Net Income Per Share (Tables)

12 Months Ended

Jan. 31, 2015

Earnings Per Share [Abstract]

Schedule of Calculation of Numerator and Denominator in Earnings Per Share

The following table sets forth the computation of the numerators and denominators used in the basic and diluted net income per share amounts:

	Fiscal Year Ended January 31,
	2015		2014		2013
Numerator:
Net income	$	81.8	$	228.8	$	247.4
Denominator:
Denominator for basic net income per share—weighted average shares	227.1		224.0		226.4
Effect of dilutive securities	5.3		5.6		5.3
Denominator for dilutive net income per share	232.4		229.6		231.7
Basic net income per share	$	0.36	$	1.02	$	1.09
Diluted net income per share	$	0.35	$	1.00	$	1.07