Annual report pursuant to Section 13 and 15(d)

Credit Facility - Schedule of Additional Detail on Credit Facility (Detail)

v3.3.1.900
Credit Facility - Schedule of Additional Detail on Credit Facility (Detail) - USD ($)
$ in Thousands
Dec. 31, 2015
Dec. 31, 2014
Debt Disclosure [Abstract]    
Outstanding balance $ 247,350 $ 315,748
Value of collateral pledged to credit facility $ 356,000 $ 422,000
Weighted average short-term borrowing rate 2.30% 2.40%