LONG-TERM DEBT (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2010
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 25,000,000	$ 25,000,000	$ 0
Amount Of New Mtn Program	200,000,000	200,000,000
Medium-term Notes [Member]
Debt Instrument [Line Items]
Proceeds from issuance of notes payable		60,000,000
Maturity Date		2026
Remaining balance available under note program	35,000,000	35,000,000
Maximum borrowing amount under loan program	$ 150,000,000	$ 150,000,000