Commercial Mortgage Residual Interests Schedule of Key Assumptions Used in Determining the Value of the Residuals (Details)	9 Months Ended
	Sep. 30, 2016
Investment [Line Items]
Discount rate	20.00%
Loss severity of loans in foreclosure	20.00%
LIBOR	Forward 3-month curve
Prime	Forward curve
Minimum [Member]
Investment [Line Items]
Average life equivalent CPR speeds range	0.87%
Foreclosures frequency curve default model	0.00%
Maximum [Member]
Investment [Line Items]
Average life equivalent CPR speeds range	21.56%
Foreclosures frequency curve default model	1.33%