Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Real estate owned, net	$ 104,554	$ 77,383
Derivative instruments	87,937	58,512
Investment in WCO	19,403	22,598
Deferred debt issuance costs	6,879	10,261
Other	23,517	31,610
Total other assets	$ 242,290	$ 200,364