Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Net Income
Net income		$ 57,156	$ 58,488	$ 53,935	$ 50,142	$ 55,201	$ 58,503	$ 51,417	$ 61,983	$ 219,721		$ 227,104		$ 180,533
Dividends on preferred stock		(8,797)	(5,729)	(5,729)	(5,728)	(5,728)	(5,729)	(5,659)	(3,757)	(25,983)		(20,873)		(14,473)
Net Income Allocated to Common Shareholders		$ 48,359	$ 52,759	$ 48,206	$ 44,414	$ 49,473	$ 52,774	$ 45,758	$ 58,226	$ 193,738		$ 206,231		$ 166,060
Weighted-Average Shares
Weighted average shares - Basic	[1]									43,164,477		43,172,078		43,113,741
Effect of dilutive securities-restricted stock awards										152,427		153,225		53,372
Weighted average shares - diluted	[1]									43,316,904		43,325,303		43,167,113
Per Share Amount
Basic earnings per share(1)		$ 1.12	$ 1.22	$ 1.12	$ 1.03	$ 1.15	$ 1.22	$ 1.06	$ 1.35	$ 4.49	[1]	$ 4.78	[1]	$ 3.85	[1]
Diluted earnings per share(1)		$ 1.12	$ 1.22	$ 1.11	$ 1.02	$ 1.14	$ 1.22	$ 1.06	$ 1.35	$ 4.47	[1]	$ 4.76	[1]	$ 3.85	[1]

[1] The number of shares and per share amounts have been restated to reflect the 3-for-2 common stock split, effective on January 17, 2022.