Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Aggregate intangible asset amortization expense	$ 1,305	$ 1,327	$ 1,515
Estimated intangible asset amortization expense in 2016	1,300
Estimated intangible asset amortization expense in 2017	1,300
Estimated intangible asset amortization expense in 2018	1,300
Estimated intangible asset amortization expense in 2019	1,300
Estimated intangible asset amortization expense in 2020	$ 1,200