Schedule II. Condensed Financial Information of Registrant (Notes To Condensed Financial Statements) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements, Captions [Line Items]
Stock-based compensation not involving cash	$ 30,736	$ 35,650	$ 30,272
Interest paid	99,545	88,814	83,072
Income taxes paid (received)	$ 121,034	$ 114,888	96,218
Preferred stock, shares outstanding (in shares)	0	0
Parent Company
Condensed Financial Statements, Captions [Line Items]
Cash dividends from subsidiaries	$ 459,535	$ 407,042	478,535
Stock-based compensation not involving cash	30,736	35,650	30,272
Contribution of property to subsidiary	0	0	5,004
Interest paid	104,493	96,903	86,206
Income taxes paid (received)	$ (10,408)	$ (11,537)	$ (11,838)
Preferred stock, liquidation distribution available to stockholders, per share in thousands (in dollars per share)	$ 1,000
Preferred stock, liquidating distribution legally available, aggregate value	$ 351,000
Cumulative Series A Preferred Stock | Parent Company
Condensed Financial Statements, Captions [Line Items]
Preferred stock, shares issued (in shares)	351,000
Preferred stock, shares outstanding (in shares)	351,000
6.50% Cumulative Preferred Stock, Series A | Parent Company
Condensed Financial Statements, Captions [Line Items]
Preferred stock, shares issued (in shares)	280,000
Preferred stock, shares outstanding (in shares)	280,000
Preferred stock, dividend rate, percentage	6.50%
7.15% Cumulative Preferred Stock, Series A | Parent Company
Condensed Financial Statements, Captions [Line Items]
Preferred stock, shares issued (in shares)	71,000
Preferred stock, shares outstanding (in shares)	71,000
Preferred stock, dividend rate, percentage	7.15%