Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 1,389.8	$ 1,249.9	$ 3,462.1	$ 3,167.1
Distribution revenues
Disaggregation of Revenue [Line Items]
Revenues	449.1	412.1	1,126.0	1,042.4
Foreign currency exchange
Disaggregation of Revenue [Line Items]
Revenues	33.1	35.8	95.8	91.6
Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	900.0	834.5	2,267.5	2,106.1
Event-driven fee revenues
Disaggregation of Revenue [Line Items]
Revenues	73.8	39.1	164.5	110.3
Investor Communication Solutions
Disaggregation of Revenue [Line Items]
Revenues	1,109.3	980.2	2,646.0	2,398.4
Investor Communication Solutions | Regulatory
Disaggregation of Revenue [Line Items]
Revenues	289.6	241.5	572.9	492.2
Investor Communication Solutions | Data-driven fund solutions
Disaggregation of Revenue [Line Items]
Revenues	89.6	88.9	261.2	249.3
Investor Communication Solutions | Issuer
Disaggregation of Revenue [Line Items]
Revenues	44.3	34.6	82.8	68.1
Investor Communication Solutions | Customer communications
Disaggregation of Revenue [Line Items]
Revenues	163.0	164.0	438.7	436.1
Investor Communication Solutions | Total ICS Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	586.5	529.0	1,355.6	1,245.8
Investor Communication Solutions | Equity and other
Disaggregation of Revenue [Line Items]
Revenues	40.4	22.1	79.5	54.9
Investor Communication Solutions | Mutual funds
Disaggregation of Revenue [Line Items]
Revenues	33.4	17.0	85.0	55.3
Investor Communication Solutions | Total ICS Event-driven fee revenues
Disaggregation of Revenue [Line Items]
Revenues	73.8	39.1	164.5	110.3
Investor Communication Solutions | Distribution revenues
Disaggregation of Revenue [Line Items]
Revenues	449.1	412.1	1,126.0	1,042.4
Global Technology and Operations
Disaggregation of Revenue [Line Items]
Revenues	1,389.8	1,249.9	3,462.1	3,167.1
Global Technology and Operations | Capital markets
Disaggregation of Revenue [Line Items]
Revenues	167.3	169.2	499.4	479.5
Global Technology and Operations | Wealth and investment management
Disaggregation of Revenue [Line Items]
Revenues	146.2	136.2	412.4	380.8
Global Technology and Operations | Total GTO Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	313.5	305.5	911.9	860.3
Global Technology and Operations | Foreign currency exchange
Disaggregation of Revenue [Line Items]
Revenues	$ 33.1	$ 35.8	$ 95.8	$ 91.6