Potentially Dilutive Securities Not Included in Computation of Diluted Net Loss Per Share (Detail) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
SARs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	3,956,542		797,475		3,956,542		797,475
Anti Dilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Price	$ 7.82		$ 10.59		$ 7.82		$ 10.59
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				1,750
Anti Dilutive Securities Excluded from Computation of Earnings Per Share, Weighted Average Price	$ 6.91				$ 6.91
Restricted Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti dilutive Securities Excluded from Computation of Earnings Per Share, Shares	1,228,778	[1]	811,553	[1]	1,228,778	[1]	811,553	[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				29,250

[1] Anti-dilutive securities include contingently issuable shares unvested as of September 30, 2013 and 2012, the vesting of which is based on performance conditions and market conditions that have not yet been achieved. See Note 10, “Equity-Based Compensation.”