CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Common Stock Including Additional Paid in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance, beginning of the period at Dec. 31, 2015	$ 1,300,059		$ 1,261,174	$ 39,615	$ (730)
Balance, beginning of the period, shares at Dec. 31, 2015		34,242,255
Net income	85,385			85,385
Other comprehensive income (loss)	(2,725)				(2,725)
Accrual of dividends on common stock	(29,672)			(29,672)
Stock Repurchased and Retired During Period, Shares		1,145,250
Cash paid for repurchase of common stock	(50,772)		(50,772)
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	3,401		3,401
Issuance of unvested restricted common stock, net, shares		96,382
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	34
Balance, end of the period, shares at Dec. 31, 2016		33,193,387
Balance, end of the period at Dec. 31, 2016	1,305,710		1,213,837	95,328	(3,455)
Net income	60,776			60,776
Other comprehensive income (loss)	(786)				(786)
Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings	0			795	(795)
Accrual of dividends on common stock	(66,364)			(66,364)
Stock Repurchased and Retired During Period, Shares		545,166
Cash paid for repurchase of common stock	(31,045)		(31,045)
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	4,335		4,335
Issuance of unvested restricted common stock, net, shares		78,264
Balance, end of the period, shares at Dec. 31, 2017		32,726,485
Balance, end of the period at Dec. 31, 2017	1,272,626		1,187,127	90,535	(5,036)
Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Tax and Reclassification Adjustment	0			(28,204)	28,204
Net income	136,515			136,515
Other comprehensive income (loss)	(16,064)				(16,064)
Accrual of dividends on common stock	(64,791)			64,791
Stock Repurchased and Retired During Period, Shares		594,711
Cash paid for repurchase of common stock	(34,401)		(34,401)
Amortization of share-based compensation related to restricted stock grants, net of shares surrendered	5,001		5,001
Issuance of unvested restricted common stock, net, shares		(57,073)
Stock Issued During Period, Value, Acquisitions	179,709
Stock Issued During Period, Shares, Acquisitions		3,108,071
Balance, end of the period, shares at Dec. 31, 2018		35,182,772
Balance, end of the period at Dec. 31, 2018	$ 1,478,595		$ 1,337,436	$ 134,055	$ 7,104