Employee Benefit Plans (Details) - Schedule of net periodic costs - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Feb. 28, 2018	May 31, 2018	May 31, 2017	May 31, 2016
Components of net periodic (benefit) cost:
Service cost			$ 0.1
Other Postretirement Benefits [Member]
Components of net periodic (benefit) cost:
Service cost		$ 0.0	0.0	$ 0.0
Interest cost		0.8	0.9	1.4
Expected return on assets		0.0	0.0	0.0
Net amortization and deferrals		0.0	0.0	(0.1)
Settlement charge		0.0	0.0	0.0
Amortization of net actuarial loss		0.1	0.4	2.8
Net periodic (benefit) cost		0.9	1.3	4.1
U.S. [Member] | Pension Plans [Member]
Components of net periodic (benefit) cost:
Service cost		0.0	0.0	0.0
Interest cost		1.9	3.2	4.6
Expected return on assets		(4.1)	(6.1)	(6.5)
Net amortization and deferrals		0.0	0.0	0.0
Settlement charge	$ 57.3	57.3	0.0	0.0
Amortization of net actuarial loss		0.9	0.9	0.8
Net periodic (benefit) cost		56.0	(2.0)	(1.1)
U.K. [Member] | Pension Plans [Member]
Components of net periodic (benefit) cost:
Service cost		0.0	0.0	0.0
Interest cost		1.1	1.2	1.5
Expected return on assets		(1.0)	(1.0)	(1.3)
Net amortization and deferrals		0.0	0.0	0.0
Settlement charge		0.0	0.0	0.0
Amortization of net actuarial loss		1.2	0.8	0.9
Net periodic (benefit) cost		$ 1.3	$ 1.0	$ 1.1