Equity-Based Compensation - Share Activity with Respect to Restricted Stock (Detail) - Restricted stock - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Issued and unvested, beginning of period (in shares)	3,480,828	3,755,275	1,185,071
Number of Shares, Granted (in shares)	555,680	581,672	3,239,948
Number of shares, Vested (in shares)	(766,159)	(785,820)	(299,703)
Number of Shares, Forfeited (in shares)	(626,319)	(70,299)	(370,041)
Number of Shares, Issued and unvested, end of period (in shares)	2,644,030	3,480,828	3,755,275
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Issued and unvested beginning balance (in dollars per share)	$ 15.82	$ 15.94	$ 9.52
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	8.37	15.48	17.22
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	17.96	18.20	11.76
Weighted Average Grant Fate Fair Value, Forfeited (in dollars per share)	10.90	17.35	9.96
Weighted Average Grant Date Fair Value, Issued and unvested ending balance (in dollars per share)	$ 14.15	$ 15.82	$ 15.94
Shares surrendered by employees for withholding taxes (in shares)	196,566	258,947	93,115