Insurance Activity - Schedule of Premiums Assumed and Earned (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Insurance [Abstract]
Premiums assumed	$ 739	$ 1,166	$ 1,963	$ 3,680
Change in unearned premiums	47	81	463	258
Premiums earned	$ 786	$ 1,247	$ 2,426	$ 3,938