CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity adjustment for new ASU adoption	$ (1,713)				$ (1,713)
Balance at beginning of period at Dec. 31, 2018	1,325,175	$ 0	$ 34,477	$ 743,095	579,252	$ (31,649)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income/(loss)	51,542				31,497	20,045
Cash dividends declared:
Common	(5,530)				(5,530)
Issuance of shares of common stock	253		127	126
Stock based compensation	2,375			2,375
Balance at end of period at Mar. 31, 2019	1,372,102	0	34,604	745,596	603,506	(11,604)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity adjustment for new ASU adoption	(14,891)				(14,891)
Balance at beginning of period at Dec. 31, 2019	1,578,137	0	36,704	839,857	702,502	(926)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income/(loss)	(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)	$ 0