CREDIT FACILITIES (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum aggregate principal amount	$ 650
Amount outstanding under credit facility	0
Remaining availability for borrowings	387.2
Weighted-average interest rate (in hundredths)	2.25%	2.00%
Letter of Credit [Member]
Line of Credit Facility [Line Items]
Amount outstanding under credit facility	19.6
Maximum subfacility available under the credit facility	350
Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Maximum subfacility available under the credit facility	50
Trade Letters of Credit [Member]
Line of Credit Facility [Line Items]
Maximum subfacility available under the credit facility	350
Domestic Line of Credit [Member]
Line of Credit Facility [Line Items]
U.S. commitment drawable by U.S. borrowers as revolving loans or letters of credit	350
Line Of Credit Facility Maximum Availability For Letters Of Credit Under US Commitment Denominated In Alternative Currency	150
Foreign Line of Credit [Member]
Line of Credit Facility [Line Items]
International commitment drawable by U.S., Canadian, or European borrowers as revolving loans or letters of credit	$ 300