Intangible Assets and Goodwill - Additional Information (Detail) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible assets and goodwill impairment	$ 0
Amortization expense		$ 51,000	$ 63,000	$ 69,000