Consolidated Statements of Shareholders' Equity Statement - 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	Preferred Stock Including Additional Paid in Capital	Preferred Stock Including Additional Paid in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption accounting standard 2019-05	$ 582,988	$ (548)	$ 582,440			$ 162,807	$ 162,807	$ 229	$ 229	$ 858,347	$ 858,347	$ 173,806	$ 173,806	$ (612,201)	$ (548)	$ (612,749)
Balance, Preferred shares outstanding (in shares) at Dec. 31, 2019				6,788,330	6,788,330
Balance, Common shares outstanding at Dec. 31, 2019								22,945,993	22,945,993
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares				4,460,000
Stock Redeemed or Called During Period, Shares				(4,000,000)
Restricted stock granted, net of amortization								67,511
Stock Repurchased During Period, Shares								(18,782)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation								(12,744)
Balance, Preferred shares outstanding (in shares) at Mar. 31, 2020				7,248,330
Balance, Common shares outstanding at Mar. 31, 2020								22,981,978
Balance at Dec. 31, 2019	582,988	(548)	582,440			162,807	162,807	$ 229	$ 229	858,347	858,347	173,806	173,806	(612,201)	(548)	(612,749)
Balance at Dec. 31, 2019	(582,988)	548	(582,440)			(162,807)	(162,807)	(229)	$ (229)	(858,347)	(858,347)	(173,806)	(173,806)	612,201	548	612,749
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	107,988					107,988
Stock Redeemed or Called During Period, Value	(100,000)					(96,086)
Preferred stock redemption charge														(3,914)
Restricted stock granted, net of amortization	307							1		306
Stock Repurchased During Period, Value	(206)							0		(206)
Adjustments for tax withholding on share-based compensation	(235)							0		(235)
Stock issuance costs	(9)									(9)
Net income	(98,479)													(98,479)
Dividends on preferred stock	(3,841)													(3,841)
Dividends on common stock	(10,330)													(10,330)
Other Comprehensive Income (Loss), Net of Tax	72,972											72,972
Balance at Mar. 31, 2020	550,607					174,709		$ 230		858,203		246,778		(729,313)
Balance, Preferred shares outstanding (in shares) at Dec. 31, 2019				6,788,330	6,788,330
Balance, Common shares outstanding at Dec. 31, 2019								22,945,993	22,945,993
Balance, Preferred shares outstanding (in shares) at Sep. 30, 2020				7,248,330
Balance, Common shares outstanding at Sep. 30, 2020								23,145,238
Balance at Dec. 31, 2019	582,988	(548)	582,440			162,807	162,807	$ 229	$ 229	858,347	858,347	173,806	173,806	(612,201)	(548)	(612,749)
Balance at Dec. 31, 2019	(582,988)	$ 548	$ (582,440)			(162,807)	$ (162,807)	(229)	$ (229)	(858,347)	$ (858,347)	(173,806)	$ (173,806)	612,201	$ 548	$ 612,749
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock redemption charge	(3,914)
Other Comprehensive Income (Loss), Net of Tax	(85,077)
Balance at Sep. 30, 2020	603,553					174,709		231		859,089		88,729		(519,205)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends	(10,346)
Cumulative effect of adoption accounting standard 2019-05	550,607					174,709		$ 230		858,203		246,778		(729,313)
Balance, Preferred shares outstanding (in shares) at Mar. 31, 2020				7,248,330
Balance, Common shares outstanding at Mar. 31, 2020								22,981,978
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock granted, net of amortization								172,782
Stock Repurchased During Period, Shares								(14,143)
Balance, Preferred shares outstanding (in shares) at Jun. 30, 2020				7,248,330
Balance, Common shares outstanding at Jun. 30, 2020								23,140,617
Balance at Mar. 31, 2020	550,607					174,709		$ 230		858,203		246,778		(729,313)
Balance at Mar. 31, 2020	(550,607)					(174,709)		(230)		(858,203)		(246,778)		729,313
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock granted, net of amortization	423							1		422
Stock Repurchased During Period, Value	(166)							0		(166)
Stock issuance costs	(8)									(8)
Net income	194,838													194,838
Dividends on preferred stock	(3,253)													(3,253)
Dividends on common stock	(9,925)													(9,925)
Other Comprehensive Income (Loss), Net of Tax	(165,047)											(165,047)
Balance at Jun. 30, 2020	567,469					174,709		231		858,451		81,731		(547,653)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption accounting standard 2019-05	567,469					174,709		$ 231		858,451		81,731		(547,653)
Stock issuance, shares								5,219
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation								(598)
Balance, Preferred shares outstanding (in shares) at Sep. 30, 2020				7,248,330
Balance, Common shares outstanding at Sep. 30, 2020								23,145,238
Balance at Jun. 30, 2020	(567,469)					(174,709)		$ (231)		(858,451)		(81,731)		547,653
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	85							0		85
Preferred stock redemption charge	0
Restricted stock granted, net of amortization	568									568
Adjustments for tax withholding on share-based compensation	(10)									(10)
Stock issuance costs	(5)									(5)
Net income	40,725													40,725
Dividends on preferred stock	(3,252)													(3,252)
Dividends on common stock	(9,025)													(9,025)
Other Comprehensive Income (Loss), Net of Tax	6,998											6,998
