Juniper Networks (JNPR) 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 01, 2013
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'JUNIPER NETWORKS INC	'
Entity Central Index Key	'0001043604	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Current Fiscal Year End Date	'--12-31	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	505,004,236

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net revenues:	'	'	'	'
Product	$900.80	$838.20	$2,546.40	$2,414.80
Service	284.8	280.1	849.1	809.8
Total net revenues	1,185.60	1,118.30	3,395.50	3,224.60
Cost of revenues:	'	'	'	'
Product	325.5	334.7	925	907.9
Service	113.6	109.8	332.7	340.9
Total cost of revenues	439.1	444.5	1,257.70	1,248.80
Gross margin	746.5	673.8	2,137.80	1,975.80
Operating expenses:	'	'	'	'
Research and development	264.6	288.2	784.5	826.5
Sales and marketing	268.7	261	790.1	778.2
General and administrative	61.1	49.4	157.7	152.9
Amortization of purchased intangible assets	1.1	1.1	3.5	3.5
Restructuring and other charges	6	31	21	36.2
Acquisition and litigation charges	0	0.3	10.5	1.3
Total operating expenses	601.5	631	1,767.30	1,798.60
Operating income	145	42.8	370.5	177.2
Other expense, net	-7.5	-4	-30.2	-25.6
Income before income taxes	137.5	38.8	340.3	151.6
Income tax provision	38.4	22	52.3	60.8
Net income	$99.10	$16.80	$288	$90.80
Net income per share:	'	'	'	'
Basic (in dollars per share)	$0.20	$0.03	$0.57	$0.17
Diluted (in dollars per share)	$0.19	$0.03	$0.56	$0.17
Shares used in computing net income per share:	'	'	'	'
Basic (in shares)	501.5	521.2	503	525.4
Diluted (in shares)	508.6	524.5	510.7	530.3

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement of Comprehensive Income [Abstract]	'	'	'	'
Net income	$99.10	$16.80	$288	$90.80
Available-for-sale securities:	'	'	'	'
Change in unrealized gains on available- for-sale securities	65.2	2	70.8	4.1
Reclassification adjustment for realized net gains on available-for-sale securities included in net income	-0.3	-0.3	-0.8	-0.8
Net change in unrealized gains on available-for-sale securities	64.9	1.7	70	3.3
Cash flow hedges:	'	'	'	'
Change in unrealized gains (losses) on cash flow hedges	0.7	4.3	-1.8	6.9
Reclassification adjustment for realized net losses (gains) on cash flow hedges included in net income	0.6	2.4	-0.9	7.4
Net change in unrealized gains (losses) on cash flow hedges	1.3	6.7	-2.7	14.3
Change in foreign currency translation adjustments	4.1	5.2	-5.4	5.3
Other comprehensive income, net of tax	70.3	13.6	61.9	22.9
Comprehensive income	$169.40	$30.40	$349.90	$113.70

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$2,271.50	$2,407.80
Short-term investments	573.7	441.5
Accounts receivable, net of allowances	549.3	438.4
Deferred tax assets, net	129.4	172.6
Prepaid expenses and other current assets	156.5	140.4
Total current assets	3,680.40	3,600.70
Property and equipment, net	868.2	811.9
Long-term investments	1,188.60	988.1
Restricted cash and investments	92.5	106.4
Purchased intangible assets, net	115.9	128.9
Goodwill	4,057.70	4,057.80
Other long-term assets	194.4	138.3
Total assets	10,197.70	9,832.10
Current liabilities:	'	'
Accounts payable	205.6	209.3
Accrued compensation	191.6	279.3
Accrued warranty	28.6	29.7
Deferred revenue	731.9	693.5
Other accrued liabilities	242.9	210.2
Total current liabilities	1,400.60	1,422
Long-term debt	999.3	999.2
Long-term deferred revenue	289.3	229.9
Long-term income taxes payable	117.5	112.4
Other long-term liabilities	79.3	69.1
Total liabilities	2,886	2,832.60
Commitments and contingencies	'	'
Juniper Networks stockholders' equity:	'	'
Convertible preferred stock, $0.00001 par value; 10.0 shares authorized; none issued and outstanding	0	0
Common stock, $0.00001 par value; 1,000.0 shares authorized; 504.6 shares and 508.4 shares issued and outstanding as of September 30, 2013 and December 31, 2012, respectively	0	0
Additional paid-in capital	9,953.90	9,905.70
Accumulated other comprehensive income	66.6	4.7
Accumulated deficit	-2,708.80	-2,911.40
Total Juniper Networks stockholders' equity	7,311.70	6,999
Noncontrolling interest	0	0.5
Total stockholders' equity	7,311.70	6,999.50
Total liabilities and stockholders' equity	$10,197.70	$9,832.10

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets Parentheticals (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]	'	'
Convertible preferred stock - par value	$0.00	$0.00
Convertible preferred stock - shares authorized	10,000,000	10,000,000
Convertible preferred stock - issued	0	0
Convertible preferred stock - outstanding	0	0
Common stock - par value	$0.00	$0.00
Common stock - shares authorized	1,000,000,000	1,000,000,000
Common stock - issued	504,600,000	508,400,000
Common stock - outstanding	504,600,000	508,400,000

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
Cash flows from operating activities:	'		'
Net income	$288		$90.80
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Share-based compensation	180.7		186
Depreciation and amortization	135.1		137.9
Restructuring and other charges	28.6	[1]	88.6	[1]
Deferred income taxes	40.4		-75.1
Gain on investments, net	-7.8		-7.8
Excess tax benefits from share-based compensation	-1.5		-7.2
Other non-cash charges	1.3		0.6
Changes in operating assets and liabilities, net of effects from acquisitions:	'		'
Accounts receivable, net	-111		180.4
Prepaid expenses and other assets	-67		-54
Accounts payable	-1.1		-114
Accrued compensation	-88.6		5.6
Income taxes payable	-26.1		64.7
Other accrued liabilities	-16.8		-24.8
Deferred revenue	97.7		15.9
Net cash provided by operating activities	451.9		487.6
Cash flows from investing activities:	'		'
Purchases of property and equipment	-183		-256.8
Purchases of trading investments	-3.1		-3.8
Purchases of available-for-sale investments	-1,351.60		-1,009.10
Proceeds from sales of available-for-sale investments	860.4		625.2
Proceeds from maturities of available-for-sale investments	287.6		431.7
Payments for business acquisitions, net of cash and cash equivalents acquired	-10		-90.5
Proceeds from sales of privately-held investments	8.4		32.7
Purchases of privately-held investments	-20.4		-11.1
Purchase of licensed software	-10		-65.3
Changes in restricted cash	0		-20.8
Net cash used in investing activities	-421.7		-367.8
Cash flows from financing activities:	'		'
Proceeds from issuance of common stock	123.7		88.2
Purchases and retirement of common stock	-332.1		-400.1
Payment for capital lease obligation	-1.4		-1.4
Customer financing arrangements	41.8		-16.2
Excess tax benefits from share-based compensation	1.5		7.2
Net cash used in financing activities	-166.5		-322.3
Net decrease in cash and cash equivalents	-136.3		-202.5
Cash and cash equivalents at beginning of period	2,407.80		2,910.40
Cash and cash equivalents at end of period	$2,271.50		$2,707.90
[1]	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.

Basis_of_Presentation_Notes

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of presentation	'
	Basis of Presentation
	The unaudited Condensed Consolidated Financial Statements of Juniper Networks, Inc. (the "Company" or "Juniper") have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The Condensed Consolidated Balance Sheet as of December 31, 2012, is derived from the audited Consolidated Financial Statements for the year ended December 31, 2012. In the opinion of management, all adjustments, including normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the three and nine months ended September 30, 2013, are not necessarily indicative of the results that may be expected for the year ending December 31, 2013, or any future period. The information included in this Quarterly Report on Form 10-Q ("Report") should be read in conjunction with “Management's Discussion and Analysis of Financial Condition and Results of Operations,” “Risk Factors,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and footnotes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2012. Certain amounts in the prior year Condensed Consolidated Financial Statements contained in this Quarterly Report on Form 10-Q have been reclassified to conform to the current year presentation.
	The preparation of the financial statements and related disclosures in accordance with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the Condensed Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates under different assumptions or conditions.
	In the third quarter of 2013, the Company realigned certain products from its Platform Systems Division ("PSD") segment to its Software Solutions Division ("SSD") segment related to its acquisition of Contrail Systems Inc. ("Contrail"). In addition, in the first quarter of 2013, the Company consolidated operational oversight and management of all security products within the SSD segment. As a result of this product realignment, security products previously reported in the PSD segment (including the Branch SRX, Branch Firewall, and J Series product families) are now reported in the SSD segment. The Company reclassified the segment data for the prior periods to conform to the current period's presentation. These changes did not impact previously reported consolidated net revenues, operating income, net income, and net income per share. See Note 13, Segments, for further discussion of the Company's product realignment.
	The Company previously owned a 60 percent interest in a joint venture with Nokia Siemens Networks B.V. (“NSN”). Given the Company's majority ownership interest in the joint venture, the accounts of the joint venture were consolidated with the accounts of the Company, and a noncontrolling interest was recorded for the noncontrolling investor's interests in the net assets and operations of the joint venture. In July 2011, NSN and the Company entered into an agreement to cease operation of and dissolve the joint venture and NSN subsequently assumed the activities of the joint venture. The Company terminated the joint venture in 2013 and the termination did not have a material effect on the Company's financial position or results of operations.

