Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Jan. 31, 2016	Jan. 31, 2015
Deferred tax assets:
Inventory reserves	$ 15.4	$ 12.8
Accrued liabilities	15.7	11.7
Intangible assets	84.2
Net operating loss carryforward	59.5	24.8
Inventory capitalization	10.7	10.5
Other	5.2	10.4
Gross deferred tax assets	190.7	70.2
Deferred tax liabilities:
Intangible assets	(16.1)	(72.9)
Depreciation	(5.5)	(57.2)
Deferred tax liabilities	(21.6)	(130.1)
Net deferred tax asset (liability) before valuation allowance	169.1	(59.9)
Valuation allowance	(21.9)	(24.8)
Net deferred tax asset	$ 147.2
Net deferred tax liability		$ (84.7)