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

Amount of total losses gains for period included in earnings attributable to assets still held

No definition available.

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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

+ 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

+ 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

+ 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

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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.

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