Summary_of_Significant_Account

Summary of Significant Accounting Policies (Notes)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Summary of significant accounting policies	'
	Summary of Significant Accounting Policies
	Effective April 1, 2013, the Company extended the useful lives of certain computers and equipment resulting from its actual historical usage, which demonstrated longer useful lives, as well as the planned use of these assets. The change was accounted for as a change in estimate and applied prospectively. For the three and nine months ended September 30, 2013, this change in accounting estimate decreased depreciation expense by approximately $9.4 million and $20.4 million or $0.01 and $0.03 per diluted share, respectively.
	With the exception of the above change in estimate, there have been no material changes to the Company's significant accounting policies as compared to the accounting policies described in Note 2, Significant Accounting Policies, in Notes to Consolidated Financial Statements in Item 8 of Part II of the Annual Report on Form 10-K for the year ended December 31, 2012.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2013-11, Income Taxes (Topic 740)—Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) ("ASU 2013-11") to provide explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. ASU 2013-11 is effective for fiscal years, and interim periods within those years, beginning after December 31, 2013. The Company intends to adopt this standard prospectively in the first quarter of 2014 and the adoption will not result in a change to the tax provision. The Company does not expect a significant impact to its presentation of long-term taxes payable or its deferred tax assets.
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220)—Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02"), which amends FASB Accounting Standards Codification ("ASC") 220, Comprehensive Income to include the reporting of reclassifications from accumulated other comprehensive income to the respective line items in net income. The Company adopted ASU 2013-02 during the first quarter of 2013 and presented the effects within the Condensed Consolidated Statements of Comprehensive Income and the accompanying notes.
	In December 2011, the FASB issued ASU No. 2011-11, Balance Sheet (Topic 210)—Disclosures About Offsetting Assets and Liabilities ("ASU 2011-11"), and in January 2013 issued ASU No. 2013-01, Balance Sheet (Topic 210)—Clarifying the Scope of Disclosures About Offsetting Assets and Liabilities ("ASU 2013-01"). These standards create new disclosure requirements regarding the nature of an entity's rights of setoff and related arrangements associated with its derivative instruments, repurchase agreements, and securities lending transactions. Disclosures of certain instruments subject to enforceable master netting arrangements would be required, irrespective of whether the entity has elected to offset those instruments in the statement of financial position. The Company adopted these standards in the first quarter of 2013 and presented the effects in the accompanying notes.

Business_Combinations_Notes

Business Combinations (Notes)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Business combinations	'
	Business Combinations
	During the nine months ended September 30, 2013, the Company completed a business combination for approximately $10.0 million in cash consideration, of which $0.1 million was allocated to net tangible assets acquired and $9.9 million to intangible assets. The Company's consolidated financial statements include the operating results of this business combination from the date of acquisition, and the inclusion of those results were not material to the Company's consolidated balance sheets and results of operations.
	There were no acquisition-related costs recognized during the three months ended September 30, 2013 and $0.3 million recognized during the three months ended September 30, 2012. The Company recognized $0.2 million and $1.3 million of acquisition-related costs during the nine months ended September 30, 2013 and September 30, 2012, respectively. These acquisition-related costs were expensed in the period incurred and reported as a component of acquisition and litigation charges in the Company's Condensed Consolidated Statements of Operations.

Cash_Equivalents_and_Investmen

Cash Equivalents and Investments (Notes)	9 Months Ended
	Sep. 30, 2013
Cash Equivalents and Investments [Abstract]	'
Cash equivalents and investments	'
	Cash Equivalents and Investments
	Investments in Available-for-Sale and Trading Securities
	The following tables summarize the Company's unrealized gains and losses and fair value of investments designated as available-for-sale and trading securities as of September 30, 2013 and December 31, 2012 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of September 30, 2013
	Cash equivalents:
	Certificates of deposit	$	0.1	$	—		$	—		$	0.1
	Government-sponsored enterprise obligations	8.6		—			—			8.6
	Money market funds	956		—			—			956
	U.S. government securities	85		—			—			85
	Total cash equivalents	1,049.70		—			—			1,049.70
	Restricted investments:
	Money market funds	88.1		—			—			88.1
	Mutual funds	2.4		0.1			—			2.5
	Total restricted investments	90.5		0.1			—			90.6
	Fixed income securities:
	Asset-backed securities	253.8		0.1			(0.2		)	253.7
	Certificates of deposit	24.8		—			—			24.8
	Commercial paper	11.5		—			—			11.5
	Corporate debt securities	768.2		1.5			(0.6		)	769.1
	Foreign government debt securities	15.8		—			—			15.8
	Government-sponsored enterprise obligations	315.1		0.2			(0.2		)	315.1
	U.S. government securities	230.4		0.1			—			230.5
	Total fixed income securities	1,619.60		1.9			(1.0		)	1,620.50
	Publicly-traded equity securities	15.2		111.5			—			126.7
	Total available-for-sale securities	2,775.00		113.5			(1.0		)	2,887.50
	Trading securities in mutual funds(*)	15.1		—			—			15.1
	Total	$	2,790.10	$	113.5		$	(1.0	)	$	2,902.60
	Reported as:
	Cash equivalents	$	1,049.70	$	—		$	—		$	1,049.70
	Restricted investments	90.5		0.1			—			90.6
	Short-term investments	461.7		112			—			573.7
	Long-term investments	1,188.20		1.4			(1.0		)	1,188.60
	Total	$	2,790.10	$	113.5		$	(1.0	)	$	2,902.60
	________________________________
	(*)	Balance includes the Company's non-qualified deferred compensation plan assets.
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of December 31, 2012
	Cash equivalents:
	Certificates of deposit	$	0.6	$	—		$	—		$	0.6
	Commercial paper	10.8		—			—			10.8
	Government-sponsored enterprise obligations	6.1		—			—			6.1
	Money market funds	1,042.60		—			—			1,042.60
	U.S. government securities	165.8		—			—			165.8
	Total cash equivalents	1,225.90		—			—			1,225.90
	Restricted investments:
	Money market funds	102.6		—			—			102.6
	Mutual funds	2.9		0.1			—			3
	Total restricted investments	105.5		0.1			—			105.6
	Fixed income securities:
	Asset-backed securities	226.2		0.3			(0.1		)	226.4
	Certificates of deposit	41.9		—			—			41.9
	Commercial paper	11.6		—			—			11.6
	Corporate debt securities	533.4		2.3			(0.1		)	535.6
	Foreign government debt securities	5		—			—			5
	Government-sponsored enterprise obligations	264.6		0.3			—			264.9
	U.S. government securities	328.6		0.1			—			328.7
	Total fixed income securities	1,411.30		3			(0.2		)	1,414.10
	Publicly-traded equity securities	3		—			(0.1		)	2.9
	Total available-for-sale securities	2,745.70		3.1			(0.3		)	2,748.50
	Trading securities in mutual funds(*)	12.6		—			—			12.6
Total	$	2,758.30	$	3.1		$	(0.3	)	$	2,761.10
Reported as:
Cash equivalents	$	1,225.90	$	—		$	—		$	1,225.90
Restricted investments	105.5		0.1			—			105.6
Short-term investments	441.3		0.3			(0.1		)	441.5
Long-term investments	985.6		2.7			(0.2		)	988.1
Total	$	2,758.30	$	3.1		$	(0.3	)	$	2,761.10
________________________________
(*)	Balance includes the Company's non-qualified deferred compensation plan assets.
The following table presents the maturities of the Company's total fixed income securities as of September 30, 2013 (in millions):
	Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
	Cost		Gains			Losses			Value
Due within one year	$	431.4	$	0.5		$	—		$	431.9
Due between one and five years	1,188.20		1.4			(1.0		)	1,188.60
Total	$	1,619.60	$	1.9		$	(1.0	)	$	1,620.50
The Company had 230 and 98 investments in an unrealized loss position as of September 30, 2013 and December 31, 2012, respectively. The gross unrealized losses related to these investments were primarily due to changes in market interest rates and stock prices. The Company reviews its investments to identify and evaluate investments that have an indication of possible impairment. The Company aggregates its investments by category and length of time the securities have been in a continuous unrealized loss position to facilitate its evaluation.
For the available-for-sale debt securities that have unrealized losses, the Company evaluates whether (i) it has the intention to sell any of these investments and (ii) whether it is more likely than not that it will be required to sell any of these investments before recovery of the entire amortized cost basis. As of September 30, 2013 the Company anticipates that it will recover the entire amortized cost basis of such available-for-sale debt securities and has determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the three and nine months ended September 30, 2013 and September 30, 2012.
For available-for-sale equity securities that have unrealized losses, the Company evaluates whether there is an indication of other-than-temporary impairments. This determination is based on several factors, including the financial condition and near-term prospects of the issuer and the Company's intent and ability to hold the publicly-traded equity securities for a period of time sufficient to allow for any anticipated recovery in market value. During the three and nine months ended September 30, 2013 and September 30, 2012, the Company did not recognize other-than-temporary impairments associated with these investments.
There were no material gross realized gains or losses from available-for-sale and trading securities during the three and nine months ended September 30, 2013 and September 30, 2012. Realized gains and losses are determined based on the specific identification method.
The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of September 30, 2013 and December 31, 2012 (in millions):
	Less than 12 Months					12 Months or Greater					Total
	Fair		Unrealized			Fair			Unrealized		Fair		Unrealized
	Value		Loss			Value			Loss		Value		Loss
As of September 30, 2013
Fixed income securities:
Asset-backed securities	$	172.6	$	(0.2	)	$	—		$	—	$	172.6	$	(0.2	)
Corporate debt securities	286.6		(0.6		)	—			—		286.6		(0.6		)
Foreign government debt securities (*)	15		—			—			—		15		—
Government-sponsored enterprise obligations	158.3		(0.2		)	—			—		158.3		(0.2		)
U.S. government securities (*)	46		—			—			—		46		—
Total fixed income securities	$	678.5	$	(1.0	)	$	—		$	—	$	678.5	$	(1.0	)
________________________________
(*)	Balances for less than twelve months include investments that were in an immaterial loss position as of September 30, 2013.
	Less than 12 Months					12 Months or Greater					Total
	Fair		Unrealized			Fair			Unrealized		Fair		Unrealized
	Value		Loss			Value			Loss		Value		Loss
As of December 31, 2012
Fixed income securities:
Asset-backed securities(*)	$	55.1	$	(0.1	)	$	0.1		$	—	$	55.2	$	(0.1	)
Certificates of deposit	0.3		—			—			—		0.3		—
Commercial paper	10		—			—			—		10		—
Corporate debt securities	116		(0.1		)	—			—		116		(0.1		)
Government-sponsored enterprise obligations	30		—			—			—		30		—
U.S. government securities	68.2		—			—			—		68.2		—
Total fixed income securities	279.6		(0.2		)	0.1			—		279.7		(0.2		)
Publicly-traded equity securities	2.9		(0.1		)	—			—		2.9		(0.1		)
Total available-for sale securities	$	282.5	$	(0.3	)	$	0.1		$	—	$	282.6	$	(0.3	)
________________________________
(*) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2012.
Restricted Cash and Investments
The Company classifies cash and investments designated as available-for-sale securities as restricted cash and investments on its Condensed Consolidated Balance Sheets for: (i) amounts held in escrow accounts, as required in connection with certain acquisitions completed between 2005 and 2013; (ii) the India Gratuity Trust and Israel Retirement Trust, which cover statutory severance obligations in the event of termination of any of the Company's India and Israel employees, respectively; and (iii) the Directors and Officers ("D&O") indemnification trust.
The following table summarizes the Company's cash and investments that are classified as restricted cash and investments in the Condensed Consolidated Balance Sheets (in millions):
	As of
	September 30,		December 31,
	2013		2012
Restricted cash	$	1.9	$	0.8
Restricted investments	90.6		105.6
Total restricted cash and investments	$	92.5	$	106.4
Privately-Held Investments
As of September 30, 2013 and December 31, 2012, the carrying values of the Company’s privately-held investments of $36.5 million and $32.0 million, respectively, were included in other long-term assets in the Condensed Consolidated Balance Sheets. During the third quarter of 2013, certain privately-held investments with carrying values of $7.6 million became public and were reclassified to short-term investments with restrictions of less than one year and resulted in unrealized gains of $100.0 million and recorded as a component of accumulated comprehensive income in the Condensed Consolidated Balance Sheets.
The Company reviews its investments to identify and evaluate investments that have an indication of possible impairment. The Company adjusts the carrying value for its privately-held investments for any impairment if the fair value is less than the carrying value of the respective assets on an other-than-temporary basis.
The Company determined that certain privately-held investments were other-than-temporarily impaired, resulting in impairment charges of $2.1 million and $2.5 million for the three and nine months ended September 30, 2013, respectively, and $6.0 million and $20.0 million for the three and nine months ended September 30, 2012, respectively, that were recorded within other expense, net, in the Condensed Consolidated Statements of Operations.

