CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands		Total		Common Stock	Additional Paid-In Capital		Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss
Balance at beginning of period (shares) at Dec. 31, 2014				94,080,840
Balance at beginning of period at Dec. 31, 2014		$ 627,318		$ 941	$ 752,375		$ (41,015)	$ (84,983)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of tax impact of share-based compensation (shares)				513,016
Issuance of common stock, net of tax impact of share-based compensation		(1,668)		$ 5	(1,673)
Share-based compensation expense		8,488			8,488
Share repurchases (shares)				(3,165,582)
Share repurchases		(53,010)		$ (32)	(52,978)
Net income (loss)		(8,508)					(8,508)
Dividends	[1]	(26,296)			(26,296)
Other comprehensive income (loss) (Note 13):
Change in fair value of derivative instruments, net of tax benefit		(87)						(87)
Cumulative translation adjustment		(1,333)						(1,333)
Pension and other postretirement benefit liability adjustment, net of tax benefit		600						600
Balance at end of period (shares) at Dec. 31, 2015				91,428,274.000
Balance at end of period 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 (shares)				529,652
Issuance of common stock, net of tax impact of share-based compensation		(1,748)		$ 6	(1,754)
Share-based compensation expense		$ 8,843			8,843
Share repurchases (shares)		(1,371,000)		(1,371,185)
Share repurchases		$ (25,000)		$ (14)	(24,986)
Net income (loss)		119,929					119,929
Dividends		(33,142)	[1]		(8,390)	[1]	(24,752)
Other comprehensive income (loss) (Note 13):
Change in fair value of derivative instruments, net of tax benefit		0
Cumulative translation adjustment		(2,257)						(2,257)
Pension and other postretirement benefit liability adjustment, net of tax benefit		$ (1,573)						(1,573)
Balance at end of period (shares) at Dec. 31, 2016		90,586,741		90,586,741
Balance at end of period 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 (shares)				537,018
Issuance of common stock, net of tax impact of share-based compensation		186		$ 5	181
Share-based compensation expense		5,417			5,417
Net income (loss)		61,588					61,588
Dividends	[1]	(33,023)			0		(33,023)
Other comprehensive income (loss) (Note 13):
Change in fair value of derivative instruments, net of tax benefit		0
Cumulative translation adjustment		0
Pension and other postretirement benefit liability adjustment, net of tax benefit		$ 11,223						11,223
Balance at end of period (shares) at Dec. 31, 2017		91,123,759		91,123,759
Balance at end of period at Dec. 31, 2017		$ 655,947		$ 911	$ 659,227		$ 74,219	$ (78,410)

[1] Cash dividends declared per common share were $0.36, $0.36 and $0.28 in the years ended December 31, 2017, 2016 and 2015, respectively.