XML 67 R54.htm IDEA: XBRL DOCUMENT v3.8.0.1
Debt Obligations - Information on Borrowings under Current and Prior Credit Facility and Applicable Interest Rates (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Debt Disclosure [Abstract]        
Maximum amount outstanding under the credit facility during the period $ 917,895 $ 518,556 $ 917,895 $ 518,607
Average daily amount outstanding under the credit facility $ 760,418 $ 469,276 $ 564,178 $ 455,267
Weighted-average interest rate 2.66% 2.16% 2.60% 2.11%