Fair_Value_Measurements_Notes

Fair Value Measurements (Notes)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair value measurements	'
	Fair Value Measurements
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	The following tables provide a summary of assets and liabilities measured at fair value on a recurring basis and as reported in the Condensed Consolidated Balance Sheets (in millions):
		Fair Value Measurements at September 30, 2013 Using:
		Quoted Prices in		Significant Other			Significant Other
		Active Markets For		Observable			Unobservable
		Identical Assets		Remaining Inputs			Remaining Inputs
		(Level 1)		(Level 2)			(Level 3)		Total
	Assets measured at fair value:
	Available-for-sale securities:
	Asset-backed securities	$	—	$	253.7		$	—	$	253.7
	Certificates of deposit	—		24.9			—		24.9
	Commercial paper	—		11.5			—		11.5
	Corporate debt securities	—		769.1			—		769.1
	Foreign government debt securities	—		15.8			—		15.8
	Government-sponsored enterprise obligations	—		323.7			—		323.7
	Money market funds (1)	1,044.10		—			—		1,044.10
	Mutual funds (2)	2.5		—			—		2.5
	Publicly-traded equity securities	126.7		—			—		126.7
	U.S. government securities	182.2		133.3			—		315.5
	Total available-for-sale securities	1,355.50		1,532.00			—		2,887.50
	Trading securities in mutual funds (3)	15.1		—			—		15.1
	Derivative assets:
	Foreign exchange contracts	—		2.8			—		2.8
	Total assets measured at fair value	$	1,370.60	$	1,534.80		$	—	$	2,905.40
	Liabilities measured at fair value:
	Derivative liabilities:
	Foreign exchange contracts	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total liabilities measured at fair value	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total assets measured at fair value, reported as:
	Cash equivalents	$	961	$	88.7		$	—	$	1,049.70
	Restricted investments	90.6		—			—		90.6
	Short-term investments	259.1		314.6			—		573.7
	Long-term investments	59.9		1,128.70			—		1,188.60
	Prepaid expenses and other current assets	—		2.8			—		2.8
	Total assets measured at fair value	$	1,370.60	$	1,534.80		$	—	$	2,905.40
	Total liabilities measured at fair value, reported as:
	Other accrued liabilities	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total liabilities measured at fair value	$	—	$	(3.4	)	$	—	$	(3.4	)
	________________________________
	(1)	Balance includes $88.1 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
	(2)	Balance relates to the restricted investments measured at fair market value of the Company's India Gratuity Trust.
	(3)	Balance relates to investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.
		Fair Value Measurements at December 31, 2012 Using:
		Quoted Prices in		Significant Other			Significant Other
		Active Markets For		Observable			Unobservable
		Identical Assets		Remaining Inputs			Remaining Inputs
		(Level 1)		(Level 2)			(Level 3)		Total
	Assets measured at fair value:
	Available-for-sale securities:
	Asset-backed securities	$	—	$	226.4		$	—	$	226.4
	Certificates of deposit	—		42.5			—		42.5
	Commercial paper	—		22.4			—		22.4
	Corporate debt securities	—		535.6			—		535.6
	Foreign government debt securities	—		5			—		5
	Government-sponsored enterprise obligations	254.9		16.1			—		271
	Money market funds (1)	1,145.20		—			—		1,145.20
	Mutual funds (2)	1		2			—		3
	Publicly-traded equity securities	2.9		—			—		2.9
	U.S. government securities	275.9		218.6			—		494.5
	Total available-for-sale securities	1,679.90		1,068.60			—		2,748.50
	Trading securities in mutual funds (3)	12.6		—			—		12.6
	Derivative assets:
Foreign exchange contracts	—		3.5			—		3.5
Total assets measured at fair value	$	1,692.50	$	1,072.10		$	—	$	2,764.60
Liabilities measured at fair value:
Derivative liabilities:
Foreign exchange contracts	$	—	$	0.1		$	—	$	0.1
Total liabilities measured at fair value	$	—	$	0.1		$	—	$	0.1
Total assets measured at fair value, reported as:
Cash equivalents	$	1,048.70	$	177.2		$	—	$	1,225.90
Restricted investments	103.6		2			—		105.6
Short-term investments	224.4		217.1			—		441.5
Long-term investments	315.8		672.3			—		988.1
Prepaid expenses and other current assets	—		3.5			—		3.5
Total assets measured at fair value	$	1,692.50	$	1,072.10		$	—	$	2,764.60
Total liabilities measured at fair value, reported as:
Other accrued liabilities	$	—	$	0.1		$	—	$	0.1
Total liabilities measured at fair value	$	—	$	0.1		$	—	$	0.1
________________________________
(1)	Balance includes $102.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
(2)	Balance relates to the restricted investments measured at fair market value of the Company's India Gratuity Trust.
(3)	Balance relates to investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.
The Company's Level 2 available-for-sale fixed income securities are priced using quoted market prices for similar instruments or non-binding market prices that are corroborated by observable market data. The Company uses inputs such as actual trade data, benchmark yields, broker/dealer quotes, or alternative pricing sources with reasonable levels of price transparency which are obtained from quoted market prices, independent pricing vendors, or other sources, to determine the ultimate fair value of these assets. The Company's policy is to recognize asset or liability transfers among Level 1, Level 2, and Level 3 at the beginning of the quarter in which a change in circumstance resulted in the transfer. During the three and nine months ended September 30, 2013, the Company transferred approximately $287.4 million of government agency bonds within government-sponsored enterprise obligations from Level 1 to Level 2 primarily due to the use of additional valuation inputs more appropriately classified as Level 2 inputs. During the three and nine months ended September 30, 2013, the Company had no transfers to Level 3. During the three and nine months ended September 30, 2012, the Company had no transfers between levels of the fair value hierarchy of its assets or liabilities measured at fair value.
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Certain of the Company's assets, including intangible assets, goodwill, and privately-held investments, are measured at fair value on a nonrecurring basis if impairment is indicated. Privately-held investments, which are normally carried at cost, are measured at fair value due to events and circumstances that the Company identified as significantly impacting the fair value of investments. The Company estimated the fair value of its privately-held investments using an analysis of the financial condition and near term prospects of the investee, including recent financing activities and their capital structure. During the three and nine months ended September 30, 2013, privately-held investments with a carrying value of $4.3 million and $4.7 million, respectively, were measured at fair value, resulting in an impairment charge of $2.1 million and $2.5 million, respectively. As of September 30, 2013, these investments were classified as Level 3 assets due to the absence of quoted market prices and inherent lack of liquidity. As of December 31, 2012, the Company had no assets measured at fair value on a nonrecurring basis.
As of September 30, 2013 and December 31, 2012, the Company had no liabilities measured at fair value on a nonrecurring basis.
Assets and Liabilities Not Measured at Fair Value
The carrying amounts of the Company's accounts receivable, financing receivables, accounts payable, and other accrued liabilities approximate fair value due to their short maturities. The fair value of the Company’s long-term debt is disclosed in Note 10, Long-Term Debt and Financing, and was determined using quoted market prices (Level 1).

