Fair Value Measurements (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets:
Restricted Cash		$ 2.7
Derivative, Asset	11.8	19.2
Total	11.8	21.9
Liabilities:
Derivative, Liability	0.3	1.9
Total	0.3	1.9
Fair Value, Inputs, Level 1 [Member]
Assets:
Restricted Cash		2.7
Derivative, Asset	5.7	2.2
Total	5.7	4.9
Liabilities:
Derivative, Liability	0	1.9
Total	0	1.9
Fair Value, Inputs, Level 2 [Member]
Assets:
Restricted Cash		0
Derivative, Asset	2.6	12.3
Total	2.6	12.3
Liabilities:
Derivative, Liability	0.3	0
Total	0.3	0
Fair Value, Inputs, Level 3 [Member]
Assets:
Restricted Cash		0
Derivative, Asset	3.5	4.7
Total	3.5	4.7
Liabilities:
Derivative, Liability	0	0
Total	$ 0	$ 0