Recent Accounting Pronouncements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Jul. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Selling, general and administrative expense	$ (50.0)	$ (50.3)	$ (148.3)	$ (138.1)
Cost of sales	(486.7)	(476.2)	(1,416.9)	(1,272.3)
Other expense	$ (1.9)	0.5	$ (0.1)	0.7
Cumulative adjustment upon adoption of ASU 2017-12					$ 0.0
Operating lease, right-of-use asset, percentage of total assets (less than)	5.00%		5.00%
Operating lease, liability, percentage of total liabilities (less than)	5.00%		5.00%
Reinvested Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative adjustment upon adoption of ASU 2017-12					1.0
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Selling, general and administrative expense		0.5		1.5
Cost of sales			$ 0.1
Other expense		$ 0.5
Accounting Standards Update 2017-12 | Reinvested Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative adjustment upon adoption of ASU 2017-12					$ 1.0
Reclassified From Cost Of Goods Sold | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other expense				0.1
Reclassified From Selling, General And Administrative Expenses | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other expense				$ 1.5