Summary of Significant Accounting Policies - Accounting Pronouncements (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax expense from remeasurement of deferred tax assets and liabilities related to Tax Cuts and Jobs Act		$ 64.6
Percentage of net sales accounted for using unit-of-delivery method		48.00%
Increase in operating income	$ 12.8	$ 114.3	$ 95.6	$ 36.1
Increase in nonoperating expense	(3.8)	(27.4)	(66.4)	$ (52.0)
Accounting Standards Update 2017-17 | Pro Forma
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase in operating income		73.2	68.9
Increase in nonoperating expense		$ 73.2	$ 68.9
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2015-17
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current deferred taxes reclassified as noncurrent	$ 36.5