Fair Value Measurements Fair Value and Related Carrying Amount of Certain Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 495.8	$ 1,160.1
Checks outstanding in excess of cash balances	12.8	54.7
Long-term debt	1,965.5	2,171.6
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, at Carrying Value	495.8	1,160.1
Checks outstanding in excess of cash balances	12.8	54.7
Long-term Debt	$ 2,218.5	$ 2,218.1