Derivative_Instruments_Notes

Derivative Instruments (Notes)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative instruments	'
	Derivative Instruments
	The Company uses derivatives to partially offset its market exposure to fluctuations in certain foreign currencies and does not enter into derivatives for speculative or trading purposes.
	The notional amount of the Company's foreign currency derivatives are summarized as follows (in millions):
		As of
		September 30,		December 31,
		2013		2012
	Cash flow hedges	$	127.2	$	85.8
	Non-designated derivatives	153.5		112.8
	Total	$	280.7	$	198.6
	Cash Flow Hedges
	The Company can use foreign currency forward or option contracts to hedge certain forecasted foreign currency transactions relating to cost of services and operating expenses. The derivatives are intended to hedge the U.S. Dollar equivalent of the Company's planned cost of services and operating expenses denominated in foreign currencies. These derivatives are designated as cash flow hedges. Execution of these cash flow hedge derivatives typically occurs every month with maturities of one year or less. The effective portion of the derivative's gain or loss is initially reported as a component of accumulated other comprehensive income, and upon occurrence of the forecasted transaction, is subsequently reclassified into the cost of services or operating expense line item to which the hedged transaction relates. The Company records any ineffectiveness of the hedging instruments in other expense, net, in its Condensed Consolidated Statements of Operations. Cash flows from such hedges are classified as operating activities. All amounts within other comprehensive income are expected to be reclassified into earnings within the next twelve months.
	As of September 30, 2013 and December 31, 2012, the total fair value of the Company’s derivative assets recorded in other current assets on the Condensed Consolidated Balance Sheets was $2.8 million and $3.5 million, respectively. As of September 30, 2013 and December 31, 2012, the total fair value of the Company’s derivative liabilities recorded in other accrued liabilities on the Condensed Consolidated Balance Sheets was $3.4 million and $0.1 million, respectively.
	During the three and nine months ended September 30, 2013, the Company recognized a loss of $0.4 million and $4.2 million, respectively, in accumulated other comprehensive income for the effective portion of its derivative instruments and reclassified a loss of $1.4 million and a gain of $0.6 million, respectively, from other comprehensive income to operating expense in the Condensed Consolidated Statements of Operations. During the three and nine months ended September 30, 2012, the Company recognized a gain of $5.7 million and $6.5 million, respectively, in accumulated other comprehensive income for the effective portion of its derivative instruments and reclassified a loss of $3.2 million and $8.7 million, respectively, from other comprehensive income to operating expense in the Condensed Consolidated Statements of Operations.
	The ineffective portion of the Company's derivative instruments recognized in its Condensed Consolidated Statements of Operations was not material during the three and nine months ended September 30, 2013 and September 30, 2012.
	Non-Designated Derivatives
	The Company also uses foreign currency forward contracts to mitigate variability in gains and losses generated from the remeasurement of certain monetary assets and liabilities denominated in foreign currencies. These derivatives do not qualify for special hedge accounting treatment. These derivatives are carried at fair value with changes recorded in other expense, net, in the Condensed Consolidated Statements of Operations. Changes in the fair value of these derivatives are largely offset by re-measurement of the underlying assets and liabilities. Cash flows from such derivatives are classified as operating activities. The derivatives have maturities within two months.
	During the three and nine months ended September 30, 2013, the Company recognized a net gain of $0.9 million and $1.0 million, respectively, on non-designated derivative instruments within other expense, net in its Condensed Consolidated Statements of Operations. During the three and nine months ended September 30, 2012, the Company recognized a net gain of $0.3 million and $0.5 million, respectively, within other expense, net, in its Condensed Consolidated Statements of Operations.
	Offsetting of Derivatives
	The Company presents its derivative assets and derivative liabilities on a gross basis in the Condensed Consolidated Balance Sheets. However, under agreements containing provisions on netting with certain counterparties of foreign exchange contracts, subject to applicable requirements, the Company is allowed to net-settle transactions on the same date in the same currency, with a single net amount payable by one party to the other. As of September 30, 2013 and December 31, 2012, the potential effect of rights of setoff associated with derivative instruments would be an offset to both assets and liabilities of $1.1 million and $0.1 million, respectively. The resulting net derivative assets and derivative liabilities of the potential offset impact are $1.7 million and $2.3 million as of September 30, 2013, respectively. The resulting net derivative assets are $3.4 million and not material for derivative liabilities as of December 31, 2012. The Company is neither required to pledge nor entitled to receive cash collateral related to these derivative transactions.

Goodwill_and_Purchased_Intangi

Goodwill and Purchased Intangible Assets (Notes)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and purchased intangible assets	'
	Goodwill and Purchased Intangible Assets
	Goodwill
	The following table presents the goodwill activity allocated to the Company's reportable segments during the nine months ended September 30, 2013 (in millions):
		PSD			SSD			Total
	Balance as of December 31, 2012	$	1,866.30		$	2,191.50		$	4,057.80
	Reclassifications	(249.6		)	249.6			—
	Foreign currency translation adjustment	(0.1		)	—			(0.1		)
	Balance as of September 30, 2013	$	1,616.60		$	2,441.10		$	4,057.70
	During the third quarter of 2013, the Company realigned certain products from its PSD segment to its SSD segment resulting in a reclassification of goodwill of $70.6 million related to its acquisition of Contrail. In addition, goodwill of $179.0 million associated with security products previously reported under PSD was reclassified to SSD in connection with the Company's product realignment of all security products during the first quarter of 2013. See Note 13, Segments, for further discussion of the Company's product realignments. Goodwill was reclassified based on the relative fair value allocation of the reporting units affected. There were no impairments to goodwill during the three and nine months ended September 30, 2013 and September 30, 2012.
	Purchased Intangible Assets
	The Company’s purchased intangible assets were as follows (in millions):
		Gross			Accumulated			Impairments and			Net
					Amortization			Other Charges
	As of September 30, 2013
	Intangible assets with finite lives:
	Technologies and patents	$	581.4		$	(445.2	)	$	(30.5	)	$	105.7
	Customer contracts, support agreements, and	74.3			(61.9		)	(2.2		)	10.2
	related relationships
	Other	18.8			(18.8		)	—			—
	Total purchased intangible assets	$	674.5		$	(525.9	)	$	(32.7	)	$	115.9
	As of December 31, 2012
	Intangible assets with finite lives:
	Technologies and patents	$	554.1		$	(425.0	)	$	(30.5	)	$	98.6
	Customer contracts, support agreements, and	74.3			(59.2		)	(2.2		)	12.9
	related relationships
	Other	18.8			(18.8		)	—			—
	Total intangible assets with finite lives	647.2			(503.0		)	(32.7		)	111.5
	IPR&D with indefinite lives	17.4			—			—			17.4
	Total purchased intangible assets	$	664.6		$	(503.0	)	$	(32.7	)	$	128.9
	The purchased intangible assets balance as of September 30, 2013, includes intangible assets acquired through the acquisition completed during the first quarter of 2013. Refer to Note 3, Business Combinations, for further details.
	During the third quarter of 2013, $17.4 million of acquired IPR&D accounted for as indefinite lived assets reached technological feasibility and were reclassified as amortizable finite-lived assets. Amortization of purchased intangible assets included in cost of product revenues and operating expenses totaled $7.6 million and $9.0 million for the three months ended September 30, 2013 and September 30, 2012, respectively, and $22.8 million and $25.1 million for the nine months ended September 30, 2013 and September 30, 2012, respectively.
	In connection with the 2012 Restructuring Plan discussed in Note 9, Restructuring and Other Charges, the Company assessed the value and remaining useful life of certain intangible assets and determined intangible assets of $5.4 million were impaired and such assets were written-down to their fair value of zero during the three and nine months ended September 30, 2012. These assets were measured at fair value primarily using discounted cash flow projections. Additionally, other intangible assets of $10.7 million were no longer utilized. As a result, the Company recorded $16.1 million in charges related to these items during the three and nine months ended September 30, 2012, which were included in cost of revenues in the Condensed Consolidated Statements of Operations. There were no impairment charges to purchased intangible assets during the three and nine months ended September 30, 2013.
	As of September 30, 2013, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):
	Years Ending December 31,	Amount
	Remainder of 2013	$	9.1
	2014	36.2
	2015	32.6
	2016	18.5
	2017	10.5
	Thereafter	9
	Total	$	115.9

