Annual report pursuant to Section 13 and 15(d)

Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details)

v3.10.0.1
Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($)
$ in Millions
May 31, 2018
May 31, 2017
Income Taxes [Abstract]    
Compensation and employee benefit liabilities $ 15.0 $ 23.1
Other current liabilities 6.5 9.1
Tax credit carry forward 0.2 39.3
Depreciation 3.6 7.3
Stock-based compensation 11.6 21.8
Unrealized losses on available-for-sale securities 9.2  
Net operating loss ("NOL") carry forward 5.9 2.9
Tax benefit of uncertain tax positions 3.7 6.4
Other 2.3 4.7
Gross deferred tax assets 58.0 114.6
Capitalized software 39.4 54.8
Depreciation   1.6
Goodwill and Intangible assets 49.0 66.8
Revenue not subject to current taxes 18.4 13.6
Unrealized gains on available-for-sale securities   11.7
Gross deferred tax liabilities 106.8 148.5
Net deferred tax liability $ (48.8) $ (33.9)