DEBT AND CREDIT AGREEMENTS (Details 2) (Revolving Credit Facility, USD $)			9 Months Ended
	Sep. 30, 2012	May 31, 2012	Sep. 30, 2012 Eurodollar Loans	Sep. 30, 2012 ABR Loans	Sep. 30, 2012 Less than 25 percent Eurodollar Loans	Sep. 30, 2012 Less than 25 percent ABR Loans	Sep. 30, 2012 Greater than equal to 25 percent but less than 50 percent Eurodollar Loans	Sep. 30, 2012 Greater than equal to 25 percent but less than 50 percent ABR Loans	Sep. 30, 2012 Greater than equal to 50 percent but less than 75 percent Eurodollar Loans	Sep. 30, 2012 Greater than equal to 50 percent but less than 75 percent ABR Loans	Sep. 30, 2012 Greater than equal to 75 percent but less than 90 percent Eurodollar Loans	Sep. 30, 2012 Greater than equal to 75 percent but less than 90 percent ABR Loans	Sep. 30, 2012 Greater than and equal to 90 percent Eurodollar Loans	Sep. 30, 2012 Greater than and equal to 90 percent ABR Loans
Debt
Maximum borrowing capacity	$ 1,700,000,000
Available line of credit		900,000,000
Contingent increase of maximum borrowing capacity		500,000,000
Description of variable rate basis			Euro-Dollars (LIBOR)	Base Rate (Prime)
Capitalized debt issuance costs	5,000,000
Unamortized debt issuance costs associated with the original credit facility	1,300,000
Remaining unamortized costs under amended credit facility	$ 11,000,000
Margin (as a percent)					1.50%	0.50%	1.75%	0.75%	2.00%	1.00%	2.25%	1.25%	2.50%	1.50%