Business Combinations (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		5 Months Ended	9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2016	Oct. 31, 2015	Jan. 31, 2016
Business Combination, Separately Recognized Transactions [Line Items]
Goodwill	$ 993.3		$ 993.3	$ 993.3		$ 954.9
Revenues	389.0	$ 365.0		1,148.6	$ 1,209.2
Net earnings (loss)	$ 19.8	$ (400.8)		$ 35.6	$ (375.5)
Diluted net earnings (loss) per share	$ 0.38	$ (7.68)		$ 0.68	$ (7.19)
Herndon
Business Combination, Separately Recognized Transactions [Line Items]
Accounts receivable-trade	$ 12.3		12.3	$ 12.3
Inventories	103.2		103.2	103.2
Other current and non-current assets	1.1		1.1	1.1
Property and equipment	2.3		2.3	2.3
Goodwill	44.7		44.7	44.7
Identified intangibles	68.9		68.9	68.9
Accounts payable	(9.7)		(9.7)	(9.7)
Other current and non-current liabilities	(2.0)		(2.0)	(2.0)
Total consideration paid	220.8		220.8	220.8
Unaudited pro forma revenues had business acquisitions occurred at the beginning of the period		$ 399.5		1,198.8	$ 1,309.3
Unaudited pro forma net earnings (loss) had business acquisitions occurred at the beginning of the period		$ (398.4)		$ 39.1	$ (368.6)
Unaudited pro forma diluted net earnings (loss) per share had business acquisitions occurred at the beginning of the period		$ (7.63)		$ 0.75	$ (7.06)
Revenues	389.0		$ 56.7
Net earnings (loss)	$ 19.8
Diluted net earnings (loss) per share	$ 0.38