Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Impairment of Goodwill	$ 0	$ 0
Amortization of Intangible Assets, Total	$ 2,845,000	$ 2,816,000	$ 2,841,000