Net Loss per Share - Potentially Dilutive Securities Not Included in Computation of Diluted Net Loss Per Share (Detail) - $ / shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
DSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the computation of diluted net loss per share (in shares)	39	90	39	90
Weighted Average Price per Share, anti-dilutive securities excluded from computation of earnings per share (in dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ 0.00
SARs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the computation of diluted net loss per share (in shares)	483	530	483	530
Weighted Average Price per Share, anti-dilutive securities excluded from computation of earnings per share (in dollars per share)	$ 10.62	$ 10.74	$ 10.62	$ 10.74
Restricted stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included in the computation of diluted net loss per share (in shares)	2,676	3,550	2,676	3,550
Weighted Average Price per Share, anti-dilutive securities excluded from computation of earnings per share (in dollars per share)	$ 0.00	$ 0.00	$ 0.00	$ 0.00