Financial Data By Segment (Tables)

12 Months Ended

Jun. 30, 2020

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Employer Services		PEO Services		Other		Total
Year ended June 30, 2020
Revenues	$	10,086.6	$	4,511.5	$	(8.3)	$	14,589.8
Earnings before income taxes	3,063.0		605.5		(485.9)		3,182.6
Assets	37,071.7		1,443.2		650.6		39,165.5
Capital expenditures	115.7		—		52.6		168.3
Depreciation and amortization	388.0		3.4		88.6		480.0
Year ended June 30, 2019
Revenues	$	9,942.8	$	4,177.7	$	(10.3)	$	14,110.2
Earnings before income taxes	2,960.9		616.2		(571.5)		3,005.6
Assets	34,606.3		1,584.1		5,697.3		41,887.7
Capital expenditures	98.2		—		64.5		162.7
Depreciation and amortization	321.0		3.5		84.5		409.0
Year ended June 30, 2018
Revenues	$	9,454.8	$	3,828.8	$	(9.4)	$	13,274.2
Earnings before income taxes	2,601.1		541.6		(860.1)		2,282.6
Assets	31,984.2		1,329.8		5,535.1		38,849.1
Capital expenditures	113.9		—		78.0		191.9
Depreciation and amortization	291.9		3.0		82.7		377.6

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	United States		Europe		Canada		Other		Total
Year ended June 30, 2020
Revenues	$	12,740.1	$	1,236.3	$	329.8	$	283.6	$	14,589.8
Assets	$	33,891.0	$	2,162.7	$	2,435.3	$	676.5	$	39,165.5
Year ended June 30, 2019
Revenues	$	12,262.6	$	1,236.8	$	326.6	$	284.2	$	14,110.2
Assets	$	36,508.3	$	2,807.9	$	1,950.5	$	621.0	$	41,887.7
Year ended June 30, 2018
Revenues	$	11,439.8	$	1,242.2	$	321.6	$	270.6	$	13,274.2
Assets	$	33,586.6	$	2,608.6	$	2,073.1	$	580.8	$	38,849.1