Financing Arrangements (Tables)

3 Months Ended

Aug. 31, 2015

Financing Arrangements

Summary of carrying amount of debt

	August 31,			May 31,
	2015			2015
Revolving Credit Facility expiring March 24, 2020 with interest payable monthly	$	105.0		$	50.0
Industrial revenue bond (secured by property, plant and equipment) due August 1, 2018 with interest payable monthly	25.0			25.0
Note payable due March 9, 2017 with floating interest rate, payable semi-annually on June 1 and December 1	15.0			20.0
Convertible notes payable due March 1, 2016 with interest at 2.25% payable semi-annually on March 1 and September 1	34.5			48.0
Mortgage loan (secured by Wood Dale, Illinois facility) due August 1, 2015	—			11.0
Total debt	179.5			154.0
Current maturities of debt	(44.5		)	(69.0		)
Long-term debt	$	135.0		$	85.0

Schedule of interest expense associated with the convertible notes

	Three Months Ended
	August 31,
	2015		2014
Coupon interest	$	0.3	$	0.5
Amortization of deferred financing fees	—		0.1
Amortization of discount	0.6		0.7
Interest expense related to convertible notes	$	0.9	$	1.3