Net Income (Loss) per Share - Potentially Dilutive Securities Not Included in Computation of Diluted Net Loss Per Share (Detail) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
SARs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	542	915	542	915
Anti dilutive securities excluded from computation of earnings per share, weighted average price (usd per share)	$ 10.64	$ 9.09	$ 10.64	$ 9.09
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	3,586	3,812	3,586	3,812
DSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	90	23	90	23