DEBT - SENIOR NOTES (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended		3 Months Ended	12 Months Ended				12 Months Ended		12 Months Ended
	Dec. 31, 2011	Oct. 28, 2010	Dec. 31, 2011 Senior notes due 2016 [Member]	Dec. 31, 2010 Senior notes due 2016 [Member]	Dec. 31, 2011 Senior notes due 2020 [Member]	Dec. 31, 2011 Senior notes due 2020 [Member]	Dec. 31, 2010 Senior notes due 2020 [Member]	Dec. 31, 2011 Combined Senior notes due 2016 and 2020 [Member]	Dec. 31, 2010 Combined Senior notes due 2016 and 2020 [Member]	Dec. 31, 2011 Senior notes due 2013 [Member]	Dec. 31, 2010 Senior notes due 2013 [Member]	Dec. 31, 2011 Senior notes due 2015 [Member]	Dec. 31, 2010 Senior notes due 2015 [Member]
Debt Instrument [Line Items]
Bridge term loan credit agreement, maximum borrowing capacity		$ 925.0
Debt offering closing date			November 19, 2010			November 19, 2010		November 19, 2010
Face amount			325.0	325.0	600.0	600.0	600.0	925.0	925.0
Interest rate (in hundredths)			3.125%	3.125%	4.625%	4.625%	4.625%			5.50%	5.50%	5.625%	5.625%
Maturity date	May 15, 2016		May 15, 2016	May 15, 2016	Nov. 15, 2020	Nov. 15, 2020	Nov. 15, 2020			Jan. 31, 2013		Feb. 01, 2015
Periodic payments, frequency										semi-annually		semi-annually
Net proceeds from debt offerings								$ 915.4
Remaining quarterly principal payments date range, start			May 15, 2011