Insurance Activity - Summary of Losses and Loss Adjustment Reserve Activity (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Insurance [Abstract]
Balance at beginning of period	$ 18,947	$ 44,314
Incurred (released) - prior periods	(318)	3,281
Paid - prior periods	(11,321)	(28,648)
Total losses and loss adjustment reserves	$ 7,308	$ 18,947