Derivative Financial Instruments (Schedule Of Derivative Financial Instruments On Statement Of Income) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) Recognized in Income, Net
Derivatives in fair value hedging relationships	$ (298)	$ 81	$ 86
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Total derivatives	(298)	81	86
Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net
Derivatives in fair value hedging relationships	(298)	81	86
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Total derivatives	(298)	81	86
Interest Income Expense [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) Recognized in Income, Net
Derivatives in fair value hedging relationships	(298)	81	86
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Total derivatives	(298)	81	86
Other Income [Member] | Interest Rate Contracts [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Derivative instruments not designated as hedging instruments, gain	1,450	1,782	3,654
Other Expense [Member] | Interest Rate Contracts [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Derivative instruments not designated as hedging instruments, loss	(1,450)	(1,782)	(3,654)
Other Income Expense [Member] | Interest Rate Contracts [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net
Derivative instruments not designated as hedging instruments, net	$ 0	$ 0	$ 0