DEBT (Details) (USD $)						3 Months Ended					3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Sep. 30, 2007	Dec. 31, 2011 Revolving credit facility Years	Oct. 31, 2011 Revolving credit facility	Dec. 31, 2011 Revolving credit facility Minimum [Member]	Dec. 31, 2011 Revolving credit facility Maximum [Member]	Dec. 31, 2011 Revolving credit facility Rate 2C [Member] Minimum [Member]	Dec. 31, 2011 Revolving credit facility Rate 2C [Member] Maximum [Member]	Sep. 30, 2007 2007 Revolving credit facility Years	Dec. 31, 2011 2007 Revolving credit facility Minimum [Member]	Dec. 31, 2011 2007 Revolving credit facility Maximum [Member]	Dec. 31, 2011 LIBOR Revolving credit facility Rate 1 [Member] Minimum [Member]	Dec. 31, 2011 LIBOR Revolving credit facility Rate 1 [Member] Maximum [Member]	Dec. 31, 2011 LIBOR Revolving credit facility Rate 2C [Member]	Dec. 31, 2011 Federal funds rate Revolving credit facility Rate 2B [Member]
Debt Instrument
Debt Instrument, Basis Spread on Variable Rate															1.00%	0.50%
Debt Instrument, Applicable Margin Over Variable Rate								0.00%	0.50%				1.00%	1.50%
Revolving credit facility					$ 1,000,000,000
Period of revolving credit facility (in years)				5						5
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage						0.10%	0.25%				0.25%	0.375%
Letters of credit, maximum amount issuable under credit facility			50,000,000	100,000,000
Line of Credit Facility Revolving Credit, Maximum Amount of Swingline Loans to be Issued				50,000,000
Letters of Credit Outstanding, Amount	1,900,000	1,600,000
Line of Credit Facility, Terminated Amount			$ 175,000,000