CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Series E Preferred Stock	Impact of ASU 2016-13 adoption	Adjusted balance at January 1, 2020	Preferred Stock	Preferred Stock Adjusted balance at January 1, 2020	Common Stock	Common Stock Adjusted balance at January 1, 2020	Capital Surplus	Capital Surplus Adjusted balance at January 1, 2020	Retained Earnings	Retained Earnings Impact of ASU 2016-13 adoption	Retained Earnings Adjusted balance at January 1, 2020	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Adjusted balance at January 1, 2020
Balance at beginning of period at Dec. 31, 2019	$ 1,578,137		$ (14,891)	$ 1,563,246	$ 0	$ 0	$ 36,704	$ 36,704	$ 839,857	$ 839,857	$ 702,502	$ (14,891)	$ 687,611	$ (926)	$ (926)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	83,655										50,171			33,484
Cash dividends declared:
Common	(14,715)										(14,715)
Issuance of shares of Series E stock		$ 110,705
Issuance of shares of common stock	928						141		787
Stock based compensation	3,558								3,558
Balance at end of period at Jun. 30, 2020	1,747,377				110,705		36,845		844,202		723,067			32,558
Balance at beginning of period at Mar. 31, 2020	1,553,714				0		36,807		842,780		700,298			(26,171)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	88,860										30,131			58,729
Cash dividends declared:
Common	(7,362)										(7,362)
Issuance of shares of Series E stock	110,705				110,705
Issuance of shares of common stock	124						38		86
Stock based compensation	1,336								1,336
Balance at end of period at Jun. 30, 2020	1,747,377				$ 110,705		36,845		844,202		723,067			32,558
Cash dividends declared:
Shares of preferred stock issued (in shares)					11,500
Balance at beginning of period at Dec. 31, 2020	2,079,231				$ 110,705		42,094		1,062,083		791,630			72,719
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	98,287										114,419			(16,132)
Cash dividends declared:
Preferred	(4,025)										(4,025)
Common	(18,540)										(18,540)
Issuance of shares of common stock	57						151		(94)
Stock based compensation	4,776								4,776
Balance at end of period at Jun. 30, 2021	2,159,786				110,705		42,245		1,066,765		883,484			56,587
Balance at beginning of period at Mar. 31, 2021	2,056,207				110,705		42,174		1,063,497		833,171			6,660
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	111,532										61,605			49,927
Cash dividends declared:
Preferred	(2,012)										(2,012)
Common	(9,280)										(9,280)
Issuance of shares of common stock	1,323						71		1,252
Stock based compensation	2,016								2,016
Balance at end of period at Jun. 30, 2021	$ 2,159,786				$ 110,705		$ 42,245		$ 1,066,765		$ 883,484			$ 56,587