Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Loans Managed, Securitized or Asset-backed Financing Arrangement [Abstract]
Interest expense on securitized debt obligations	$ 3.8	$ 3.8