Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Goodwill And Intangible Assets [Line Items]
Impairment charges			$ 0		$ 0
Amortization of intangible assets	$ 4,940,000	$ 5,404,000	14,820,000	$ 16,181,000
Favorable And Unfavorable Leases [Member]
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets	$ 97,000	$ 143,000	$ 292,000	$ 380,000