Net Income per Share (Tables)

12 Months Ended

Dec. 31, 2011

Earnings Per Share [Abstract]

Schedule of Calculation of Numerator and Denominator in Earnings Per Share [Table Text Block]

The Company computed basic and diluted net income per share attributable to Juniper Networks common stockholders as follows (in millions, except per share amounts):

	Years Ended December 31,
	2011		2010		2009
Numerator:
Net income attributable to Juniper Networks	$	425.1	$	618.4	$	117.0
Denominator:
Weighted-average shares used to compute basic net income per share	529.8		522.4		523.6
Dilutive effect of employee stock awards	11.6		16.4		10.4
Weighted-average shares used to compute diluted net income per share	541.4		538.8		534.0
Net income per share attributable to Juniper Networks common stockholders:
Basic	$	0.80	$	1.18	$	0.22
Diluted	$	0.79	$	1.15	$	0.22