FEDERAL FUNDS PURCHASED (Details) (Federal funds purchased, USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Information on Federal funds purchased
Balance at end of year		$ 22,000	$ 22,000
Average balance outstanding during the year	3,496,000	871,000	2,379,000
Maximum balance outstanding at any month-end	100,000,000	6,023,000	3,022,000
Weighted average interest rate during the year (as a percent)	0.10%	0.20%	0.37%
Weighted average interest rate at end of year (as a percent)		0.15%	0.06%
Available borrowing capacity from Federal funds line facilities	$ 563,000,000	$ 313,000,000
Minimum
Information on Federal funds purchased
Maturity period	1
Maximum
Information on Federal funds purchased
Maturity period	6