Related Party Transactions - Additional Information (Detail) $ in Thousands		9 Months Ended
	Jun. 27, 2013 USD ($)	Sep. 30, 2015 USD ($) Directors
Oxbridge [Member]
Related Party Transaction [Line Items]
Number of non-employee directors | Directors		3
Moksha [Member]
Related Party Transaction [Line Items]
Number of non-employee directors | Directors		1
Payment for related party transaction	$ 4,300
Period from June 1, 2014 through May 31, 2015 [Member] | Oxbridge [Member]
Related Party Transaction [Line Items]
Assumed total covered exposure		$ 17,800
Transaction amount		4,935
Period from June 1, 2015 through May 31, 2016 [Member] | Oxbridge [Member]
Related Party Transaction [Line Items]
Assumed total covered exposure		11,600
Transaction amount		3,340
Period from June 1, 2013 through May 31, 2014 [Member] | Moksha [Member]
Related Party Transaction [Line Items]
Assumed total covered exposure		15,400
Transaction amount		$ 4,300