CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Treasury Stock	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2017	$ 271,953	$ 40	$ 349,243	$ (49,148)	$ (28,182)
Comprehensive income (loss)	70,276			70,276
Exercise of stock options	1,521		1,521
Tax withholding for share-based compensation	(2,083)		(2,083)
Share-based employee compensation expense	4,913		4,913
Balance at Sep. 30, 2018	346,580	40	353,594	21,128	(28,182)
Balance at Jun. 30, 2018	319,859	40	352,230	(4,229)	(28,182)
Comprehensive income (loss)	25,357			25,357
Exercise of stock options	385		385
Tax withholding for share-based compensation	(684)		(684)
Share-based employee compensation expense	1,663		1,663
Balance at Sep. 30, 2018	346,580	40	353,594	21,128	(28,182)
Balance at Dec. 31, 2018	369,001	41	347,487	49,655	(28,182)
Comprehensive income (loss)	20,196			36,271		$ (16,075)
Issuance of Common Stock in connection with Merger	132,838	6	132,832
Share-based compensation replacement awards related to Merger and attributable to pre-combination services	9,107		9,107
Exercise of stock options	701	1	700
Tax withholding for share-based compensation	(1,464)		(1,464)
Share-based employee compensation expense	15,266		15,266
Other	(247)		(129)	(118)
Balance at Sep. 30, 2019	545,398	48	503,799	85,808	(28,182)	(16,075)
Balance at Jun. 30, 2019	529,306	47	497,789	71,888	(28,182)	(12,236)
Comprehensive income (loss)	10,081			13,920		(3,839)
Exercise of stock options	330	1	329
Tax withholding for share-based compensation	(328)		(328)
Share-based employee compensation expense	6,009		6,009
Balance at Sep. 30, 2019	$ 545,398	$ 48	$ 503,799	$ 85,808	$ (28,182)	$ (16,075)