Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Basic earnings per share:
Net income	$ 191,054	$ 249,268	$ 345,601	$ 424,281
Weighted average common shares outstanding - basic (in shares)	285,906	308,840	288,434	312,388
Basic earnings per share (in dollars per share)	$ 0.67	$ 0.81	$ 1.20	$ 1.36
Diluted earnings per share:
Net income	$ 191,054	$ 249,268	$ 345,601	$ 424,281
Diluted income available to common shareholders	$ 191,429	$ 249,987	$ 346,351	$ 426,512
Weighted average common shares outstanding - basic (in shares)	285,906	308,840	288,434	312,388
Effect of dilutive securities:
Weighted average common shares outstanding - diluted (in shares)	289,566	313,545	292,125	319,012
Diluted earnings per share (in dollars per share)	$ 0.66	$ 0.80	$ 1.19	$ 1.34
Federal statutory income tax rate (in hundredths)	21.00%	21.00%	21.00%	21.00%
9% Convertible Junior Subordinated Debentures
Diluted earnings per share:
Dilutive securities	$ 375	$ 719	$ 750	$ 2,231
Effect of dilutive securities:
Dilutive securities (in shares)	1,644	3,092	1,644	4,803
Stated interest rate	9.00%		9.00%
Unvested RSUs
Effect of dilutive securities:
Unvested RSUs (in shares)	2,016	1,613	2,047	1,821