Fair Value Measurements (Foreclosed Assets Remeasured And Reported At Fair Value) (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 and Nonrecurring Basis [Line Items]
Charge-offs recognized in the allowance for loan losses	$ 8,957	$ 19,966	$ 24,747	$ 47,690
Foreclosed Assets Remeasured At Initial Recognition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of foreclosed assets prior to remeasurement			6,627	20,396
Charge-offs recognized in the allowance for loan losses			(1,291)	(3,593)
Fair value			5,336	16,803
Foreclosed Assets Remeasured Subsequent To Initial Recognition [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of foreclosed assets prior to remeasurement			10,183	6,023
Write-downs included in other non-interest expense			(1,528)	(2,173)
Fair value			$ 8,655	$ 3,850