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Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
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Dec. 31, 2011 M entity segment D component subsidiary | Dec. 31, 2010 | Dec. 31, 2009
Summary of Significant Accounting Policies |  |  |
Number of insurance-related subsidiaries | 2 |  |
Investment Securities |  |  |
Number of components in which other-than-temporary impairment is segregated | 2 |  |
Non-Accrual Loans |  |  |
Period of charge off for past due unsecured commercial loans (in days) | 90 |  |
Minimum period that past due unsecured loans outstanding may not be placed on nonaccrual status under special circumstances (in days) | 90 |  |
Maximum period of non-consumer loans outstanding that is used to evaluate whether loans should be placed on non-accrual status (in days) | 90 |  |
Other Real Estate Owned |  |  |
Other real estate owned | $ 86,626 | $ 87,192 |
Income Taxes |  |  |
Percentage of likelihood of realization of recognized tax benefit | 50.00% |  |
Consolidated Statements of Cash Flows |  |  |
Maximum term of maturity to classify short term investments as cash equivalents (in months) | 3 |  |
Segments of an Enterprise and Related Information |  |  |
Number of operating segments | 1 |  |
Number of active operating bank subsidiaries | 4 |  |
Reclassifications |  |  |
Decrease in cash provided by operating activities due to reclassification adjustment | 181,896 | 178,155 | 182,709
Increase in cash provided by investing activities due to reclassification adjustment | 206,060 | (255,443) | 638,210
Cash flow adjustment | Adjustment |  |  |
Reclassifications |  |  |
Decrease in cash provided by operating activities due to reclassification adjustment |  |  | (84,800)
Increase in cash provided by investing activities due to reclassification adjustment |  |  | $ 84,800

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- Definition Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings. + References No definition available. + Details
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