Equity (Tables)

9 Months Ended

Sep. 30, 2011

Stockholders' Equity Note [Abstract]

Comprehensive Income (Loss) Note [Table Text Block]

Comprehensive income attributable to Juniper Networks consists of the following (in millions):

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2011			2010		2011			2010
Consolidated net income	$	83.7		$	134.3	$	328.8		$	429.3
Other comprehensive income (loss), net of tax:
Change in unrealized (loss) gain on investments, net of tax of nil	(8.7		)	8.7		(5.8		)	7.0
Change in foreign currency translation adjustment, net of tax of nil	(7.5		)	6.3		1.7			(1.2		)
Total other comprehensive income (loss), net of tax	(16.2		)	15.0		(4.1		)	5.8
Consolidated comprehensive income	67.5			149.3		324.7			435.1
Adjust for comprehensive loss (income) attributable to noncontrolling interest, net of tax	—			0.2		0.1			(1.1		)
Comprehensive income attributable to Juniper Networks	$	67.5		$	149.5	$	324.8		$	434.0

Summary of stockholders' equity [Table Text Block]

The following table summarizes equity activity for the three and nine months ended September 30, 2011 (in millions):

	Common Stock & Additional Paid-in-Capital			Accumulated Other Comprehensive Income (Loss)			Accumulated Deficit			Non- controlling Interest			Total Equity
Balance at December 31, 2010	$	9,717.8		$	(1.3	)	$	(3,108.3	)	$	0.6		$	6,608.8
Consolidated net income	—			—			129.8			(0.1		)	129.7
Change in unrealized gain on investments, net of tax of nil	—			4.4			—			—			4.4
Change in foreign currency translation adjustment, net of tax of nil	—			6.6			—			—			6.6
Issuance of shares in connection with Employee Stock Purchase Plan	23.7			—			—			—			23.7
Exercise of stock options by employees	241.7			—			—			—			241.7
Repurchase and retirement of common stock	(70.3		)	—			(129.9		)	—			(200.2		)
Repurchases related to net issuances	(1.8		)	—			(3.1		)	—			(4.9		)
Share-based compensation expense	47.6			—			—			—			47.6
Adjustment related to tax benefit from employee stock option plans	39.4			—			—			—			39.4
Balance at March 31, 2011	9,998.1			9.7			(3,111.5		)	0.5			6,896.8
Consolidated net income	—			—			115.6			(0.1		)	115.5
Change in unrealized loss on investments, net of tax of nil	—			(1.5		)	—			—			(1.5		)
Change in foreign currency translation adjustment, net of tax of nil	—			2.6			—			—			2.6
Exercise of stock options by employees	37.9			—			—			—			37.9
Repurchase and retirement of common stock	(55.2		)	—			(94.8		)	—			(150.0		)
Share-based compensation expense	58.6			—			—			—			58.6
Adjustment related to tax benefit from employee stock option plans	2.0			—			—			—			2.0
Balance at June 30, 2011	10,041.4			10.8			(3,090.7		)	0.4			6,961.9
Consolidated net income	—			—			83.7			—			83.7
Change in unrealized loss on investments, net of tax of nil	—			(8.7		)	—			—			(8.7		)
Change in foreign currency translation adjustment, net of tax of nil	—			(7.5		)	—			—			(7.5		)
Issuance of shares in connection with Employee Stock Purchase Plan	28.0			—			—			—			28.0
Exercise of stock options by employees	8.3			—			—			—			8.3
Repurchase and retirement of common stock	(130.7		)	—			(60.3		)	—			(191.0		)
Repurchases related to net issuances	(1.2		)	—			(1.2		)	—			(2.4		)
Share-based compensation expense	59.0			—			—			—			59.0
Adjustment related to tax benefit from employee stock option plans	6.9			—						—			6.9
Balance at September 30, 2011	$	10,011.7		$	(5.4	)	$	(3,068.5	)	$	0.4		$	6,938.2

The following table summarizes equity activity for the three and nine months ended September 30, 2010 (in millions):

	Common Stock & Additional Paid-in-Capital			Accumulated Other Comprehensive Income (Loss)			Accumulated Deficit			Non- controlling Interest			Total Equity
Balance at December 31, 2009	$	9,060.1		$	(1.4	)	$	(3,236.5	)	$	2.6		$	5,824.8
Consolidated net income	—			—			163.1			1.5			164.6
Change in unrealized loss on investments, net of tax of nil	—			(0.4		)	—			—			(0.4		)
Change in foreign currency translation adjustment, net of tax of nil	—			(2.7		)	—			—			(2.7		)
Issuance of shares in connection with Employee Stock Purchase Plan	20.8			—			—			—			20.8
Exercise of stock options by employees	101.2			—			—			—			101.2
Return of capital to noncontrolling interest	—			—			—			(2.0		)	(2.0		)
Repurchase and retirement of common stock	(5.7		)	—			(68.7		)	—			(74.4		)
Repurchases related to net issuances	—			—			(1.8		)	—			(1.8		)
Share-based compensation expense	40.6			—			—			—			40.6
Adjustment related to tax benefit from employee stock option plans	50.6			—			—			—			50.6
Balance at March 31, 2010	9,267.6			(4.5		)	(3,143.9		)	2.1			6,121.3
Consolidated net income	—			—			130.5			(0.2		)	130.3
Change in unrealized loss on investments, net of tax of nil	—			(1.3		)	—			—			(1.3		)
Change in foreign currency translation adjustment, net of tax of nil	—			(4.8		)	—			—			(4.8		)
Exercise of stock options by employees	53.7			—			—			—			53.7
Return of capital to noncontrolling interest	—			—			—			(1.0		)	(1.0		)
Shares assumed in connection with business acquisition	2.3			—			—			—			2.3
Repurchase and retirement of common stock	(9.1		)	—			(168.3		)	—			(177.4		)
Share-based compensation expense	43.3			—			—			—			43.3
Adjustment related to tax benefit from employee stock option plans	5.4			—			—			—			5.4
Balance at June 30, 2010	9,363.2			(10.6		)	(3,181.7		)	0.9			6,171.8
Consolidated net income	—			—			134.5			(0.2		)	134.3
Change in unrealized loss on investments, net of tax of nil	—			8.7			—			—			8.7
Change in foreign currency translation adjustment, net of tax of nil	—			6.3			—			—			6.3
Issuance of shares in connection with Employee Stock Purchase Plan	21.0			—			—			—			21.0
Exercise of stock options by employees	62.4			—			—			—			62.4
Repurchase and retirement of common stock	(44.4		)	—			(90.5		)	—			(134.9		)
Repurchases related to net issuances	—			—			(0.1		)	—			(0.1		)
Share-based compensation expense	43.1			—			—			—			43.1
Adjustment related to tax benefit from employee stock option plans	4.3			—			—			—			4.3
Balance at September 30, 2010	$	9,449.6		$	4.4		$	(3,137.8	)	$	0.7		$	6,316.9