Summary of Significant Accounting Policies (Details) $ / shares in Units, shares in Millions	3 Months Ended															12 Months Ended
	Jun. 30, 2017 USD ($) $ / shares		Mar. 31, 2017 USD ($) $ / shares	[3]	Dec. 31, 2016 USD ($) $ / shares	[4]	Sep. 30, 2016 USD ($) $ / shares	[5]	Jun. 30, 2016 USD ($) $ / shares		Mar. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	[7]	Sep. 30, 2015 USD ($) $ / shares		Jun. 30, 2017 USD ($) business $ / shares shares	Jun. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares shares		Jun. 30, 2014 USD ($)
Summary of Significant Accounting Policies [Line Items]
Income Tax Expense (Benefit)																$ 797,700,000	$ 741,300,000	$ 694,200,000
Operating Leases, Rent Expense																$ 234,500,000	201,700,000	201,800,000
Number of businesses acquired | business																2
Percent of Level Two Investment Pricing Inputs Provided by Independent Pricing Service	99.00%															99.00%
Goodwill	$ 1,741,000,000								$ 1,682,000,000							$ 1,741,000,000	1,682,000,000	1,793,500,000	[1]
Net earnings from continuing operations	$ 265,800,000	[2]	$ 587,700,000		$ 510,900,000		$ 368,700,000		$ 282,000,000	[6]	$ 532,500,000	$ 341,400,000		$ 337,500,000	[8]	$ 1,733,400,000	$ 1,493,400,000	$ 1,376,500,000
Weighted average shares, Basic | shares																447.8	457.0	472.6
Effect of Employee Stock Option Shares | shares																0.9	0.8	1.6
Effect of Employee Restricted Stock Shares | shares																1.6	1.3	1.6
Weighted average shares, Diluted | shares																450.3	459.1	475.8
EPS from continuing operations, Basic (in dollars per share) | $ / shares	$ 0.60	[2]	$ 1.32		$ 1.14		$ 0.82		$ 0.62	[6]	$ 1.17	$ 0.75		$ 0.73	[8]	$ 3.87	$ 3.27	$ 2.91
EPS from continuing operations, Diluted (in dollars per share) | $ / shares	$ 0.59	[2]	$ 1.31		$ 1.13		$ 0.81		$ 0.62	[6]	$ 1.17	$ 0.74		$ 0.72	[8]	$ 3.85	$ 3.25	$ 2.89
Options excluded from the calculation of diluted earnings per share because their exercise prices exceeded the average market price | shares																1.0	1.8	0.4
Unrecognized Tax Benefits	$ 74,600,000								$ 27,400,000							$ 74,600,000	$ 27,400,000	$ 27,100,000		$ 56,500,000
Tax Settlements Future Impact Potential On Earnings Maximum																35,000,000
Debt Instrument, Issuance Date														Sep. 08, 2015
Debt Instrument, Face Amount	$ 2,000,000,000															2,000,000,000
Net Cash Provided by (Used in) Operating Activities																$ 2,125,900,000	1,897,300,000	1,974,000,000
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Internal Use Software Life of Asset																3 years
Minimum [Member] | Data Processing Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																2 years
Minimum [Member] | Building [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																20 years
Minimum [Member] | Furniture and Fixtures [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																4 years
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Internal Use Software Life of Asset																5 years
Maximum [Member] | Data Processing Equipment [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																5 years
Maximum [Member] | Building [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																40 years
Maximum [Member] | Furniture and Fixtures [Member]
Summary of Significant Accounting Policies [Line Items]
Property, Plant, and Equipment Useful Life																7 years
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09 [Member]
Summary of Significant Accounting Policies [Line Items]
Income Tax Expense (Benefit)																$ (32,100,000)
Net Cash Provided by (Used in) Operating Activities																	$ 37,400,000	$ 68,400,000

[1] The goodwill balance at June 30, 2015 is net of accumulated impairment losses of $42.7 million related to the Employer Services segment.

[2] Earnings from continuing operations before income taxes; net earnings from continuing operations; and basic and diluted EPS from continuing operations include charges for the Workforce Optimization Effort and Service Alignment Initiative. The combined impact decreased earnings from continuing operations before income taxes by $43.5 million and, net earnings from continuing operations and net earnings by $27.1 million and basic and diluted earnings per share from continuing operations by $0.06.

[3] Earnings from continuing operations before income taxes; net earnings from continuing operations; and basic and diluted EPS from continuing operations include charges for the Service Alignment Initiative. This decreased earnings from continuing operations before income taxes by $0.6 million, and net earnings from continuing operations and net earnings by $0.4 million, and had no impact on basic and diluted earnings per share from continuing operations.

[4] Earnings from continuing operations before income taxes; net earnings from continuing operations; and basic and diluted EPS from continuing operations include the gain on the sale of the COBRA and CHSA businesses. This increased earnings from continuing operations before income taxes by $205.4 million, net earnings from continuing operations and net earnings by $121.4 million, and basic and diluted earnings per share from continuing operations by $0.27.

[5] Earnings from continuing operations before income taxes; net earnings from continuing operations; and basic and diluted EPS from continuing operations include the charge for the Service Alignment Initiative. This decreased earnings from continuing operations before income taxes by $39.9 million, net earnings from continuing operations by $24.8 million and basic and diluted earnings per share from continuing operations by $0.05.

[6] Earnings from continuing operations before income taxes; net earnings from continuing operations; net earnings; and basic and diluted EPS from continuing operations include the charge for the Workforce Optimization Effort. This decreased earnings from continuing operations before income taxes by $48.2 million net earnings from continuing operations and net earnings by $31.8 million and basic and diluted earnings per share from continuing operations by $0.07.

[7] Earnings from continuing operations before income taxes; net earnings from continuing operations; net earnings; and basic and diluted EPS from continuing operations include the gain on sale of a building. This increased earnings from continuing operations before income taxes by $13.9 million net earnings from continuing operations and net earnings by $8.6 million and basic and diluted earnings per share from continuing operations by $0.02.

[8] Earnings from continuing operations before income taxes; net earnings from continuing operations; net earnings; and basic and diluted EPS from continuing operations include the gain on the sale of AMD. This increased earnings from continuing operations before income taxes by $29.1 million, net earnings from continuing operations and net earnings by $21.8 million, and basic and diluted earnings per share from continuing operations by $0.05