CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Reclassification to earnings tax	$ (123.7)	$ (249.4)	$ (126.6)
Ineffectiveness tax	0.7	(1.0)	1.6
Change in fair value of derivative instruments tax	16.3	85.1	338.4
Current period net gain (loss) tax	7.5	(4.9)	(2.7)
Amortization of prior service cost included in net periodic pension cost tax	$ 0.7	$ 0.7	$ 0.5