Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Basic earnings per share:
Net income	$ 249,268	$ 153,051	$ 424,281	$ 303,072
Weighted average common shares outstanding - basic (in shares)	308,840	339,326	312,388	339,116
Basic earnings per share (in dollars per share)	$ 0.81	$ 0.45	$ 1.36	$ 0.89
Diluted earnings per share:
Net income	$ 249,268	$ 153,051	$ 424,281	$ 303,072
Diluted income available to common shareholders	$ 249,987	$ 156,763	$ 426,512	$ 310,495
Weighted average common shares outstanding - basic (in shares)	308,840	339,326	312,388	339,116
Effect of dilutive securities:
Weighted average common shares outstanding - diluted (in shares)	313,545	356,536	319,012	356,461
Diluted earnings per share (in dollars per share)	$ 0.80	$ 0.44	$ 1.34	$ 0.87
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	$ 719	$ 3,712	$ 2,231	$ 7,423
Effect of dilutive securities:
Dilutive securities (in shares)	3,092	15,785	4,803	15,785
Stated interest rate	9.00%		9.00%
Unvested RSUs
Effect of dilutive securities:
Unvested RSUs (in shares)	1,613	1,425	1,821	1,560