Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Change in carrying amount of goodwill	$ 0		$ 0
Amortization expense	$ 34,000	$ 34,000	$ 68,000	$ 67,000