,173
Other		18		252	270
Balance at Sep. 30, 2021	127,990	3,698,095	1,385,631	(83,854)	5,127,862
Retained earnings					1,434,201
Balance at Dec. 31, 2021	128,050	3,705,814	1,434,201	(83,615)	5,184,450
Net income			199,376		199,376
Dividends declared and paid			(67,821)		(67,821)
Dividends declared			(67,863)		(67,863)
Issuance of common stock under dividend reinvestment plan	47	4,070			4,117
Repurchase of stock				(1,012)	(1,012)
Equity compensation plan	29	(29)
Exercise of stock options	14	998			1,012
Stock-based compensation		2,716	(136)		2,580
Other		(9)		270	261
Balance at Mar. 31, 2022	128,140	3,713,560	1,497,757	(84,357)	5,255,100
Balance at Dec. 31, 2021	128,050	3,705,814	1,434,201	(83,615)	5,184,450
Net income					350,305
Balance at Sep. 30, 2022	132,764	3,723,523	1,570,652	(83,837)	5,343,102
Balance at Mar. 31, 2022	128,140	3,713,560	1,497,757	(84,357)	5,255,100
Net income			82,291		82,291
Dividends declared and paid			(2,424)		(2,424)
Issuance of common stock from stock purchase contracts	4,515	(4,515)
Issuance of common stock under dividend reinvestment plan	47	4,007			4,054
Repurchase of stock				(15)	(15)
Equity compensation plan	2	(2)
Exercise of stock options	3	224			227
Stock-based compensation		2,725	(182)		2,543
Other		(24)		280	256
Balance at Jun. 30, 2022	132,707	3,715,975	1,577,442	(84,092)	5,342,032
Net income			68,638		68,638
Dividends declared and paid			(75,246)		(75,246)
Issuance of common stock under dividend reinvestment plan	44	4,206			4,250
Repurchase of stock				(29)	(29)
Equity compensation plan	3	(3)
Exercise of stock options	10	660			670
Stock-based compensation		2,702	(182)		2,520
Other		(17)		284	267
Balance at Sep. 30, 2022	$ 132,764	$ 3,723,523	$ 1,570,652	$ (83,837)	5,343,102
Retained earnings					$ 1,570,652