Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 1,259.6	$ 1,054.9	$ 2,452.5	$ 2,072.3
Distribution revenues
Disaggregation of Revenue [Line Items]
Revenues	401.5	343.8	768.4	675.0
Foreign currency exchange
Disaggregation of Revenue [Line Items]
Revenues	(4.3)	(6.4)	(5.5)	(14.9)
Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	797.6	672.6	1,548.5	1,322.2
Event-driven fee revenues
Disaggregation of Revenue [Line Items]
Revenues	64.7	44.9	141.1	90.0
Investor Communication Solutions
Disaggregation of Revenue [Line Items]
Revenues	893.3	776.0	1,746.8	1,521.5
Investor Communication Solutions | Regulatory
Disaggregation of Revenue [Line Items]
Revenues	166.4	144.7	331.8	279.5
Investor Communication Solutions | Data-driven fund solutions
Disaggregation of Revenue [Line Items]
Revenues	88.8	86.1	172.1	165.1
Investor Communication Solutions | Issuer
Disaggregation of Revenue [Line Items]
Revenues	23.7	20.8	44.2	38.5
Investor Communication Solutions | Customer communications
Disaggregation of Revenue [Line Items]
Revenues	148.2	135.8	289.1	273.4
Investor Communication Solutions | Total ICS Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	427.1	387.3	837.3	756.5
Investor Communication Solutions | Equity and other
Disaggregation of Revenue [Line Items]
Revenues	24.6	20.6	52.2	38.7
Investor Communication Solutions | Mutual funds
Disaggregation of Revenue [Line Items]
Revenues	40.1	24.3	88.9	51.4
Investor Communication Solutions | Total ICS Event-driven fee revenues
Disaggregation of Revenue [Line Items]
Revenues	64.7	44.9	141.1	90.0
Investor Communication Solutions | Distribution revenues
Disaggregation of Revenue [Line Items]
Revenues	401.5	343.8	768.4	675.0
Global Technology and Operations
Disaggregation of Revenue [Line Items]
Revenues	1,259.6	1,054.9	2,452.5	2,072.3
Global Technology and Operations | Capital markets
Disaggregation of Revenue [Line Items]
Revenues	224.1	158.4	433.5	314.7
Global Technology and Operations | Wealth and investment management
Disaggregation of Revenue [Line Items]
Revenues	146.4	126.9	277.7	251.0
Global Technology and Operations | Total GTO Recurring fee revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 370.6	$ 285.3	$ 711.2	$ 565.7