CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance (in shares) at Dec. 31, 2015		91,428,274
Balance at Dec. 31, 2015	$ 545,504	$ 914	$ 679,916	$ (49,523)	$ (85,803)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of tax impact of share-based compensation (in shares)		338,017
Issuance of common stock, net of tax impact of share-based compensation	(1,761)	$ 4	(1,765)
Share-based compensation expense	1,756		1,756
Net income (loss)	39,201			39,201
Other comprehensive income (loss):
Cumulative translation adjustment	153				153
Pension and other postretirement benefit liability adjustment, net of tax	1,485				1,485
Balance (in shares) at Mar. 31, 2016		91,766,291.000
Balance at Mar. 31, 2016	$ 577,948	$ 918	671,517	(10,322)	(84,165)
Balance (in shares) at Dec. 31, 2016	90,586,741	90,586,741
Balance at Dec. 31, 2016	$ 610,556	$ 906	653,629	45,654	(89,633)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of tax impact of share-based compensation (in shares)		286,010
Issuance of common stock, net of tax impact of share-based compensation	(1,221)	$ 3	(1,224)
Share-based compensation expense	2,108		2,108
Net income (loss)	(9,759)			(9,759)
Dividends	(8,301)			(8,301)
Other comprehensive income (loss):
Cumulative translation adjustment	0
Pension and other postretirement benefit liability adjustment, net of tax	$ 1,644				1,644
Balance (in shares) at Mar. 31, 2017	90,872,751	90,872,751
Balance at Mar. 31, 2017	$ 595,027	$ 909	$ 654,513	$ 27,594	$ (87,989)