Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net income	$ 96,275	$ 86,824	$ 74,262	$ 88,809	$ 91,007	$ 94,301	$ 257,360	$ 274,117
Preferred stock dividends	(2,875)			(4,155)			(8,625)	(14,236)
Net income available to common equity	93,400			84,655			248,735	259,880
Common shareholder dividends	(30,149)			(30,323)			(90,647)	(85,604)
Unvested share-based payment awards	(194)			(222)			(609)	(634)
Undistributed earnings	63,057			54,109			157,479	173,642
Undistributed earnings allocated to common shareholders	62,648			53,716			156,454	172,436
Undistributed earnings allocated to unvested share-based payment awards	409			393			1,025	1,206
Basic
Distributed earnings to common shareholders	30,149			30,323			90,647	85,604
Undistributed earnings allocated to common shareholders	62,648			53,716			156,454	172,436
Total common shareholders earnings, basic	92,796			84,039			247,102	258,040
Diluted
Distributed earnings to common shareholders	30,149			30,323			90,647	85,604
Undistributed earnings allocated to common shareholders	62,648			53,716			156,454	172,436
Total common shareholders earnings, diluted	$ 92,796			$ 84,039			$ 247,102	$ 258,040
Weighted average common shares outstanding	149,321			150,046			149,063	151,473
Effect of dilutive common stock awards	942			1,096			1,141	1,228
Diluted weighted average common shares outstanding	150,262			151,143			150,205	152,701
Basic earnings per common share	$ 0.62			$ 0.56			$ 1.66	$ 1.70
Diluted earnings per common share	$ 0.62			$ 0.56			$ 1.65	$ 1.69