Asset Impairment Charges - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Asset impairment charges	$ 10,216,000	$ 39,597,000	$ 10,481,000	$ 39,597,000
Book value of property	$ 1,600,000		1,600,000
Asset impairment charge			$ 265,000