Basis of Presentation and Responsibility for Interim Financial Statements - Schedule of Effect of Adoption of ASU 2017-07 (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)
Selling, general and administrative expenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	$ 251.7
Selling, general and administrative expenses | Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	253.9
Selling, general and administrative expenses | Effect of Change | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	(2.2)
Operating income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	140.6
Operating income | Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	138.4
Operating income | Effect of Change | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	2.2
Other expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	2.2
Other expense | Previously Reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	0.0
Other expense | Effect of Change | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost	$ 2.2