Fair Value Measurements (Schedule Of Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3, beginning of period	$ 30,976	$ 50,628	$ 32,814	$ 61,098
Transfers out of Level 3	0	0	(975)	0
Change in unrealized loss included in other comprehensive income	1,587	(13,569)	2,279	(11,492)
Unrealized gain (loss) included in net income	(539)	(213)	(1,161)	(186)
Realized loss on sale of available for sale securities	0	0	0	(3,343)
Purchases/capital calls	0	179	126	411
Sales/proceeds	0	0	0	(5,487)
Accretion/amortization	63	213	79	488
Calls/paydowns	(2,219)	(2,746)	(3,294)	(6,759)
Other	0	0	0	(238)
Level 3, end of period	$ 29,868	$ 34,492	$ 29,868	$ 34,492