Restructuring Charges and Asset Impairment Charges - Activity and Reserve Balance for Restructuring Charges (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Reserve balance beginning of year			$ 0
Restructuring and asset impairment charges	$ 130,100,000	$ 2,300,000	68,500,000	$ 0	$ 0
Non-cash asset impairment charges			(56,400,000)	0	$ 0
Payments to be made from qualified pension plan associated with restructuring charges			(3,500,000)
Other items, net of cash payments			900,000
Reserve balance end of year	$ 9,500,000		$ 9,500,000	$ 0