Other Assets - Components of Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Total derivative instruments, Assets, Fair Value	$ 79,257	$ 68,151
Real estate owned, net	74,032	88,362
Deferred debt issuance costs	42,423	53,909
Margin receivable on derivative instruments	0	14,664
Other	36,705	55,708
Total other assets	$ 232,417	$ 280,794