Financial Data by Segment - Schedule of Financial Data Segment Reporting Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2020 USD ($) Segment	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments										2	2
Earnings (loss) before income taxes	$ 294.8	$ 210.5	$ 10.5	$ 63.8	$ 230.0	$ 223.6	$ 64.3	$ 89.3	$ 579.5			$ 607.3	$ 561.0
Revenues	1,361.9	$ 1,249.9	$ 968.7	$ 948.6	1,211.2	$ 1,224.8	$ 953.4	$ 972.8	4,529.0			4,362.2	4,329.9
Assets	4,889.8				3,880.7				4,889.8	$ 4,889.8	$ 4,889.8	3,880.7	3,304.7
Payments to Acquire Property, Plant, and Equipment									62.7			50.6	76.7
Depreciation and amortization									73.8			85.2	82.1
Amortization of acquired intangibles and purchased intellectual property									122.9			87.4	81.4
Amortization of other assets									102.6			87.4	48.5
Investor Communication Solutions
Segment Reporting Information [Line Items]
Revenues									3,491.3			3,468.3
Operating Segments | Investor Communication Solutions
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes									464.1			506.2	489.1
Revenues									3,491.3			3,468.3	3,449.3
Assets	2,484.4				2,155.6				2,484.4	2,484.4	2,484.4	2,155.6	2,072.2
Payments to Acquire Property, Plant, and Equipment									35.9			34.5	38.9
Depreciation and amortization									42.9			54.3	51.7
Amortization of acquired intangibles and purchased intellectual property									81.7			70.6	64.7
Amortization of other assets									30.9			36.4	12.3
Operating Segments | Investor Communication Solutions | Restatement Adjustment
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes												(2.2)	(5.5)
Revenues												(42.8)	(46.3)
Operating Segments | Global Technology and Operations
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes									245.0			212.5	204.8
Revenues									1,174.2			996.3	957.9
Assets	1,734.2				1,423.6				1,734.2	1,734.2	1,734.2	1,423.6	925.1
Payments to Acquire Property, Plant, and Equipment									5.3			6.5	29.0
Depreciation and amortization									12.0			11.9	11.3
Amortization of acquired intangibles and purchased intellectual property									39.7			16.3	16.7
Amortization of other assets									54.8			45.7	30.9
Operating Segments | Global Technology and Operations | Restatement Adjustment
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes												2.2	5.5
Revenues												42.8	46.3
Other
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes									(146.3)			(130.9)	(151.4)
Revenues									0.0			0.0	0.0
Assets	671.1				301.6				671.1	671.1	671.1	301.6	307.4
Payments to Acquire Property, Plant, and Equipment									21.6			9.6	8.8
Depreciation and amortization									18.9			19.0	19.1
Amortization of acquired intangibles and purchased intellectual property									1.5			0.5	0.0
Amortization of other assets									16.8			5.3	5.3
Foreign Currency Exchange
Segment Reporting Information [Line Items]
Earnings (loss) before income taxes									16.8			19.4	18.6
Revenues									(136.4)			(102.4)	(77.3)
Assets	$ 0.0				$ 0.0				0.0	$ 0.0	$ 0.0	0.0	0.0
Payments to Acquire Property, Plant, and Equipment									0.0			0.0	0.0
Depreciation and amortization									0.0			0.0	0.0
Amortization of acquired intangibles and purchased intellectual property									0.0			0.0	0.0
Amortization of other assets									$ 0.0			$ 0.0	$ 0.0