Discontinued Operations - Assets and Liabilities Held-for-Sale (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Assets:
Total current assets held for sale	$ 146.2		$ 146.2		$ 220.5
Liabilities:
Total current liabilities	50.0		50.0		48.9
Digital Marketing Business | Discontinued Operations, Held-for-sale
Assets:
Accounts Receivable	108.5		108.5		121.9
Prepaid and other current assets	2.6		2.6		1.1
Total current assets held for sale	111.1		111.1		123.0
Property, plant and equipment, net	2.3		2.3		2.3
Goodwill	59.4		59.4		59.4
Intangible assets, net	39.7		39.7		35.6
Other assets	2.9		2.9		0.2
Total current assets held for sale	215.4		215.4		220.5
Liabilities:
Accounts payable	13.6		13.6		19.4
Deferred revenues	1.1		1.1		0.8
Accrued expenses and other current liabilities	34.9		34.9		26.0
Total current liabilities	49.6		49.6		46.2
Other liabilities	0.4		0.4		2.7
Total current liabilities held for sale	50.0		50.0		48.9
Net assets held for sale, at unadjusted carrying value(1)	165.4		165.4		171.6
Valuation allowance	(69.2)	$ 0.0	(69.2)	$ 0.0	0.0
Net assets held for sale, at fair value less selling costs	$ 96.2		$ 96.2		$ 171.6