Potentially Dilutive Securities Not Included in Computation of Diluted Net Loss Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	1,750		145		1,750		145
Anti Dilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Price	$ 6.91		$ 5.57		$ 6.91		$ 5.57
SARs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	4,177,416		4,405		4,177,416		4,405
Anti Dilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Price	$ 7.81		$ 7.80		$ 7.81		$ 7.80
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	1,237,354	[1]	1,274	[1]	1,237,354	[1]	1,274	[1]
DSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	29,250		41		29,250		41

[1] Anti-dilutive securities include contingently issuable shares unvested as of June 30, 2013, the vesting of which is based on performance conditions and market conditions that have not yet been achieved. See Note 9, “Equity-Based Compensation.”