Net Income Per Share (Tables)

3 Months Ended

Mar. 31, 2015

Earnings Per Share [Abstract]

Computation of Basic and Diluted Net Income Per Share

The following table sets forth the computation of basic and diluted net income per share: 

	Three Months Ended March 31,
(In millions, except per share data)	2014		2015
Basic net income per share:
Net income	$	25.4	$	28.4
Weighted average shares outstanding:
Common stock	141.0		141.4
Number of shares used in per share computations	141.0		141.4
Net income per share	$	0.18	$	0.20
Diluted net income per share:
Net income	$	25.4	$	28.4
Weighted average shares outstanding:
Common stock	141.0		141.4
Stock options, awards and employee share purchase plans	2.8		2.8
Number of shares used in per share computations	143.8		144.2
Net income per share	$	0.18	$	0.20