Quarterly report pursuant to Section 13 or 15(d)

Liquidity - Additional Information (Detail)

Liquidity - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Oct. 31, 2011
Line of Credit Facility [Line Items]      
FHLB advances amount $ 3.0 $ 3.3  
Percent of borrowing from FHLB 15.00%    
Total borrowing capacity based on pledged collateral 317.5    
Borrowing capacity available based on pledged collateral 314.5    
Bank's FHLB borrowing 3.0    
Borrowing percentage of total assets 0.11%    
Carrying value for loans pledged by bank 90.8    
Borrowings 0    
Maximum borrowing capacity of line of credit     100.0
Parent [Member]
Line of Credit Facility [Line Items]      
Amount of accrued interest payable on junior subordinated debentures 12.2 9.8  
Liquid assets, including amounts deposits with the bank 30.2 31.7  
Subsidiaries [Member]
Line of Credit Facility [Line Items]      
Broker deposits 0    
Fed Discount Window [Member]
Line of Credit Facility [Line Items]      
Amount available from borrowing source $ 56.1