CONSOLIDATED STATEMENTS OF COMMON SHAREHOLDER’S EQUITY Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Subsidiaries [Member]	Subsidiaries [Member] Common Stock [Member]	Subsidiaries [Member] Additional Paid-in Capital [Member]	Subsidiaries [Member] Retained Earnings [Member]	Subsidiaries [Member] AOCI Attributable to Parent [Member]
Beginning Balance (in shares) at Dec. 31, 2021		200					85,903,791
Beginning Balance at Dec. 31, 2021	$ 4,563,316	$ 0	$ 3,523,532	$ 1,067,216	$ (27,432)	$ 4,355,430	$ 859	$ 3,485,105	$ 982,607	$ (113,141)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	278,295			278,295		288,081			288,081
Dividends, Common Stock	(939)			(939)		(13,896)			(13,896)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1,831				1,831	3,685				3,685
Ending Balance (in shares) at Mar. 31, 2022		200					85,903,791
Ending Balance at Mar. 31, 2022	$ 4,842,503	$ 0	3,523,532	1,344,572	(25,601)	$ 4,633,300	$ 859	3,485,105	1,256,792	(109,456)
Beginning Balance (in shares) at Dec. 31, 2022	200	200				85,903,791	85,903,791
Beginning Balance at Dec. 31, 2022	$ 4,964,089	$ 0	3,523,532	1,465,331	(24,774)	$ 4,871,083	$ 859	3,535,105	1,438,163	(103,044)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss) Attributable to Parent	(31)			(31)		27,535			27,535
Dividends, Common Stock	(28,133)			(28,133)		(28,002)			(28,002)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (658)				(658)	$ 133				133
Ending Balance (in shares) at Mar. 31, 2023	200	200				85,903,791	85,903,791
Ending Balance at Mar. 31, 2023	$ 4,935,267	$ 0	$ 3,523,532	$ 1,437,167	$ (25,432)	$ 4,870,749	$ 859	$ 3,535,105	$ 1,437,696	$ (102,911)