Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Earnings Per Share [Abstract]
Net income	$ 87,154	$ 103,360	$ 86,824	$ 74,262	$ 190,514	$ 161,086
Preferred stock dividends	(2,875)		(2,875)		(5,750)	(5,750)
Net income available to common equity	84,279		83,949		184,764	155,336
Common shareholder dividends	(31,802)		(30,126)		(63,611)	(60,499)
Unvested share-based payment awards	(194)		(205)		(398)	(415)
Undistributed earnings	52,283		53,618		120,755	94,422
Undistributed earnings allocated to common shareholders	51,965		53,257		120,047	93,807
Undistributed earnings allocated to unvested share-based payment awards	318		361		708	615
Basic
Distributed earnings to common shareholders	31,802		30,126		63,611	60,499
Undistributed earnings allocated to common shareholders	51,965		53,257		120,047	93,807
Total common shareholders earnings, basic	83,768		83,383		183,658	154,306
Diluted
Distributed earnings to common shareholders	31,802		30,126		63,611	60,499
Undistributed earnings allocated to common shareholders	51,965		53,257		120,047	93,807
Total common shareholders earnings, diluted	$ 83,768		$ 83,383		$ 183,658	$ 154,306
Weighted average common shares outstanding	149,986		149,083		149,875	148,933
Effect of dilutive common stock awards	884		1,121		1,027	1,332
Diluted weighted average common shares outstanding	150,870		150,203		150,903	150,265
Basic earnings per common share	$ 0.56		$ 0.56		$ 1.23	$ 1.04
Diluted earnings per common share	$ 0.56		$ 0.56		$ 1.22	$ 1.03