Stock-Based Compensation - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Time-based Restricted Units [Member]
Stock Based Compensation [Line Items]
Restricted units awarded to managers	10,992	13,545	25,280	33,593
Performance-based Restricted Units [Member]
Stock Based Compensation [Line Items]
Restricted units awarded to managers	2,318	765	310,481	152,331