Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Credit Facility - Schedule of Additional Detail on Credit Facility (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Debt Disclosure [Abstract]    
Outstanding balance $ 283,346 $ 247,350
Value of collateral pledged to credit facility $ 471,000 $ 356,000
Weighted average short-term borrowing rate 2.30% 2.30%