Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at at Dec. 31, 2017	$ 395,279	$ 591	$ 471,456	$ (13,748)	$ (63,020)
Balance at (in shares) at Dec. 31, 2017		59,057,195
Stock-based compensation plans
Grant of restricted stock	0	$ 1	(1)
Grant of restricted stock (in shares)		101,400
Issuance of common shares, net of withholdings	(1,320)	$ 1	(1,321)
Withholdings of common shares, net of issuances (in shares)		78,917
Stock Repurchased and Retired During Period, Shares		(157,000)
Stock Repurchased and Retired During Period, Value	(3,580)	$ (2)	(3,578)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2014-09 [Member]	514			514
Amortization of stock awards and restricted stock	1,014		1,014
NET EARNINGS	15,878			15,878
Total comprehensive income (loss)	16,591
Other comprehensive income (loss), net of tax					713
Balance at at Mar. 31, 2018	408,498	$ 591	467,570	2,644	(62,307)
Balance at (in shares) at Mar. 31, 2018		59,080,512
Balance at at Dec. 31, 2018	$ 436,438	$ 591	471,158	56,051	(91,362)
Balance at (in shares) at Dec. 31, 2018	59,134,173	59,134,173
Stock-based compensation plans
Grant of restricted stock	$ 0	$ 2	(2)
Grant of restricted stock (in shares)		125,200
Issuance of common shares, net of withholdings	(1,384)	$ 1	(1,385)
Withholdings of common shares, net of issuances (in shares)		91,953
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification | Accounting Standards Update 2018-07 [Member]	(71,358)			(71,358)
Amortization of stock awards and restricted stock	1,474		1,474
NET EARNINGS	22,665
Total comprehensive income (loss)	25,644			22,665	2,979
Balance at at Mar. 31, 2019	$ 390,814	$ 594	$ 471,245	$ 7,358	$ (88,383)
Balance at (in shares) at Mar. 31, 2019	59,351,326	59,351,326