FAIR VALUE - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended		6 Months Ended
	Jun. 30, 2012	Sep. 30, 2012 Bonds	Dec. 31, 2011	Jun. 30, 2012 Medium term notes [Member]	Dec. 31, 2011 Medium term notes [Member]
Debt Instrument [Line Items]
Principal balance of medium-term notes			$ 15,400,000
Fair value of medium-term notes			23,342,000		16,000,000
Number of Bonds under collateralized debt obligation		125
Medium term notes carried rate	6.00%			6.00%
Net loss from fair value changes attributable to the Corporation's own credit to the medium-term notes		500,000
Principal value of debt	15,400,000			15,400,000
Maximum amount of interest in brokered CD sold by broker		$ 250,000