Summary of Significant Accounting Policies - VIE & Fair Value (Details) $ in Millions	Dec. 31, 2016 USD ($)
Variable Interest Entities
REO assets as a percent of consolidated VIE assets	4.00%
Loans as a percent of consolidated VIE assets	96.00%
Fair Value Measurements
Permitted reinvestment under static investment in VIEs	$ 0.0