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Loss And Loss Adjustment Expense Reserves (RMBS Reserves) (Narrative) (Details) (USD $) | 0 Months Ended | 6 Months Ended | 9 Months Ended | 1 Months Ended | 9 Months Ended
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Aug. 31, 2011 | Mar. 31, 2012 | Sep. 30, 2011 | Sep. 30, 2011 Foreclosure [Member] | Sep. 30, 2011 Real Estate Owned [Member] | Sep. 30, 2011 Bankruptcy [Member] | Sep. 30, 2011 ALT-A [Member] RMBS And ALT-A [Member] | Sep. 30, 2011 RMBS [Member] | Aug. 31, 2011 RMBS And HELOC And CES [Member] | Sep. 30, 2011 RMBS And HELOC And CES [Member]
Loss And Loss Adjustment Expense Reserves [Line Items] |  |  |  |  |  |  |  |  |  |
Charged-off loan recovery value |  |  |  |  |  |  |  |  |  | $ 0
Delinquency period for fully charged-off loans, days |  |  |  |  |  |  |  | 90 |  |
Assumed roll rate for ninety plus day delinquent loans |  |  |  |  |  |  |  |  |  | 100.00%
Assumed roll rate for loans |  |  |  | 90.00% | 90.00% | 75.00% |  |  |  |
Period of elevated delinquency and loss, beginning, months |  |  |  |  |  |  |  |  |  | 6
Percentage of loans in 30-59 day delinquent bucket | 10.00% |  |  |  |  |  |  |  |  |
Percentage of loans charged off | 30.00% |  |  |  |  |  |  |  |  |
Percentage of current roll to loss for transaction | 3.00% |  |  |  |  |  |  |  |  |
Decrease in percentage of current roll to loss for transaction | 25.00% | 0.75% |  |  |  |  |  |  | 25.00% |
Current roll to loss by early 2014 |  |  | 0.00% |  |  |  |  |  |  |
Period of elevated delinquency and loss for stress case, additional months |  |  |  |  |  |  |  |  |  | 6
Increase to case basis reserves if losses remain at peak levels for six additional months |  |  |  |  |  |  |  |  |  | $ 110,000,000
Percentage of loss after declining over a 24 month period |  |  |  |  |  |  | 25.00% |  |  |

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- Definition Assumed Roll Rate For Loans + Details
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- Definition Assumed roll rate for ninety plus day delinquent loans. + Details
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- Definition Charged Off Loan Recovery Value + Details
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- Definition Decrease In Percentage Of Current Roll To Loss For Transaction + Details
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- Definition Delinquency period for fully charged off loans, days. + Details
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- Definition Loss And Loss Adjustment Expense Reserves [Line Items] + Details
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- Definition Percentage Of Current Roll To Loss For Transaction + Details
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- Definition Percentage Of Further Reduction Of Current Roll To Loss For Transaction + Details
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- Definition Percentage Of Loans Charged Off + Details
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- Definition Percentage Of Loans In 30-59 Day Delinquent Bucket + Details
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