Consolidated Balance Sheets - USD ($)	Jun. 30, 2019		Jun. 30, 2018
Statement of Financial Position [Abstract]
Long-term Marketable Securities Under Reverse Repurchase Agreements	$ 261,400,000
Current assets:
Cash and cash equivalents	1,949,200,000		$ 2,170,000,000
Accounts receivable, net of allowance for doubtful accounts of $54.9 and $51.3, respectively	2,439,300,000		1,984,200,000
Other current assets	519,600,000		531,300,000
Total current assets before funds held for clients	4,908,100,000		4,685,500,000
Funds held for clients	29,434,200,000		27,137,800,000
Total current assets	34,342,300,000		31,823,300,000
Long-term receivables, net of allowance for doubtful accounts of $0.4 and $0.5, respectively	23,800,000		25,500,000
Property, plant and equipment, net	764,200,000		793,700,000
Capitalized Contract Cost, Net	2,428,500,000		2,377,400,000
Other assets	934,400,000		699,300,000
Goodwill	2,323,000,000		2,243,500,000
Intangible assets, net	1,071,500,000		886,400,000
Total assets	41,887,700,000		38,849,100,000
Liabilities
Accounts payable	125,500,000		135,400,000
Accrued expenses and other current liabilities	1,759,000,000		1,547,600,000
Accrued payroll and payroll-related expenses	721,100,000		667,700,000
Dividends payable	340,100,000		298,900,000
Short-term deferred revenues	220,700,000		225,700,000
Income taxes payable	54,800,000		43,900,000
Total current liabilities before client funds obligations	3,483,200,000		2,919,200,000
Client funds obligations	29,144,500,000		27,493,500,000
Total current liabilities	32,627,700,000		30,412,700,000
Long-term debt	2,002,200,000		2,002,400,000
Other liabilities	798,700,000		728,000,000
Deferred income taxes	659,900,000		522,000,000
Long-term deferred revenues	399,300,000		448,100,000
Total liabilities	36,487,800,000		34,113,200,000
Stockholders' equity:
Preferred stock, $1.00 par value: Authorized, 0.3 shares; issued, none	0		0
Common stock, $0.10 par value: authorized, 1,000.0 shares; issued, 638.7 shares at June 30, 2019 and June 30, 2018; outstanding, 434.2 and 438.8 shares at June 30, 2019 and June 30, 2018, respectively	63,900,000		63,900,000
Capital in excess of par value	1,183,200,000		1,014,800,000
Retained earnings	17,500,600,000		16,546,600,000
Treasury stock - at cost: 204.5 and 199.9 shares at June 30, 2019 and June 30, 2018, respectively	(13,090,500,000)		(12,209,600,000)
Accumulated other comprehensive loss	(257,300,000)		(679,800,000)
Total stockholders’ equity	5,399,900,000		4,735,900,000
Total liabilities and stockholders’ equity	41,887,700,000		38,849,100,000
Cash And Cash Equivalents Under Reverse Repurchase Agreements	600,000
Obligations under reverse repurchase agreements (A)	$ 262,000,000	[1]	$ 0

[1] (A) As of June 30, 2019, $261.4 million of long-term marketable securities and $0.6 million of cash and cash equivalents have been pledged as collateral under the Company's reverse repurchase agreements (see Note 10).