Acquisitions - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018	Feb. 28, 2018
Business Acquisition [Line Items]
Cash payment to acquire intellectual property		$ 0.0	$ 0.0	$ 40.0
Purchase price, net of cash acquired		339.1	354.7	108.3
Intellectual property purchase price					$ 40.0
Shadow Financial
Business Acquisition [Line Items]
Purchase price, net of cash acquired		$ 35.6
Shadow Financial | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Shadow Financial | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
Fi360
Business Acquisition [Line Items]
Purchase price, net of cash acquired		$ 116.0
Fi360 | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Fi360 | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
Clear-Structure
Business Acquisition [Line Items]
Contingent consideration maximum potential pay out		$ 12.5
Acquisition date fair value of contingent consideration liability		7.0
Purchase price, net of cash acquired		$ 59.1
Clear-Structure | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Clear-Structure | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
Funds-Library
Business Acquisition [Line Items]
Purchase price, net of cash acquired		$ 69.6
Funds-Library | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Funds-Library | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		3 years
Rockall
Business Acquisition [Line Items]
Contingent consideration maximum potential pay out		$ 10.1
Settlement of deferred payment obligation	$ 0.5
Acquisition date fair value of contingent consideration liability		$ 7.6
Purchase price, net of cash acquired			34.9
Rockall | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		6 years
Rockall | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		4 years
RPM
Business Acquisition [Line Items]
Contingent consideration maximum potential pay out		$ 3.7
Settlement of deferred payment obligation	$ 40.9
Acquisition date fair value of contingent consideration liability		$ 0.8
Purchase price, net of cash acquired			258.3
RPM | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
RPM | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
TD Ameritrade
Business Acquisition [Line Items]
Purchase price, net of cash acquired			$ 61.5
TD Ameritrade | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Summit
Business Acquisition [Line Items]
Contingent consideration maximum potential pay out		$ 11.0
Acquisition date fair value of contingent consideration liability		$ 7.3
Purchase price, net of cash acquired				26.4
Summit | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		7 years
Summit | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
ActivePath
Business Acquisition [Line Items]
Purchase price, net of cash acquired				21.8
ActivePath | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		2 years
ActivePath | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years
FundAssist
Business Acquisition [Line Items]
Acquisition date fair value of contingent consideration liability		$ 5.3
Purchase price, net of cash acquired				$ 41.3
FundAssist | Customer Relationships
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		6 years
FundAssist | Software Technology
Business Acquisition [Line Items]
Acquired finite-lived intangible assets, weighted average useful life		5 years