Balance at Sep. 30, 2020	603,553					174,709		231		859,089		88,729		(519,205)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends	(3,252)
Cumulative effect of adoption accounting standard 2019-05	603,553					174,709		231		859,089		88,729		(519,205)
Cumulative effect of adoption accounting standard 2019-05	$ 633,453					174,564		$ 237		869,495		80,261		(491,104)
Balance, Preferred shares outstanding (in shares) at Dec. 31, 2020	7,248,330			7,248,330
Balance, Common shares outstanding at Dec. 31, 2020	23,697,970							23,697,970
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares								7,187,500
Stock Redeemed or Called During Period, Shares				(2,788,330)
Restricted stock granted, net of amortization								16,722
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation								(22,623)
Balance, Preferred shares outstanding (in shares) at Mar. 31, 2021				4,460,000
Balance, Common shares outstanding at Mar. 31, 2021								30,879,569
Balance at Dec. 31, 2020	$ 633,453					174,564		$ 237		869,495		80,261		(491,104)
Balance at Dec. 31, 2020	(633,453)					(174,564)		(237)		(869,495)		(80,261)		491,104
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	128,150							72		128,078
Stock Redeemed or Called During Period, Value	(69,708)					(66,721)
Preferred stock redemption charge														(2,987)
Restricted stock granted, net of amortization	451							0		451
Adjustments for tax withholding on share-based compensation	(428)							0		(428)
Stock issuance costs	(270)									(270)
Net income	117,929													117,929
Dividends on preferred stock	(2,559)													(2,559)
Dividends on common stock	(10,586)													(10,586)
Other Comprehensive Income (Loss), Net of Tax	(65,156)											(65,156)
Balance at Mar. 31, 2021	$ 731,276					107,843		$ 309		997,326		15,105		(389,307)
Balance, Preferred shares outstanding (in shares) at Dec. 31, 2020	7,248,330			7,248,330
Balance, Common shares outstanding at Dec. 31, 2020	23,697,970							23,697,970
Balance, Preferred shares outstanding (in shares) at Sep. 30, 2021	4,460,000			4,460,000
Balance, Common shares outstanding at Sep. 30, 2021	35,935,306							35,935,306
Balance at Dec. 31, 2020	$ 633,453					174,564		$ 237		869,495		80,261		(491,104)
Balance at Dec. 31, 2020	(633,453)					(174,564)		(237)		(869,495)		(80,261)		491,104
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock redemption charge	(2,987)
Other Comprehensive Income (Loss), Net of Tax	(60,025)
Balance at Sep. 30, 2021	773,511					107,843		359		1,094,296		20,236		(449,223)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends	(6,405)
Cumulative effect of adoption accounting standard 2019-05	731,276					107,843		$ 309		997,326		15,105		(389,307)
Balance, Preferred shares outstanding (in shares) at Mar. 31, 2021				4,460,000
Balance, Common shares outstanding at Mar. 31, 2021								30,879,569
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares								3,463,708
Restricted stock granted, net of amortization								23,305
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation								(22,016)
Balance, Preferred shares outstanding (in shares) at Jun. 30, 2021				4,460,000
Balance, Common shares outstanding at Jun. 30, 2021								34,344,566
Balance at Mar. 31, 2021	731,276					107,843		$ 309		997,326		15,105		(389,307)
Balance at Mar. 31, 2021	(731,276)					(107,843)		(309)		(997,326)		(15,105)		389,307
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	68,302							34		68,268
Restricted stock granted, net of amortization	444							0		444
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	100									100
Adjustments for tax withholding on share-based compensation	(425)							0		(425)
Stock issuance costs	(43)									(43)
Net income	(43,759)													(43,759)
Dividends on preferred stock	(1,923)													(1,923)
Dividends on common stock	(12,613)													(12,613)
Other Comprehensive Income (Loss), Net of Tax	14,270											14,270
Balance at Jun. 30, 2021	755,629					107,843		343		1,065,670		29,375		(447,602)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption accounting standard 2019-05	$ 755,629					107,843		$ 343		1,065,670		29,375		(447,602)
Stock issuance, shares								1,590,740
Restricted stock granted, net of amortization								0
Balance, Preferred shares outstanding (in shares) at Sep. 30, 2021	4,460,000			4,460,000
Balance, Common shares outstanding at Sep. 30, 2021	35,935,306							35,935,306
Balance at Jun. 30, 2021	$ (755,629)					(107,843)		$ (343)		(1,065,670)		(29,375)		447,602
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	27,898							16		27,882
Preferred stock redemption charge	0
Restricted stock granted, net of amortization	460							0		460
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	300									300
Stock issuance costs	(16)									(16)
Net income	14,033
Dividends on common stock	(13,731)													(13,731)
Other Comprehensive Income (Loss), Net of Tax	(9,139)											(9,139)
Balance at Sep. 30, 2021	773,511					107,843		359		1,094,296		20,236		(449,223)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends	(1,923)
Cumulative effect of adoption accounting standard 2019-05	$ 773,511					$ 107,843		$ 359		$ 1,094,296		$ 20,236		$ (449,223)