Goodwill and Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, Beginning balance	$ 2,570	$ 0
Accumulated impairment losses, Beginning balance	0	0	$ 0
Goodwill, impairment losses, Beginning balance	2,570	0
Goodwill acquired during year	1,259	2,570
Impairment losses	0	0
Goodwill, Ending balance	3,829	2,570
Goodwill, impairment losses, Ending balance	$ 3,829	$ 2,570