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	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Municipal Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		$ 1,624
Realized gains (losses) included in earnings		39
Purchase		0
Sales		(1,663)
Settlements		0
Ending Balance		0
The amount of total gains (losses) for period included in earnings attributable to assets still held at December 31		0
Collateralized Debt Obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	47,503	55,692
Realized gains (losses) included in earnings	7,975	(9,300)
Purchase	25,000	0
Sales	(37,677)	0
Settlements	0	1,111
Ending Balance	42,801	47,503
The amount of total gains (losses) for period included in earnings attributable to assets still held at December 31	(3,017)	(8,189)
Partnership Interest in a Private Credit Fund [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	10,008	0
Realized gains (losses) included in earnings	1,298	8
Purchase	0	10,000
Sales	0	0
Settlements	0	0
Ending Balance	11,306	10,008
The amount of total gains (losses) for period included in earnings attributable to assets still held at December 31	$ 1,298	$ 8