Acquisitions - Financial Information on Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition [Line Items]
Cash payments, net of cash acquired	$ 339.1	$ 354.7	$ 108.3
Goodwill	1,674.5	1,500.0
Fiscal Year 2020 Acquisitions
Business Acquisition [Line Items]
Cash payments, net of cash acquired	280.3
Deferred payments, net	9.0
Contingent consideration liability	7.0
Aggregate purchase price	296.3
Net tangible assets acquired / (liabilities assumed)	(10.8)
Goodwill	185.3
Intangible assets	121.8
Shadow Financial
Business Acquisition [Line Items]
Cash payments, net of cash acquired	35.6
Deferred payments, net	2.9
Contingent consideration liability	0.0
Aggregate purchase price	38.5
Net tangible assets acquired / (liabilities assumed)	(0.2)
Intangible assets	21.1
Fi360
Business Acquisition [Line Items]
Cash payments, net of cash acquired	116.0
Deferred payments, net	3.5
Contingent consideration liability	0.0
Aggregate purchase price	119.5
Net tangible assets acquired / (liabilities assumed)	(7.9)
Intangible assets	43.1
Clear-Structure
Business Acquisition [Line Items]
Cash payments, net of cash acquired	59.1
Deferred payments, net	2.6
Contingent consideration liability	7.0
Aggregate purchase price	68.7
Net tangible assets acquired / (liabilities assumed)	0.6
Intangible assets	23.9
Funds-Library
Business Acquisition [Line Items]
Cash payments, net of cash acquired	69.6
Deferred payments, net	0.0
Contingent consideration liability	0.0
Aggregate purchase price	69.6
Net tangible assets acquired / (liabilities assumed)	(3.3)
Intangible assets	$ 33.8
Fiscal Year 2019 Acquisitions
Business Acquisition [Line Items]
Cash payments, net of cash acquired		354.7
Deferred payments, net		41.4
Contingent consideration liability		7.9
Aggregate purchase price		404.0
Net tangible assets acquired / (liabilities assumed)		3.9
Goodwill		239.8
Intangible assets		160.3
Rockall
Business Acquisition [Line Items]
Cash payments, net of cash acquired		34.9
Deferred payments, net		0.5
Contingent consideration liability		7.0
Aggregate purchase price		42.4
Net tangible assets acquired / (liabilities assumed)		(2.9)
Intangible assets		14.2
RPM
Business Acquisition [Line Items]
Cash payments, net of cash acquired		258.3
Deferred payments, net		40.9
Contingent consideration liability		0.8
Aggregate purchase price		300.1
Net tangible assets acquired / (liabilities assumed)		6.8
Intangible assets		111.7
TD Ameritrade
Business Acquisition [Line Items]
Cash payments, net of cash acquired		61.5
Deferred payments, net		0.0
Contingent consideration liability		0.0
Aggregate purchase price		61.5
Net tangible assets acquired / (liabilities assumed)		0.0
Intangible assets		$ 34.4
Fiscal Year 2018 Acquisitions
Business Acquisition [Line Items]
Cash payments, net of cash acquired			89.5
Deferred payments, net			3.8
Contingent consideration liability			9.2
Aggregate purchase price			102.5
Net tangible assets acquired / (liabilities assumed)			(11.7)
Goodwill			76.3
Intangible assets			38.0
Summit
Business Acquisition [Line Items]
Cash payments, net of cash acquired			26.4
Deferred payments, net			1.4
Contingent consideration liability			2.7
Aggregate purchase price			30.6
Net tangible assets acquired / (liabilities assumed)			0.2
Goodwill			18.5
Intangible assets			12.0
ActivePath
Business Acquisition [Line Items]
Cash payments, net of cash acquired			21.8
Deferred payments, net			2.4
Contingent consideration liability			0.0
Aggregate purchase price			24.2
Net tangible assets acquired / (liabilities assumed)			(10.0)
Goodwill			28.7
Intangible assets			5.6
FundAssist
Business Acquisition [Line Items]
Cash payments, net of cash acquired			41.3
Deferred payments, net			0.0
Contingent consideration liability			6.4
Aggregate purchase price			47.7
Net tangible assets acquired / (liabilities assumed)			(1.9)
Goodwill			29.2
Intangible assets			$ 20.4