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Fair Value Measurement (Summary Of Changes In Fair Value Of Level 3 Financial Assets And Financial Liabilities Held At Fair Value) (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2012 | Sep. 30, 2011 | Sep. 30, 2012 | Sep. 30, 2011
Municipal Securities [Member] |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |  |
Beginning Balance | $ 0 | $ 0 | $ 0 | $ 1,624
Realized gains (losses) included in earnings | 0 | 0 | 0 | 39
Purchase |  |  | 0 | 0
Sales |  |  | 0 | (1,663)
Settlements |  |  |  | 0
Ending Balance | 0 | 0 | 0 | 0
The amount of total gains (losses) for period included in earnings attributable to assets still held at September 30 | 0 | 0 | 0 | 0
Collateralized Debt Obligations [Member] |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |  |
Beginning Balance | 76,325 | 55,724 | 47,503 | 55,692
Realized gains (losses) included in earnings | 5,032 | (11,857) | 8,854 | (12,936)
Purchase |  |  | 25,000 | 0
Sales |  |  | 0 | 0
Settlements |  |  | 0 | 1,111
Ending Balance | 81,357 | 43,867 | 81,357 | 43,867
The amount of total gains (losses) for period included in earnings attributable to assets still held at September 30 | 5,032 | (11,857) | 8,854 | (11,825)
Partnership Interest in a Private Credit Fund [Member] |  |  |  |
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] |  |  |  |
Beginning Balance | 11,030 |  | 10,008 |
Realized gains (losses) included in earnings | (455) |  | 567 |
Purchase |  |  | 0 |
Sales |  |  | 0 |
Settlements |  |  | 0 |
Ending Balance | 10,575 |  | 10,575 |
The amount of total gains (losses) for period included in earnings attributable to assets still held at September 30 | $ (455) |  | $ 567 |

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- Definition Amount of total losses gains for period included in earnings attributable to assets still held + References No definition available. + Details
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- Definition Amount of gain (loss) recognized in earnings, arising from assets measured at fair value on a recurring basis using unobservable inputs (level 3). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Definition Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Definition Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Definition Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
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- Definition This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 157 -Paragraph 32 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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