Fair Value Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted Cash and Cash Equivalents	$ 0.2	$ 15.3
Derivative Asset	8.2	12.4
Derivative Liability	0.4	0.3
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	129.6	278.8
Restricted Cash and Cash Equivalents	0.2	15.3
Investments, Fair Value Disclosure	9.7	8.4
Derivative Asset	8.2	12.4
Assets, Fair Value Disclosure, Recurring	147.7	314.9
Derivative Liability	0.4	0.3
Liabilities, Fair Value Disclosure, Recurring	0.4	0.3
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	110.2	155.6
Restricted Cash and Cash Equivalents	0.0	0.0
Investments, Fair Value Disclosure	0.0	0.0
Derivative Asset	0.0	0.0
Assets, Fair Value Disclosure, Recurring	110.2	155.6
Derivative Liability	0.0	0.0
Liabilities, Fair Value Disclosure, Recurring	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	19.4	123.2
Restricted Cash and Cash Equivalents	0.2	15.3
Investments, Fair Value Disclosure	9.7	8.4
Derivative Asset	8.2	12.4
Assets, Fair Value Disclosure, Recurring	37.5	159.3
Derivative Liability	0.4	0.3
Liabilities, Fair Value Disclosure, Recurring	0.4	0.3
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0.0	0.0
Restricted Cash and Cash Equivalents	0.0	0.0
Investments, Fair Value Disclosure	0.0	0.0
Derivative Asset	0.0	0.0
Assets, Fair Value Disclosure, Recurring	0.0	0.0
Derivative Liability	0.0	0.0
Liabilities, Fair Value Disclosure, Recurring	$ 0.0	$ 0.0