Consolidated Statements of Changes in Shareholders' Equity - Unaudited - USD ($) $ in Thousands		Total	Preferred Stock	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance, preferred stock (shares) at Dec. 31, 2018			9,000,000
Beginning balance, common stock (shares) at Dec. 31, 2018				31,003,028
Beginning balance at Dec. 31, 2018		$ 956,816	$ 217,471	$ 32,252	$ 434,314	$ 316,651	$ (22,663)	$ (21,209)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		15,440				15,440
Other comprehensive income (loss)		7,744					7,744
Preferred stock dividends	[1]	(3,615)				(3,615)
Share-based compensation expense		2,109			2,109
Issuance of common stock under share-based compensation arrangements (shares)				159,378
Issuance of common stock under share-based compensation arrangements		450		$ 160	290
Repurchase of common shares (shares)				(31,159)
Repurchase of common shares		(571)						(571)
Ending balance, preferred stock (shares) at Mar. 31, 2019			9,000,000
Ending balance, common stock (shares) at Mar. 31, 2019				31,131,247
Ending balance at Mar. 31, 2019		$ 978,373	$ 217,471	$ 32,412	436,713	328,476	(14,919)	(21,780)
Beginning balance, preferred stock (shares) at Dec. 31, 2019		9,000,000	9,000,000
Beginning balance, common stock (shares) at Dec. 31, 2019		31,336,791		31,336,791
Beginning balance at Dec. 31, 2019		$ 1,052,795	$ 217,471	$ 32,617	444,218	381,519	(1,250)	(21,780)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		3,100				3,100
Other comprehensive income (loss)		(28,925)					(28,925)
Preferred stock dividends	[1]	(3,615)				(3,615)
Share-based compensation expense		3,228			3,228
Issuance of common stock under share-based compensation arrangements (shares)				133,235
Issuance of common stock under share-based compensation arrangements		$ (472)		$ 134	(606)
Ending balance, preferred stock (shares) at Mar. 31, 2020		9,000,000	9,000,000
Ending balance, common stock (shares) at Mar. 31, 2020		31,470,026		31,470,026
Ending balance at Mar. 31, 2020		$ 964,636	$ 217,471	$ 32,751	$ 446,840	$ 319,529	$ (30,175)	$ (21,780)

[1] Dividends per share of $0.4375, $0.40625, $0.403125, and $0.375 per share were declared on Series C, D, E, and F preferred stock for the three months ended March 31, 2020 and 2019, respectively.