CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Total
Balances at Dec. 31, 2017		$ 2	$ 172,325	$ (6,122)	$ 397,640	$ 563,845
Balances, Shares at Dec. 31, 2017		20,391
Net income					17,138	17,138
Preferred stock dividends					(21)	(21)
Foreign currency translation adjustment				310		310
Issuance of common and preferred stock, net of offering costs	$ 40,000		956			40,956
Issuance of common and preferred stock, net of offering costs, Shares	1,600	100
Stock based compensation			592			592
Stock based compensation, Shares		2
Balances at Mar. 31, 2018	$ 40,000	$ 2	173,873	(5,812)	414,757	622,820
Balances, Shares at Mar. 31, 2018	1,600	20,493
Balances at Dec. 31, 2017		$ 2	172,325	(6,122)	397,640	563,845
Balances, Shares at Dec. 31, 2017		20,391
Net income						37,435
Preferred stock dividends						(1,169)
Foreign currency translation adjustment						(238)
Balances at Jun. 30, 2018	$ 54,990	$ 2	146,210	(6,360)	433,906	628,748
Balances, Shares at Jun. 30, 2018	2,200	19,306
Balances at Mar. 31, 2018	$ 40,000	$ 2	173,873	(5,812)	414,757	622,820
Balances, Shares at Mar. 31, 2018	1,600	20,493
Net income					20,297	20,297
Preferred stock dividends					(1,148)	(1,148)
Foreign currency translation adjustment				(548)		(548)
Issuance of common and preferred stock, net of offering costs	$ 14,990		(370)			14,620
Issuance of common and preferred stock, net of offering costs, Shares	600
Repurchase of common stock			(27,946)			(27,946)
Repurchase of common stock, Shares		(1,225)
Stock based compensation			653			653
Stock based compensation, Shares		38
Balances at Jun. 30, 2018	$ 54,990	$ 2	146,210	(6,360)	433,906	628,748
Balances, Shares at Jun. 30, 2018	2,200	19,306
Balances at Dec. 31, 2018	$ 103,865	$ 2	132,666	(6,513)	471,112	701,132
Balances, Shares at Dec. 31, 2018	4,155	18,764
Net income					18,574	18,574
Preferred stock dividends					(2,207)	(2,207)
Foreign currency translation adjustment				(81)		(81)
Repurchase of common stock			(13,946)			(13,946)
Repurchase of common stock, Shares		(595)
Stock based compensation			837			837
Stock based compensation, Shares		39
Balances at Mar. 31, 2019	$ 103,865	$ 2	119,557	(6,594)	487,479	704,309
Balances, Shares at Mar. 31, 2019	4,155	18,208
Balances at Dec. 31, 2018	$ 103,865	$ 2	132,666	(6,513)	471,112	701,132
Balances, Shares at Dec. 31, 2018	4,155	18,764
Net income						27,909
Preferred stock dividends						(4,414)
Foreign currency translation adjustment						(76)
Repurchase of common stock						$ (34,100)
Repurchase of common stock, Shares						(1,500)
Balances at Jun. 30, 2019	$ 103,865	$ 2	100,301	(6,589)	494,607	$ 692,186
Balances, Shares at Jun. 30, 2019	4,155	17,420
Balances at Mar. 31, 2019	$ 103,865	$ 2	119,557	(6,594)	487,479	704,309
Balances, Shares at Mar. 31, 2019	4,155	18,208
Net income					9,335	9,335
Preferred stock dividends					(2,207)	(2,207)
Foreign currency translation adjustment				5		5
Repurchase of common stock		$ (863)	(20,172)			(20,172)
Stock based compensation			916			916
Stock based compensation, Shares		75
Balances at Jun. 30, 2019	$ 103,865	$ 2	$ 100,301	$ (6,589)	$ 494,607	$ 692,186
Balances, Shares at Jun. 30, 2019	4,155	17,420