Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) € in Millions, $ in Millions	Aug. 31, 2017 USD ($)	May 31, 2017 EUR (€)	May 31, 2017 USD ($)	Nov. 30, 2016 USD ($)	Aug. 31, 2016 USD ($)	May 31, 2016 USD ($)	Nov. 30, 2015 USD ($)	May 31, 2015 EUR (€)	May 31, 2015 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	$ 5,027.8			$ 1,056.9	$ 1,057.3
Long-term debt, fair value	5,154.7			1,118.3	1,155.3
Liabilities [Abstract]
Contingent consideration related to D&A acquisition		€ 26.1	$ 29.3	28.9		$ 30.1	$ 27.1	€ 25.2	$ 27.7
Recurring
Assets [Abstract]
Cash and cash equivalents	166.1			118.4	134.2
Insurance contracts	115.2			106.0	106.6
Bonds and other long-term investments	8.1			10.2	10.0
Interest rate derivatives	0.3				5.5
Foreign currency derivatives	5.5			4.9	3.4
Total assets	295.2			239.5	259.7
Liabilities [Abstract]
Foreign currency derivatives	9.1			5.4	2.3
Interest rate derivatives				1.2
Contingent consideration related to D&A acquisition				28.9	30.1
Total liabilities	9.1			35.5	32.4
Recurring | Level 1
Assets [Abstract]
Cash and cash equivalents	166.1			118.4	134.2
Insurance contracts	0.0			0.0	0.0
Bonds and other long-term investments	8.1			10.2	10.0
Interest rate derivatives	0.0				0.0
Foreign currency derivatives	0.0			0.0	0.0
Total assets	174.2			128.6	144.2
Liabilities [Abstract]
Foreign currency derivatives	0.0			0.0	0.0
Total liabilities	0.0			0.0	0.0
Recurring | Level 2
Assets [Abstract]
Cash and cash equivalents	0.0			0.0	0.0
Insurance contracts	115.2			106.0	106.6
Bonds and other long-term investments	0.0			0.0	0.0
Interest rate derivatives	0.3				5.5
Foreign currency derivatives	5.5			4.9	3.4
Total assets	121.0			110.9	115.5
Liabilities [Abstract]
Foreign currency derivatives	9.1			5.4	2.3
Interest rate derivatives				1.2
Total liabilities	9.1			6.6	2.3
Recurring | Level 3
Assets [Abstract]
Cash and cash equivalents	0.0			0.0	0.0
Insurance contracts	0.0			0.0	0.0
Bonds and other long-term investments	0.0			0.0	0.0
Interest rate derivatives	0.0				0.0
Foreign currency derivatives	0.0			0.0	0.0
Total assets	0.0			0.0	0.0
Liabilities [Abstract]
Foreign currency derivatives	0.0			0.0	0.0
Contingent consideration related to D&A acquisition				28.9	30.1
Total liabilities	$ 0.0			$ 28.9	$ 30.1