Stock-based Compensation - Summary of Stock Option Activity (Parenthetical) (Detail) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
2006 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based options granted	563,450	116,000	225,750
2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based options granted	2,739,845	1,632,825	1,798,420
2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based options granted	515,000	450,000