CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Capital Surplus	Capital Surplus Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance
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	(5,205)									20,040			(25,245)
Cash dividends declared:
Common	(7,353)									(7,353)
Issuance of shares of common stock	804					103		701
Stock based compensation	2,222							2,222
Balance at end of period at Mar. 31, 2020	1,553,714			0		36,807		842,780		700,298			(26,171)
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	(13,245)									52,814			(66,059)
Cash dividends declared:
Preferred	(2,013)									(2,013)
Common	(9,260)									(9,260)
Issuance of shares of common stock	(1,266)					80		(1,346)
Stock based compensation	2,760							2,760
Balance at end of period at Mar. 31, 2021	$ 2,056,207			$ 110,705		$ 42,174		$ 1,063,497		$ 833,171			$ 6,660