Statements of Consolidated Earnings - USD ($) shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
REVENUES:
TOTAL REVENUES		$ 4,927.8	$ 4,513.0	$ 13,534.4	$ 12,370.6
Costs of revenues:
Operating expenses		2,299.8	2,212.5	6,508.7	6,184.0
Systems development and programming costs		208.6	197.3	622.6	585.8
Depreciation and amortization		115.4	102.4	336.8	306.2
TOTAL COSTS OF REVENUES		2,623.8	2,512.2	7,468.1	7,076.0
Selling, general, and administrative expenses		938.0	817.5	2,594.2	2,319.0
Interest expense		38.3	18.4	146.4	55.3
TOTAL EXPENSES		3,600.1	3,348.1	10,208.7	9,450.3
Other (income)/expense, net		(36.3)	(25.0)	(106.3)	(80.4)
EARNINGS BEFORE INCOME TAXES		1,364.0	1,189.9	3,432.0	3,000.7
Provision for income taxes		320.9	261.4	796.7	677.3
NET EARNINGS		$ 1,043.1	$ 928.5	$ 2,635.3	$ 2,323.4
Earnings Per Share [Abstract]
BASIC EARNINGS PER SHARE (in US$ per share)		$ 2.52	$ 2.22	$ 6.36	$ 5.53
DILUTED EARNINGS PER SHARE (in US$ per share)		$ 2.51	$ 2.21	$ 6.33	$ 5.51
Basic weighted average shares outstanding (shares)		413.7	418.1	414.2	419.8
Diluted weighted average shares outstanding (shares)		415.5	420.2	416.2	422.0
Revenues, other than interest on funds held for clients and PEO revenues
REVENUES:
TOTAL REVENUES		$ 3,088.7	$ 2,882.3	$ 8,437.3	$ 7,911.9
Interest on funds held for clients
REVENUES:
TOTAL REVENUES		249.4	118.0	577.7	325.0
PEO Revenues
REVENUES:
TOTAL REVENUES	[1]	$ 1,589.7	$ 1,512.7	$ 4,519.4	$ 4,133.7

[1] Professional Employer Organization (“PEO”) revenues are net of direct pass-through costs, primarily consisting of payroll wages and payroll taxes of $17,301.8 million and $16,826.6 million for the three months ended March 31, 2023 and 2022, respectively, and $50,688.4 million and $46,863.8 million for the nine months ended March 31, 2023 and 2022, respectively.