Consolidated and Combined Statements Of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings (Deficit)	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Jan. 31, 2015	$ 0.5	$ 2,644.8		$ 11.3	$ (55.5)	$ 2,601.1
Balance (shares) at Jan. 31, 2015	52.8
Sale of stock under employee stock purchase plan		1.8				1.8
Return to provision true-up related to pre spin-off and other		1.0				1.0
Purchase of treasury stock			$ (12.5)			(12.5)
Restricted stock grants, net of forfeitures and restricted stock unit vesting		14.8		0.8		15.6
Restricted stock grants, net of forfeitures and restricted stock unit vesting (in shares)	0.5
Net earnings (loss)				(385.8)		(385.8)
Net foreign currency translation adjustments					(18.7)	(18.7)
Balance at Jan. 31, 2016	$ 0.5	2,662.4	(12.5)	(373.7)	(74.2)	2,202.5
Balance (shares) at Jan. 31, 2016	53.3
Sale of stock under employee stock purchase plan		2.0				2.0
Purchase of treasury stock			(41.9)			(41.9)
Restricted stock grants, net of forfeitures and restricted stock unit vesting		22.1		(2.5)		19.6
Restricted stock grants, net of forfeitures and restricted stock unit vesting (in shares)	0.2
Net earnings (loss)				48.2		48.2
Net foreign currency translation adjustments					(9.3)	(9.3)
Balance at Jan. 31, 2017	$ 0.5	2,686.5	(54.4)	(328.0)	(83.5)	2,221.1
Balance (shares) at Jan. 31, 2017	53.5
Sale of stock under employee stock purchase plan		2.3				2.3
Purchase of treasury stock			(128.3)			(128.3)
Restricted stock grants, net of forfeitures and restricted stock unit vesting		67.7		(7.0)		60.7
Restricted stock grants, net of forfeitures and restricted stock unit vesting (in shares)	1.1
Net earnings (loss)				53.4		53.4
Net foreign currency translation adjustments					59.1	59.1
Cumulative effect of adoption of new accounting principle (See Note 1)				1.6		1.6
Balance at Jan. 31, 2018	$ 0.5	$ 2,756.5	$ (182.7)	$ (280.0)	$ (24.4)	$ 2,269.9
Balance (shares) at Jan. 31, 2018	54.6