Other Assets (Detail) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Other Assets [Abstract]
Other assets	[1]	$ 102,396	$ 156,278
Loan servicing assets, at fair value
Other Assets [Abstract]
Other assets		50,984	33,676
Prepaid expenses
Other Assets [Abstract]
Other assets		23,403	23,427
Accounts receivable
Other Assets [Abstract]
Other assets		10,365	10,005
Other investments
Other Assets [Abstract]
Other assets		8,739	10,268
Deferred financing costs
Other Assets [Abstract]
Other assets		3,132	2,952
Receivable from investors
Other Assets [Abstract]
Other assets		1,889	2,318
Servicer reserve receivable
Other Assets [Abstract]
Other assets		1,343	13,685
Insurance reimbursements receivable
Other Assets [Abstract]
Other assets		0	52,119
Other
Other Assets [Abstract]
Other assets		$ 2,541	$ 7,828

[1] Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.