Employee Benefit Plans (Details) $ in Millions	3 Months Ended
	Aug. 31, 2015 USD ($)
Employee Benefit Plans (Details) [Line Items]
Minimum threshold to trigger settlement charge	$ 4.6
United States Pension Plan
Employee Benefit Plans (Details) [Line Items]
Pension contributions	0.0
United Kingdom Pension Plan
Employee Benefit Plans (Details) [Line Items]
Pension contributions	0.3
Pension Plans
Employee Benefit Plans (Details) [Line Items]
Contributions expected in current fiscal year	$ 1.3