Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 70,572,000		$ 70,572,000		$ 69,851,000
Goodwill impairment			0
Amortization expense related to intangible assets	$ 600,000	$ 600,000	$ 1,100,000	$ 1,100,000