Other_Financial_Information_No

Other Financial Information (Notes)	9 Months Ended
	Sep. 30, 2013
Other Financial Information [Abstract]	'
Other financial information	'
	Other Financial Information
	Inventories, Net
	The Company purchases and holds inventory to provide adequate component supplies over the life of the underlying products. The majority of the Company's inventory is production components. Inventories, net, are reported within prepaid expenses and other current assets on the Condensed Consolidated Balance Sheets and consisted of the following (in millions):
		As of
		September 30,			December 31,
		2013			2012
	Inventories, net:
	Production materials	$	54.4		$	54.6
	Finished goods	0.8			4.1
	Total inventories, net	$	55.2		$	58.7
	In connection with the 2012 Restructuring Plan discussed in Note 9, Restructuring and Other Charges, the Company recorded a $36.3 million charge during the three and nine months ended September 30, 2012, to cost of revenues for component inventory held in excess of forecasted demand.
	Warranties
	The Company accrues for warranty costs as part of its cost of revenues based on associated material costs, labor costs for customer support, and overhead at the time revenue is recognized. This provision is reported as accrued warranty within current liabilities on the Condensed Consolidated Balance Sheets. Changes in the Company’s warranty reserve during the nine months ended September 30, 2013 were as follows (in millions):
	Balance as of December 31, 2012	$	29.7
	Provisions made during the period, net	20.9
	Adjustments related to pre-existing warranties	(0.7		)
	Actual costs incurred during the period	(21.3		)
	Balance as of September 30, 2013	$	28.6
	Deferred Revenue
	Details of the Company's deferred revenue, as reported on the Condensed Consolidated Balance Sheets, were as follows (in millions):
		As of
		September 30,			December 31,
		2013			2012
	Deferred product revenue:
	Undelivered product commitments and other product deferrals	$	212.2		$	256.9
	Distributor inventory and other sell-through items	133.9			138.4
	Deferred gross product revenue	346.1			395.3
	Deferred cost of product revenue	(66.3		)	(99.4		)
	Deferred product revenue, net	279.8			295.9
	Deferred service revenue	741.4			627.5
	Total	$	1,021.20		$	923.4
	Reported as:
	Current	$	731.9		$	693.5
	Long-term	289.3			229.9
	Total	$	1,021.20		$	923.4
	Deferred product revenue represents unrecognized revenue related to shipments to distributors that have not sold through to end-users, undelivered product commitments, and other shipments that have not met all revenue recognition criteria. Deferred product revenue is recorded net of the related costs of product revenue. Deferred service revenue represents billable amounts for service contracts, which include technical support, hardware and software maintenance, professional services, and training, for which services have not been rendered.
	Other Expense, Net
	Other expense, net, consisted of the following (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Interest income	$	2.3		$	2.6		$	6.1		$	8.3
	Interest expense	(14.2		)	(12.8		)	(43.4		)	(40.6		)
	Other	4.4			6.2			7.1			6.7
	Other expense, net	$	(7.5	)	$	(4.0	)	$	(30.2	)	$	(25.6	)
	Interest income primarily includes interest earned on the Company’s cash, cash equivalents, and investments. Interest expense primarily includes interest, net of capitalized interest expense from long-term debt and customer financing arrangements. Other typically consists of investment and foreign exchange gains and losses and other non-operational income and expense items. During the three and nine months ended September 30, 2013, the Company recognized a net gain in Other of $3.6 million and $4.9 million, respectively, related to the Company's privately-held investments. During the three and nine months ended September 30, 2012, Other was primarily comprised of a net gain of $5.8 million and $6.6 million, respectively, related to the Company's privately-held investments.

Restructuring_and_Other_Charge

Restructuring and Other Charges (Notes)	9 Months Ended
	Sep. 30, 2013
Restructuring Charges [Abstract]	'
Restructuring and other charges	'
	Restructuring and Other Charges
	Restructuring charges are based on the Company's restructuring plans that were committed to by management. These restructuring charges are recorded within cost of revenues or restructuring and other charges in the Condensed Consolidated Statements of Operations, as applicable. Any changes in the estimates of executing the approved plans are reflected in the Company's results of operations. Restructuring liabilities are reported within other accrued liabilities and other long-term liabilities on the Condensed Consolidated Balance Sheets.
	During the third quarter of 2013, the Company initiated a restructuring plan (the "2013 Restructuring Plan") to continue to improve its cost structure and rationalize its product portfolio and rebalance its investments. The 2013 Restructuring Plan consists of workforce reductions, contract terminations, and project cancellations. The Company recorded $4.5 million in severance costs and $6.6 million of contract termination and project cancellation charges related to the 2013 Restructuring Plan during the three months ended September 30, 2013. The Company expects to incur charges related to this plan through the first half of 2014.
	During 2012, the Company initiated a restructuring plan (the "2012 Restructuring Plan") to bring its cost structure more in line with its long-term financial and strategic model. The 2012 Restructuring Plan consists of workforce reductions, facility consolidations and closures, and supply chain and procurement efficiencies. During the three and nine months ended September 30, 2013, the Company continued to implement restructuring activities under the 2012 Restructuring Plan and recorded $1.0 million and $17.6 million, respectively, in charges for severance costs, facility consolidations and closures, and contract terminations. The Company recorded $29.1 million in severance costs and $0.4 million of other charges related to the 2012 Restructuring Plan during the three and nine months ended September 30, 2012. In connection with these restructuring activities, the Company also recorded certain inventory and intangible asset impairment charges totaling $52.4 million to cost of revenues during the third quarter of 2012. Under the 2012 Restructuring Plan, total costs incurred through September 30, 2013 were $111.0 million, of which $56.9 million was recorded within cost of revenues and $54.1 million was recorded within restructuring and other charges in the Condensed Consolidated Statements of Operations. The restructuring activities related to this plan are substantially complete.
	During 2011, the Company implemented a restructuring plan (the "2011 Restructuring Plan") in an effort to better align its business operations with the current market and macroeconomic conditions. The 2011 Restructuring Plan consisted of certain workforce reductions, facility closures and to a lesser extent, contract terminations. The Company recorded the majority of the restructuring charges associated with the 2011 Restructuring Plan during the years ended 2012 and 2011 and recorded a severance-related reversal of $0.1 million during the nine months ended September 30, 2013. As of September 30, 2013, the remaining restructuring liability under this plan relates to facility charges, which are expected to be completed by March 2018.
	The following table presents restructuring and other charges included in cost of revenues and restructuring and other charges in the Condensed Consolidated Statements of Operations under the Company's restructuring plans (in millions):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013			2012
	Severance	$	3.8		$	29.1	$	9		$	33.4
	Facilities	(0.8		)	1.5		9.5			3.2
	Contract terminations and other	9.1			52.8		10.1			52
	Total	$	12.1		$	83.4	$	28.6		$	88.6
	Reported as:
	Cost of revenues	$	6.1		$	52.4	$	7.6		$	52.4
	Restructuring and other charges	6			31		21			36.2
	Total	$	12.1		$	83.4	$	28.6		$	88.6
	The following table provides a summary of changes in the restructuring liability related to the Company's plans during the nine months ended September 30, 2013 (in millions):
		December 31,			Charges		Cash			Non-cash			September 30,
		2012					Payments			Settlements and			2013
										Other
	Severance	$	10.6		$	9	$	(14.8	)	$	(0.1	)	$	4.7
	Facilities	5.2			9.5		(4.4		)	(4.1		)	6.2
	Contract terminations and other	2.4			10.1		(5.5		)	(0.6		)	6.4
	Total	$	18.2		$	28.6	$	(24.7	)	$	(4.8	)	$	17.3
	In connection with the restructuring plans discussed above, the Company expects to record aggregate future charges of approximately $11.0 million related to workforce reductions and contract terminations through the first half of 2014.

