SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 6) (Risk management contracts, Credit risk)	12 Months Ended
	Dec. 31, 2011 counterparty
Risk management contracts | Credit risk
Risk Management Activities
Minimum percentage of total credit risk exposure used to account for counterparties and industries	10.00%
Number of counterparty or industry that accounted for more than 10% of total credit risk exposure	0