Commercial Mortgage Residual Interests (Narrative And Schedule Of Key Assumptions Used In Determining The Value Of The Residuals) (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Percent acquired of the non-controlling interest in majority owned and controlled subsidiary		21.10%
Cost to acquire the non-controlling interest in majority owned and controlled subsidiary		$ 1,603,000
Number of securitizations		7
Discount rate	25.00%	25.00%
Loss severity of loans in foreclosure	20.00%	20.00%
LIBOR	Forward 3-month curve	Forward 3-month curve
Prime	Forward curve	Forward curve
Maximum [Member]
Average life equivalent CPR speeds range	20.77%	20.37%
Frequency curve default model	14.70%	15.00%
Minimum [Member]
Average life equivalent CPR speeds range	2.18%	4.35%
Frequency curve default model	0.20%	0.10%