Divestitures (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended						12 Months Ended
	Nov. 28, 2016	Sep. 01, 2015	Jun. 26, 2015	Dec. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 205.4	$ 29.1		$ 205.4				$ 29.1
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax [Abstract]
Revenues											$ 0.0	$ 538.8
Earnings from discontinued operations before income taxes											0.0	69.2
Provision for income taxes											0.0	71.6
Net earnings from discontinued operations before gain on disposal of discontinued operations											0.0	(2.4)
Gain on disposal of discontinued operations, less costs to sell			$ 100.9								(1.4)	102.3
Provision for income taxes											(0.5)	23.9
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax											(0.9)	78.4
Net earnings from discontinued operations					$ 0.0	$ 0.0	$ 0.0	$ (0.9)		$ 0.0	$ (0.9)	76.0
Common stock, par value					$ 0.10					$ 0.1	$ 0.10
Separation costs												$ 50.1
CHSA and COBRA [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date	Nov. 28, 2016
AdvancedMD [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date		Sep. 01, 2015
Procure-to-Pay Solutions [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date			Jun. 26, 2015
Dealer [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date									Sep. 30, 2014
CDK Global Inc [Member]
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax [Abstract]
Date of record for ADP stockholders to receive CDK shares									Sep. 24, 2014
Number of CDK shares for three ADP Shares									1.0
Common stock, par value									$ 0.01
ADP shares converted to CDK									3.0
Shares Distributed of CDK common stock									160,600,000
Unvested Shares Distributed								1,000,000