Business Combinations - Consideration Paid and Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Summary of the aggregate consideration paid and the aggregate amounts of the assets acquired and liabilities assumed
Accounts receivable	$ 11.1	$ 3.9
Inventory	139.9	80.5
Other current assets	2.9	0.1
Property and equipment	21.8	16.4
Indefinite-lived intangibles	365.6	51.1
Other noncurrent assets	0.1	2.7
Current liabilities	(33.6)	(9.2)
Noncurrent liabilities	(1.9)	(4.7)
Total consideration	505.9	140.8
Consideration transferred through common stock issuance	(32.4)
Contingent consideration	(20.0)
Seller financed/assumed debt	(3.8)
Total cash used in acquisitions	$ 449.7	$ 140.8