Employee Benefit Plans (Tables)

6 Months Ended

Nov. 30, 2011

Schedule of Net Benefit Costs [Table Text Block]

	Pension Plans						Post-Retirement Benefits
	Three months ended November 30,						Three months ended November 30,
	2011			2010			2011			2010
Components of net periodic benefit costs:
Service cost	$	0.0		$	0.1		$	0.0		$	0.0
Interest cost		2.1			2.2			0.5			0.4
Expected return on assets		(2.7	)		(2.3	)		—			—
Net amortization of prior service credit		—			—			(0.2	)		(0.2	)
Amortization of loss		0.3			0.4			1.0			0.6
Settlement of Canadian plan		—			3.4			—			—
Net periodic benefit (credit) costs	$	(0.3	)	$	3.8		$	1.3		$	0.8

	Pension Plans						Post-Retirement Benefits
	Six months ended November 30,						Six months ended November 30,
	2011			2010			2011			2010
Components of net periodic benefit costs:
Service cost	$	0.0		$	0.2		$	0.0		$	0.0
Interest cost		4.2			4.4			0.9			0.9
Expected return on assets		(5.4	)		(4.7	)		—			—
Net amortization of prior service credit		—			—			(0.3	)		(0.3	)
Amortization of loss		0.7			0.9			2.1			1.1
Settlement of Canadian plan		—			3.4			—			—
Net periodic benefit (credit) costs	$	(0.5	)	$	4.2		$	2.7		$	1.7