Fair Value Disclosures (Assets Measured at Fair Value on a Nonrecurring Basis) (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	$ 73,649,000	$ 65,731,000
Foreclosed assets	17,760,000	26,245,000
Total Impaired loans and Foreclosed assets	91,409,000	91,976,000
Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	0	0
Foreclosed assets	0	0
Total Impaired loans and Foreclosed assets	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	0	0
Foreclosed assets	0	0
Total Impaired loans and Foreclosed assets	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans	73,649,000	65,731,000
Foreclosed assets	17,760,000	26,245,000
Total Impaired loans and Foreclosed assets	$ 91,409,000	$ 91,976,000