SHORT-TERM BORROWINGS AND LONG-TERM DEBT (Details) (USD $) In Millions, unless otherwise specified		1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended
	Dec. 31, 2010	Jun. 30, 2011 2011 Credit Facility Y	Dec. 31, 2011 2011 Credit Facility	Dec. 31, 2011 2011 Credit Facility Lower limit	Dec. 31, 2011 2011 Credit Facility Upper limit	Feb. 28, 2009 2009 Credit Facility Y	Dec. 31, 2011 2009 Credit Facility	Dec. 31, 2010 2009 Credit Facility
Line of credit facility disclosures
Short-term borrowings	$ 1.2
Term of credit facility (in years)		5				3
Line of credit, maximum amount of outstanding borrowings and letters of credit permitted at any one time			500.0
Line of credit, potential maximum with Company request and lender consent			$ 750.0
Credit Facility covenant, consolidated total debt to consolidated EBITDA ratio, numerator					3.25
Credit Facility covenant, consolidated total debt to consolidated EBITDA ratio, denominator					1.0
Credit Facility covenant, consolidated EBITDA to consolidated interest expense ratio, numerator				3.0
Credit Facility covenant, consolidated EBITDA to consolidated interest expense ratio, denominator				1.0
Description of interest rate basis			LIBOR
Range of margin added to base rate (as a percent)				0.075%	1.45%
Credit facility, commitment fee percentage			0.20%
Credit facility weighted average interest rate (as a percent)			1.60%				1.60%	2.73%