LongTerm_Debt_and_Financing_No

Long-Term Debt and Financing (Notes)	9 Months Ended
	Sep. 30, 2013
Debt Instruments [Abstract]	'
Long-term debt and financing	'
	Long-Term Debt and Financing
	Long-Term Debt
	The following table summarizes the Company's long-term debt (in millions, except percentages):
		As of September 30, 2013
		Amount			Effective Interest
					Rates
	Senior notes:
	3.10% fixed-rate notes, due 2016 ("2016 Notes")	$	300		3.12	%
	4.60% fixed-rate notes, due 2021 ("2021 Notes")	300			4.63	%
	5.95% fixed-rate notes, due 2041 ("2041 Notes")	400			6.01	%
	Total senior notes	1,000.00
	Unaccreted discount	(0.7		)
	Total	$	999.3
	The effective interest rates for the 2016 Notes, 2021 Notes, and 2041 Notes (collectively the “Notes”) include the interest on the Notes, accretion of the discount, and amortization of issuance costs. As of September 30, 2013 and December 31, 2012, the estimated fair value of the Notes included in long-term debt in the Condensed Consolidated Balance Sheets was approximately $1,022.3 million and $1,090.7 million, respectively, based on quoted market prices (Level 1). As of September 30, 2013, the Company was in compliance with all of its debt covenants.
	Customer Financing Arrangements
	The Company provides distribution partners access to extended financing arrangements for certain end-user customers that require longer payment terms than those typically provided by the Company through factoring accounts receivable to third-party financing providers. The program does not and is not intended to affect the timing of the Company's revenue recognition. Under the financing arrangements, proceeds from the financing provider are due to the Company 30 days from the sale of the receivable. In these transactions with the financing provider, the Company surrenders control over the transferred assets. The factored accounts receivable are isolated from the Company and put beyond the reach of creditors, even in the event of bankruptcy. The Company does not maintain effective control over the transferred assets through obligations or rights to redeem, transfer, or repurchase the receivables after they have been transferred.
	Pursuant to the financing arrangements for the sale of receivables, the Company sold net receivables of $241.4 million and $198.8 million during the three months ended September 30, 2013 and September 30, 2012, respectively, and $607.1 million and $482.0 million during the nine months ended September 30, 2013 and September 30, 2012, respectively.
	The Company received cash proceeds from the financing provider of $210.8 million and $156.7 million during the three months ended September 30, 2013 and September 30, 2012, respectively, and $579.2 million and $482.5 million during the nine months ended September 30, 2013 and September 30, 2012, respectively. As of September 30, 2013 and December 31, 2012, the amounts owed by the financing provider were $165.8 million and $147.6 million, respectively, and such amounts were recorded in accounts receivable on the Company’s Condensed Consolidated Balance Sheets.
	In addition, the Company provided guarantees for third-party financing arrangements extended to end-user customers, which have terms up to four years. The Company is liable for the aggregate unpaid payments to the third-party financing company in the event of customer default. As of September 30, 2013, the Company has not made any payments under these arrangements. Pursuant to these arrangements, the Company has guarantees for third-party financing arrangements of $32.2 million as of September 30, 2013.
	The portion of the receivable financed that has not been recognized as revenue is accounted for as a financing arrangement and is included in other accrued liabilities and other long-term liabilities in the Condensed Consolidated Balance Sheets. As of September 30, 2013 and December 31, 2012, the estimated cash received from the financing provider not recognized as revenue was $72.5 million and $30.7 million, respectively.

Equity_Notes

Equity (Notes)	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Equity	'
	Equity
	Stock Repurchase Activities
	In July 2013, the Company's Board of Directors (the "Board") approved a stock repurchase program that authorized the Company to repurchase up to $1.0 billion of its common stock from time to time at management's discretion. The authorization was in addition to the $1.0 billion stock repurchase program approved by the Board and announced in June 2012. As of September 30, 2013, there was $1.2 billion of authorized funds remaining under the Company's stock repurchase programs. In addition to repurchases under the Company’s stock repurchase programs, the Company also repurchases common stock from its employees in connection with the net issuance of shares to satisfy minimum tax withholding obligations for the vesting of certain stock awards.
	The Company repurchased and retired approximately 4.4 million and 17.0 million shares of its common stock under its stock repurchase programs at an average price of $20.92 and $19.32 per share for an aggregate purchase price of $92.9 million and $328.4 million during the three and nine months ended September 30, 2013, respectively. The Company repurchased and retired approximately 13.9 million and 21.3 million shares of its common stock under its stock repurchase programs at an average price of $18.00 and $18.60 per share for an aggregate purchase price of $250.0 million and $395.6 million during the three and nine months ended September 30, 2012, respectively. Repurchases associated with tax withholdings were not significant during the three and nine months ended September 30, 2013 and September 30, 2012.
	All shares of common stock repurchased under the Company's stock repurchase programs and from its employees in connection with tax withholdings have been retired. Future share repurchases under the Company’s stock repurchase programs will be subject to a review of the circumstances at that time and will be made from time to time in private transactions or open market purchases as permitted by securities laws and other legal requirements. The Company's stock programs may be discontinued at any time. See Note 17, Subsequent Events, for discussion of the Company's stock repurchase activity subsequent to September 30, 2013.
	Accumulated Other Comprehensive Income, Net of Tax
	The components of accumulated other comprehensive income, net of related taxes, during the nine months ended September 30, 2013 were as follows (in millions):
		Unrealized			Unrealized			Foreign			Total
		Gains (Losses)			Gains (Losses)			Currency
		on Available-for-			on Cash Flow			Translation
		Sale Securities(1)			Hedges(2)			Adjustments
	Balance as of December 31, 2012	$	2.1		$	3		$	(0.4	)	$	4.7
	Other comprehensive gain (loss) before reclassifications	70.8			(1.8		)	(5.4		)	63.6
	Amount reclassified from accumulated other	(0.8		)	(0.9		)	—			(1.7		)
	comprehensive income
	Other comprehensive gain (loss)	70			(2.7		)	(5.4		)	61.9
	Balance as of September 30, 2013	$	72.1		$	0.3		$	(5.8	)	$	66.6
	________________________________
	(1)	The reclassifications out of accumulated comprehensive income during the nine months ended September 30, 2013 for realized gains on available-for-sale securities of $0.8 million are included in other expense, net, in the Condensed Consolidated Statements of Operations.
	(2)	The reclassifications out of accumulated comprehensive income during the nine months ended September 30, 2013 for realized gains on cash flow hedges are included within cost of revenues of $0.5 million and sales and marketing of $1.3 million and for realized losses of $0.9 million within research and development for which the hedged transactions relate in the Condensed Consolidated Statements of Operations.
	The following table presents the taxes related to each component of other comprehensive income (in millions):
		Three Months Ended September 30, 2013									Nine Months Ended September 30, 2013
		Gross			Income Tax			Net			Gross			Income Tax			Net
		Amount			(Provision)			Amount			Amount			(Provision)			Amount
					Benefit									Benefit
	Available-for-sale securities:
	Change in unrealized gains (losses) on	$	101.6		$	(36.4	)	$	65.2		$	111.2		$	(40.4	)	$	70.8
	available-for-sale securities
	Reclassification adjustment for realized net	(0.4		)	0.1			(0.3		)	(1.1		)	0.3			(0.8		)
	gains on available-for-sale securities
	included in net income
	Net change in unrealized gains (losses)	101.2			(36.3		)	64.9			110.1			(40.1		)	70
	on available-for-sale securities
	Cash flow hedges:
	Change in unrealized (losses) gains on cash	(0.4		)	1.1			0.7			(4.2		)	2.4			(1.8		)
	flow hedges
	Reclassification adjustment for realized net	1.4			(0.8		)	0.6			(0.6		)	(0.3		)	(0.9		)
	losses (gains) on cash flow hedges
	included in net income
	Net change in unrealized gains (losses)	1			0.3			1.3			(4.8		)	2.1			(2.7		)
	on cash flow hedges
	Change in foreign currency adjustments	4.1			—			4.1			(5.4		)	—			(5.4		)
	Other comprehensive income	$	106.3		$	(36.0	)	$	70.3		$	99.9		$	(38.0	)	$	61.9
	Taxes related to each component of other comprehensive income were not material for the three and nine months ended September 30, 2012.

