Estimated Fair Value Of Financial Instruments (Quantitative Information Regarding Level 3 Fair Value Measurements) (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Watch List Derivatives [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 1,199
Valuation Technique(s)	Discounted cash flow
Unobservable Input	Loss factors
Fair value measurement weighted average percentage	6.70%
Risk Participation Agreements [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	(1,177)	[1]
Valuation Technique(s)	Discounted cash flow
Unobservable Input	Loss factors
Fair value measurement weighted average percentage	0.50%
Collateral-Dependent Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	83,980
Valuation Technique(s)	Sales comparison, income capitalization and/or cost approach
Unobservable Input	Property specific adjustment
Fair value measurement weighted average percentage	15.10%
Warrants [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	19
Valuation Technique(s)	Option pricing model
Unobservable Input	Expected volatility
OREO [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value	$ 57,431
Valuation Technique(s)	Sales comparison, income capitalization and/or cost approach
Unobservable Input	Property specific adjustment
Fair value measurement weighted average percentage	11.90%
Expected Volatility [Member] | Warrants [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurement weighted average percentage	120.30%
Minimum [Member] | Watch List Derivatives [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	3.70%
Minimum [Member] | Risk Participation Agreements [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	0.00%
Minimum [Member] | Collateral-Dependent Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	10.00%
Minimum [Member] | OREO [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	0.80%
Minimum [Member] | Expected Term [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected term	1 year
Minimum [Member] | Expected Volatility [Member] | Warrants [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	99.80%
Maximum [Member] | Watch List Derivatives [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	15.80%
Maximum [Member] | Risk Participation Agreements [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	2.41%
Maximum [Member] | Collateral-Dependent Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	24.90%
Maximum [Member] | OREO [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	150.00%
Maximum [Member] | Expected Term [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected term	6 years
Maximum [Member] | Expected Volatility [Member] | Warrants [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurements range percentage	137.80%
Weighted Average [Member] | Property Specific Adjustment [Member] | Collateral-Dependent Impaired Loans [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurement weighted average percentage	15.10%	[2]
Weighted Average [Member] | Property Specific Adjustment [Member] | OREO [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurement weighted average percentage	11.90%	[2]
Weighted Average [Member] | Expected Term [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected term	2 years 6 months
Weighted Average [Member] | Expected Volatility [Member] | Property Specific Adjustment [Member] | Warrants [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value measurement weighted average percentage	120.30%

[1] Represents fair value of underlying swap.

[2] Weighted average is calculated based on assets with a property specific adjustment.