Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Basic earnings per share:
Net income	$ 175,013	$ 150,021
Weighted average common shares outstanding - basic (in shares)	315,975	338,904
Basic earnings per share (in dollars per share)	$ 0.55	$ 0.44
Diluted earnings per share:
Net income	$ 175,013	$ 150,021
Diluted income available to common shareholders	$ 176,525	$ 153,733
Weighted average common shares outstanding - basic (in shares)	315,975	338,904
Effect of dilutive securities:
Weighted average common shares outstanding - diluted (in shares)	324,538	356,383
Diluted earnings per share (in dollars per share)	$ 0.54	$ 0.43
Federal statutory income tax rate (in hundredths)	21.00%	21.00%
9% Convertible Junior Subordinated Debentures
Diluted earnings per share:
Dilutive securities	$ 1,512	$ 3,712
Effect of dilutive securities:
Dilutive securities (in shares)	6,534	15,785
Stated interest rate	9.00%
Unvested RSUs
Effect of dilutive securities:
Unvested RSUs (in shares)	2,029	1,694