Employee_Benefit_Plans_Notes

Employee Benefit Plans (Notes)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Employee benefit plans	'
	Employee Benefit Plans
	Share-Based Compensation Plans
	The Company’s share-based compensation plans include the 2006 Equity Incentive Plan (the “2006 Plan”), the 2000 Nonstatutory Stock Option Plan (the “2000 Plan”), the Amended and Restated 1996 Stock Plan (the “1996 Plan”), various equity incentive plans assumed through acquisitions, and the 2008 Employee Stock Purchase Plan (the "ESPP"). Under these plans, the Company has granted (or in the case of acquired plans assumed) stock options, restricted stock units ("RSUs"), restricted stock awards ("RSAs"), and performance share awards ("PSAs").
	The 2006 Plan was adopted and approved by the Company’s stockholders in May 2006. To date, the Company's stockholders have approved a share reserve of 149.5 million shares of common stock plus the addition of any shares subject to options under the 2000 Plan and the 1996 Plan that were outstanding as of May 18, 2006, and that subsequently expire unexercised, up to a maximum of an additional 75.0 million shares. As of September 30, 2013, the 2006 Plan had 46.8 million shares subject to currently outstanding equity awards and 47.4 million shares available for future issuance.
	The ESPP was adopted in May 2008. To date, the Company's stockholders have approved a share reserve of 19.0 million shares of the Company's common stock for issuance under this plan. The ESPP permits eligible employees to acquire shares of the Company’s common stock at a 15% discount to the offering price (as determined in the ESPP) through periodic payroll deductions of up to 10% of base compensation, subject to individual purchase limits of 6,000 shares in any twelve-month period or $25,000 worth of stock, determined at the fair market value of the shares at the time the stock purchase option is granted, in one calendar year. As of September 30, 2013, approximately 12.8 million shares have been issued and 6.2 million shares remain available for future issuance under the ESPP.
	In connection with certain past acquisitions, the Company assumed stock options, RSU, and RSA awards under the assumed stock plans of the acquired companies and exchanged the assumed awards for Juniper's stock options, RSUs, and RSAs, respectively. No new stock options, RSUs, and RSAs can be granted under these plans. As of September 30, 2013, stock options, RSUs and RSAs representing approximately 5.5 million shares of common stock were outstanding under all awards assumed through the Company's acquisitions.
	Stock Option Activities
	The following table summarizes the Company’s stock option activity and related information as of and for the nine months ended September 30, 2013 (in millions, except for per share amounts and years):
		Outstanding Options
		Number of Shares			Weighted Average				Weighted Average		Aggregate
					Exercise Price				Remaining		Intrinsic
					per Share				Contractual Term		Value
									(In Years)
	Balance as of December 31, 2012	34.1			$	24.13
	Options granted	—			—
	Options canceled	(0.9	)		31.63
	Options exercised	(4.4	)		15.44
	Options expired	(3.1	)		28.28
	Balance as of September 30, 2013	25.7			$	24.87			2.7		$	34.3
	As of September 30, 2013:
	Vested and expected-to-vest options	25.2			$	24.95			2.6		$	31.7
	Exercisable options	22.1			$	25.07			2.2		$	19.8
	Aggregate intrinsic value represents the difference between the Company’s closing stock price on the last trading day of the period, which was $19.86 per share as of September 30, 2013, and the exercise price multiplied by the number of related options. The pre-tax intrinsic value of options exercised, representing the difference between the fair market value of the Company’s common stock on the date of exercise and the exercise price of each option, was $9.6 million and $24.0 million for the three and nine months ended September 30, 2013, respectively.
	Restricted Stock Unit, Restricted Stock Award, and Performance Share Award Activities
	The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the nine months ended September 30, 2013 (in millions, except per share amounts and years):
		Outstanding RSUs, RSAs, and PSAs
		Number of Shares			Weighted Average				Weighted Average		Aggregate
					Grant-Date Fair				Remaining		Intrinsic
					Value per Share				Contractual Term		Value
									(In Years)
	Balance as of December 31, 2012	26.8			$	27.76
	RSUs granted	9.7			20.29
	PSAs granted (*)	2.2			21.27
	RSUs vested	(4.6	)		27.74
	PSAs vested	(1.1	)		28.27
	RSAs vested	(1.1	)		19.59
	RSUs canceled	(2.5	)		23.14
	PSAs canceled	(2.8	)		29.94
	Balance as of September 30, 2013	26.6			$	25.05			1.3		$	529
	As of September 30, 2013:
	Vested and expected-to-vest RSUs, RSAs,	22.8			$	23.57			1.1		$	453.7
	and PSAs
	________________________________
	(*)	The number of shares subject to PSAs granted represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The aggregate number of shares subject to these PSAs that would be issued if performance goals determined by the Compensation Committee are achieved at target is 1.1 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 2.2 million shares.
	Employee Stock Purchase Plan
	The Company's ESPP is implemented in a series of offering periods, each six months in duration, or a shorter period as determined by the Board. Employees purchased approximately 1.5 million and 3.3 million shares of common stock through the ESPP at an average per share price of $18.42 and $16.53 for the three and nine months ended September 30, 2013, respectively, and 1.9 million and 3.6 million shares at an average per share price of $14.90 and $16.26 for the three and nine months ended September 30, 2012, respectively.
	Share-Based Compensation Expense
	The weighted-average assumptions used and the resulting estimates of fair value for stock options and ESPP were as follows:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Stock Options:
	Volatility	—		46%		—		46%
	Risk-free interest rate	—		0.70%		—		0.80%
	Expected life (years)	—		4.2		—		4.2
	Dividend yield	—		—		—		—
	Weighted-average fair value per share	—		$6.89		—		$8.46
	ESPP:
	Volatility	35%		42%		36%		47%
	Risk-free interest rate	0.10%		0.10%		0.10%		0.10%
	Expected life (years)	0.5		0.5		0.5		0.5
	Dividend yield	—		—		—		—
	Weighted-average fair value per share	$5.47		$4.77		$5.54		$5.53
	Share-based compensation expense associated with stock options, ESPP, RSUs, RSAs, and PSAs was recorded in the following cost and expense categories in the Company's Condensed Consolidated Statements of Operations (in millions):
	Three Months Ended September 30,								Nine Months Ended September 30,
	2013				2012				2013			2012
Cost of revenues - Product	$	1.4			$	1.2			$	3.5		$	3.3
Cost of revenues - Service	3.4				3.8				11.5			13.3
Research and development	36.6				26.1				93.2			80.4
Sales and marketing	20.4				21.4				53			64.3
General and administrative	7.5				6.6				19.5			24.7
Total	$	69.3			$	59.1			$	180.7		$	186
The following table summarizes share-based compensation expense by award type (in millions):
	Three Months Ended September 30,								Nine Months Ended September 30,
	2013				2012				2013			2012
Stock options	$	7.7			$	14.3			$	24.9		$	47.1
RSUs, RSAs, and PSAs	57.7				40.1				144			123.3
ESPP	3.9				4.7				11.8			15.6
Total	$	69.3			$	59.1			$	180.7		$	186
The following table presents unrecognized compensation cost, adjusted for estimated forfeitures, recognized over a weighted-average period related to unvested stock options, RSUs, RSAs, and PSAs as of September 30, 2013 (in millions, except years):
	Unrecognized				Weighted Average
	Compensation Cost				Period
					(In Years)
Stock options	$	41.4			2
RSUs, RSAs, and PSAs	$	326.1			2

