Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid In Capital	Retained Deficit	Accumulated Other Comp. Loss
Beginning balance (in shares) at Dec. 31, 2017		30,219,000
Beginning balance at Dec. 31, 2017	$ 74,742	$ 304	$ (9,114)	$ 239,870	$ (115,083)	$ (41,235)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	673			673	0
Total comprehensive income	10,985				9,853	1,132
Ending balance (in shares) at Mar. 31, 2018		30,219,000
Ending balance at Mar. 31, 2018	86,400	$ 304	(9,114)	240,543	(105,230)	(40,103)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	844			844
Total comprehensive income	7,297				13,195	(5,898)
Ending balance (in shares) at Jun. 30, 2018		30,219,000
Ending balance at Jun. 30, 2018	94,541	$ 304	(9,114)	241,387	(92,035)	(46,001)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	780			780
Total comprehensive income	9,994				12,583	(2,589)
Ending balance (in shares) at Sep. 30, 2018		30,219,000
Ending balance at Sep. 30, 2018	$ 105,315	$ 304	(9,114)	242,167	(79,452)	(48,590)
Beginning balance (in shares) at Dec. 31, 2018	30,512,843	30,513,000
Beginning balance at Dec. 31, 2018	$ 115,038	$ 318	(10,245)	243,007	(70,571)	(47,471)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	761			761
Total comprehensive income	10,924				11,130	(206)
Ending balance (in shares) at Mar. 31, 2019		30,513,000
Ending balance at Mar. 31, 2019	$ 126,651	$ 318	(10,245)	243,768	(59,513)	(47,677)
Beginning balance (in shares) at Dec. 31, 2018	30,512,843	30,513,000
Beginning balance at Dec. 31, 2018	$ 115,038	$ 318	(10,245)	243,007	(70,571)	(47,471)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense (in shares)		68,000
Share-based compensation expense	2,201	$ 1		2,200
Total comprehensive income	$ 22,578				26,827	(4,249)
Ending balance (in shares) at Sep. 30, 2019	30,581,274	30,581,000
Ending balance at Sep. 30, 2019	$ 139,745	$ 319	(10,245)	245,207	(43,816)	(51,720)
Beginning balance (in shares) at Mar. 31, 2019		30,513,000
Beginning balance at Mar. 31, 2019	126,651	$ 318	(10,245)	243,768	(59,513)	(47,677)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense (in shares)		68,000
Share-based compensation expense	719	$ 1		718
Total comprehensive income	9,132				7,177	1,955
Ending balance (in shares) at Jun. 30, 2019		30,581,000
Ending balance at Jun. 30, 2019	136,502	$ 319	(10,245)	244,486	(52,336)	(45,722)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	721			721
Total comprehensive income	$ 2,522				8,520	(5,998)
Ending balance (in shares) at Sep. 30, 2019	30,581,274	30,581,000
Ending balance at Sep. 30, 2019	$ 139,745	$ 319	$ (10,245)	$ 245,207	$ (43,816)	$ (51,720)