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Fair Value Measurements (Details 1) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2012 | Dec. 31, 2011
Corporate obligations [Member] |  |
Summary of weighted averages includes in significant inputs for the interest only strips valuation |  |
Coupon rate | 0.35% | 0.60%
Maturity | 21 years 10 months 21 days | 21 years 5 months 9 days
Yield | 0.68% | 7.20%
U.S. agency obligations [Member] |  |
Summary of weighted averages includes in significant inputs for the interest only strips valuation |  |
Coupon rate | 0.00% | 6.91%
Maturity | 0 years | 1 year 3 months 29 days
Yield | 0.00% | 2.13%
Collateralized debt obligations [Member] |  |
Summary of weighted averages includes in significant inputs for the interest only strips valuation |  |
Coupon rate | 1.13% | 0.86%
Maturity | 1 year 5 months 9 days | 1 year 6 months 18 days
Yield | 10.39% | 11.79%
Other asset-backed securities [Member] |  |
Summary of weighted averages includes in significant inputs for the interest only strips valuation |  |
Coupon rate | 0.87% | 1.41%
Maturity | 8 years 2 months 5 days | 3 years
Yield | 7.50% | 4.50%
European ABS transactions [Member] |  |
Summary of weighted averages includes in significant inputs for the interest only strips valuation |  |
Coupon rate | 1.59% | 1.56%
Maturity | 9 years 9 months 7 days | 11 years 11 months 27 days
Yield | 4.04% | 3.90%

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- Definition Fair value inputs coupon rate. + References No definition available. + Details
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- Definition Fair value inputs maturity. + References No definition available. + Details
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- Definition Fair value inputs yield. + References No definition available. + Details
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- Details
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