Quarterly report pursuant to Section 13 or 15(d)

Description of Business, Basis of Presentation, and Significant Accounting Policies (Schedule of Recast of Selected Unaudited Consolidated Balance Sheet) (Details)

v3.10.0.1
Description of Business, Basis of Presentation, and Significant Accounting Policies (Schedule of Recast of Selected Unaudited Consolidated Balance Sheet) (Details) - USD ($)
$ in Millions
Nov. 30, 2018
May 31, 2018
Assets    
Accounts receivable, net of allowance for doubtful accounts $ 562.6 $ 492.4 [1]
Prepaid expenses and other current assets 234.2 224.0 [1]
Long-term deferred costs 354.0 361.0 [1],[2]
Liabilities and stockholders' equity    
Accounts payable 70.6 73.7 [1]
Deferred revenue 42.5 34.6 [1]
Deferred income taxes 161.6 154.4 [1]
Other long-term liabilities 89.8 89.1 [1]
Retained earnings $ 1,302.6 1,262.6 [1]
ASU 2014-09 [Member] | As Previously Reported [Member]    
Assets    
Accounts receivable, net of allowance for doubtful accounts   531.4
Prepaid expenses and other current assets   75.8
Long-term deferred costs [2]   18.5
Liabilities and stockholders' equity    
Accounts payable   74.5
Deferred revenue   24.3
Deferred income taxes   48.8
Other long-term liabilities   84.8
Retained earnings   930.3
ASU 2014-09 [Member] | Adjustments [Member]    
Assets    
Accounts receivable, net of allowance for doubtful accounts   (39.0)
Prepaid expenses and other current assets   148.2
Long-term deferred costs [2]   342.5
Liabilities and stockholders' equity    
Accounts payable   (0.8)
Deferred revenue   10.3
Deferred income taxes   105.6
Other long-term liabilities   4.3
Retained earnings   $ 332.3
[1] Amounts have been adjusted to reflect the adoption of ASC Topic 606.
[2] Amounts were previously reported as a component of other long-term assets on the Consolidated Balance Sheets included in the Company's fiscal 2018 Form 10-K. Long-term deferred costs are separately presented on the Consolidated Balance Sheets contained in this Form 10-Q.