Recently Issued Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Jun. 30, 2018	Apr. 01, 2018	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term deferred tax assets	$ 1,717.1		$ 1,656.5	$ 100.2
Long-term deferred tax liability	(830.5)		(221.5)	(205.8)
Other assets	(106.4)		(47.7)	(71.8)
Other long-term liabilities	$ (257.4)		$ (239.2)	(240.9)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Long-term deferred tax assets		$ 1,580.0		1,579.4
Long-term deferred tax liability		1.1		1.1
Other assets		24.1		24.1
Other long-term liabilities		$ 1.7		$ 1.7