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, 2018	$ 436,438	$ 591	$ 471,158	$ 56,051	$ (91,362)
Balance at (in shares) at Dec. 31, 2018		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 2016-02 [Member]	(71,358)			(71,358)
Amortization of stock awards and restricted stock	1,474		1,474
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
Balance at at Dec. 31, 2019	$ 460,342	$ 593	475,720	45,895	(61,866)
Balance at (in shares) at Dec. 31, 2019	59,329,431	59,329,431
Stock-based compensation plans
Grant of restricted stock	$ 0	$ 2	(2)
Grant of restricted stock (in shares)		200,500
Issuance of common shares, net of withholdings	(1,115)	$ 1	(1,116)
Withholdings of common shares, net of issuances (in shares)		93,264
Amortization of stock awards and restricted stock	1,821		1,821
Total comprehensive income (loss)	138,255			137,505	750
Balance at at Mar. 31, 2020	$ 599,303	$ 596	$ 476,423	$ 183,400	$ (61,116)
Balance at (in shares) at Mar. 31, 2020	59,623,195	59,623,195