Fair Value of Financial Instruments Significant Unobservable Inputs Level 3 (Details) (Fair Value, Inputs, Level 3 [Member])	3 Months Ended
	Jun. 30, 2013
Non-Agency CMBS [Member]
Fair Value Inputs, Quantitative Information [Abstract]
Fair Value Inputs, Prepayment Rate	20.00%
Fair Value Inputs, Probability of Default	2.50%
Fair Value Inputs, Loss Severity	35.00%
Fair Value Inputs, Discount Rate	6.10%
Non-Agency RMBS [Member]
Fair Value Inputs, Quantitative Information [Abstract]
Fair Value Inputs, Prepayment Rate	10.00%
Fair Value Inputs, Probability of Default	1.00%
Fair Value Inputs, Loss Severity	19.90%
Fair Value Inputs, Discount Rate	6.50%