Segments_Notes

Segments (Notes)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segments	'
	Segments
	The Company’s chief operating decision maker (“CODM”) allocates resources and assesses performance based on financial information of the Company’s divisions. In the third quarter of 2013, the Company realigned certain products from its PSD segment to its SSD segment in connection with its acquisition of Contrail. In addition, in the first quarter of 2013, the Company consolidated operational oversight and management of all security products within the SSD segment. As a result of this change, security products previously reported in the PSD segment (including the Branch SRX, Branch Firewall, and J Series product families) are now reported in the SSD segment. The Company reclassified the segment data for the prior period to conform to the current period's presentation.
	The Company’s PSD segment primarily offers scalable routing and switching products that are used in service provider, enterprise, and public sector networks to control and direct network traffic from data centers, core, edge, aggregation, campus, Wide Area Networks ("WANs"), and customer premise equipment level. The Company's PSD segment consists of routing and switching products and services. Routing products and services include the ACX, E, M, MX, PTX, and T Series product families. Switching products and services primarily consist of the EX Series and wireless local area network solutions, as well as QFabric™.
	The Company's SSD segment offers solutions that meet a broad array of our customers’ priorities, from protecting the users, applications and data on the network to providing network services across a distributed infrastructure. The SSD segment primarily consists of security, software, management, virtualization, routing products and services. Security includes firewalls (both JUNOS-based SRX and Screen OS-based firewalls), Firefly, virtual private network systems and appliances, secure socket layer virtual private network appliances, intrusion detection and prevention appliances, wide area network optimization platforms, Junos Pulse, and J Series. Software and services for the mobile and wireline network edge include traffic flow monitoring, dynamic application and subscriber awareness, and next generation network addressing. Management and virtualization products include Junosphere, Junos SDK, JunosV App Engine and the network management platform, Junos Space. In the third quarter of 2013, the Company announced the availability of Juniper Networks Contrail, a standards-based and highly scalable network virtualization and intelligence solution for software-defined networks for enterprises and service providers.
	The CODM does not allocate to the Company's business segments certain operating expenses managed separately at the corporate level. Direct costs and operating expenses, such as standard cost of goods sold, research and development, and product marketing expenses, are generally applied to each segment. Indirect costs, such as manufacturing overhead and other cost of revenues, are allocated based on factors including headcount, usage, and revenue. Segment contribution margin provides supplemental data on operational performance and is comprised of these direct costs and operating expenses, as well as these indirect costs. Corporate unallocated expenses include: sales, marketing, general and administrative costs, share-based compensation, amortization of purchased intangible assets, restructuring and other charges, gains or losses on equity investments, other expense, net, income taxes, and certain other charges. Segment contribution margin excludes these corporate unallocated expenses.
	The following table summarizes financial information for each segment used by the CODM (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Net revenues:
	PSD	$	939.3		$	828.5		$	2,664.50		$	2,404.40
	SSD	246.3			289.8			731			820.2
	Total net revenues	$	1,185.60		$	1,118.30		$	3,395.50		$	3,224.60
	Segment contribution margin:
	PSD	$	424.1		$	318.9		$	1,151.70		$	910.9
	SSD	95.2			137			289.8			357.2
	Total segment contribution margin	$	519.3		$	455.9		$	1,441.50		$	1,268.10
	Corporate unallocated expenses(1)	$	(284.9	)	$	(266.5	)	$	(823.9	)	$	(794.2	)
	Amortization of purchased intangible assets(2)	(7.6		)	(9.0		)	(22.8		)	(25.1		)
	Share-based compensation expense	(69.3		)	(59.1		)	(180.7		)	(186.0		)
	Share-based payroll tax expense	(0.4		)	(0.1		)	(4.5		)	(1.0		)
	Restructuring and other charges(3)	(12.1		)	(83.4		)	(28.6		)	(88.6		)
	Acquisition and litigation charges	—			(0.3		)	(10.5		)	(1.3		)
	Other unallocated expense	—			5.3			—			5.3
	Total operating income	145			42.8			370.5			177.2
	Other expense, net	(7.5		)	(4.0		)	(30.2		)	(25.6		)
	Income before income taxes	$	137.5		$	38.8		$	340.3		$	151.6
	________________________________
	(1)	Amount includes unallocated costs for global functions such as sales, marketing, and general and administrative.
	(2)	Amount includes amortization expense of purchased intangible assets reported in cost of revenues and operating expenses.
	(3)	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.
	Depreciation expense allocated to the PSD segment was $26.8 million and $88.7 million in the three and nine months ended September 30, 2013, respectively, and $29.4 million and $84.8 million in the three and nine months ended September 30, 2012, respectively. Depreciation expense allocated to the SSD segment was $7.0 million and $23.6 million in the three and nine months ended September 30, 2013, respectively, and $9.6 million and $28.0 million in the three and nine months ended September 30, 2012, respectively.
	The Company attributes revenues to geographic region based on the customer’s ship-to location. The following table presents net revenues by geographic region (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Americas:
	United States	$	604.6		$	507.6		$	1,761.80		$	1,513.60
	Other	56.7			52.7			166.7			165.3
	Total Americas	661.3			560.3			1,928.50			1,678.90
	Europe, Middle East, and Africa	306.5			321.3			898			927.7
	Asia Pacific	217.8			236.7			569			618
	Total	$	1,185.60		$	1,118.30		$	3,395.50		$	3,224.60
	No customer accounted for greater than 10% of the Company's net revenues during the three and nine months ended September 30, 2013 or the three months ended September 30, 2012. During the nine months ended September 30, 2012, Verizon Communications, Inc. accounted for 10.2% of net revenues.
	The Company tracks assets by physical location. The majority of the Company’s assets, excluding cash and cash equivalents and investments, as of September 30, 2013 and December 31, 2012, were attributable to United States ("U.S.") operations. As of September 30, 2013 and December 31, 2012, gross property and equipment held in the U.S., as a percentage of total property and equipment, was approximately 84% and 83%, respectively. Although management reviews asset information on a corporate level and allocates depreciation expense by segment, the CODM does not review asset information on a segment basis.

Income_Taxes_Notes

Income Taxes (Notes)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income tax	'
	Income Taxes
	The Company's effective tax rate for the three and nine months ended September 30, 2013 was lower than the federal statutory rate of 35% and the effective tax rate for the same periods in 2012, primarily due to the benefit of the federal research and development ("R&D") credit, the Section 199 deduction for U.S. production activities and earnings in foreign jurisdictions, which are subject to lower tax rates.
	The effective tax rate for the three and nine months ended September 30, 2013 includes the effect of the following discrete items (in millions):
		Three Months Ended			Nine Months Ended
		30-Sep-13			30-Sep-13
	Section 199 deduction	$	(0.6	)	$	19.7
	Tax settlement with Internal Revenue Service (“IRS”)	$	—		$	27.8
	Reinstatement of the U.S. federal R&D tax credit	$	1		$	16.2
	During the nine months ended September 30, 2013, the Company completed a multi-year study for a Section 199 deduction for U.S. production activities, which provides for a special deduction for taxpayers engaged in qualified production activities within the U.S. Additionally, the Company finalized a closing agreement with the IRS covering specific matters related to the audit of the Company's federal income tax returns for tax years 2004 through 2006. On January 2, 2013, the American Taxpayer Relief Act of 2012 retroactively reinstated the U.S. federal R&D tax credit from January 1, 2012 to December 31, 2013.
	The effective tax rates for the three and nine months ended September 30, 2012, differ from the federal statutory rate of 35% primarily due to the effect of changes in foreign earnings coupled with the impact of the restructuring charges in the period. The effective rates for the periods do not reflect the benefit of the federal R&D credit, which expired on December 31, 2011.
	As of September 30, 2013, the total amount of gross unrecognized tax benefits was $144.0 million, of which $129.9 million, if recognized, would affect the Company's effective tax rate. The increase in the gross unrecognized tax benefits for the nine months ended September 30, 2013 of approximately $7.9 million is primarily due to the multi-year claim related to the U.S. production activities deduction partially offset by the IRS tax settlement referenced above.
	The Company engages in continuous discussions and negotiations with tax authorities regarding tax matters in various jurisdictions. There is a greater than remote likelihood that the balance of the gross unrecognized tax benefits will decrease by approximately $3.4 million within the next twelve months due to lapses of applicable statutes of limitation and the completion of tax review cycles in various tax jurisdictions.
	The Company is currently under examination by the IRS for the 2007 through 2009 tax years. The Company is also subject to separate ongoing examinations by the India tax authorities for the 2004 tax year, 2004 through 2008 tax years and the 2009 through 2010 tax years. The Company is not aware of any other examinations by tax authorities in any other major jurisdictions in which it files income tax returns as of September 30, 2013.
	In 2008, the Company received a proposed adjustment from the India tax authorities related to the 2004 tax year. In 2009, the India tax authorities commenced a separate investigation of our 2004 through 2008 tax returns and are disputing the Company's determination of taxable income due to the cost basis of certain fixed assets. The Company accrued $4.6 million in penalties and interest in 2009 related to this matter. The Company understands that in accordance with the administrative and judicial process in India, the Company may be required to make payments that are substantially higher than the amount accrued in order to ultimately settle this issue. The Company strongly believes that any assessment it may receive in excess of the amount accrued would be inconsistent with applicable India tax laws and intends to defend this position vigorously.
	The Company is pursuing all available administrative remedies relative to these matters. The Company believes that it has adequately provided for any reasonably foreseeable outcomes related to these proposed adjustments and the ultimate resolution of these matters is unlikely to have a material effect on its consolidated financial condition or results of operations; however there is still a possibility that an adverse outcome of these matters could have a material effect on its consolidated financial condition and results of operations. For more information, see Note 16, Commitments and Contingencies, under the heading “IRS Notices of Proposed Adjustments.”

Net_Income_per_Share_Notes

Net Income per Share (Notes)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Net income per share	'
	Net Income Per Share
	The Company computed basic and diluted net income per share as follows (in millions, except per share amounts):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Numerator:
	Net income	$	99.1	$	16.8	$	288	$	90.8
	Denominator:
	Weighted-average shares used to compute	501.5		521.2		503		525.4
	basic net income per share
	Dilutive effect of employee stock awards	7.1		3.3		7.7		4.9
	Weighted-average shares used to compute	508.6		524.5		510.7		530.3
	diluted net income per share
	Net income per share:
	Basic	$	0.2	$	0.03	$	0.57	$	0.17
	Diluted	$	0.19	$	0.03	$	0.56	$	0.17
	Basic net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding for the period. Diluted net income per share is computed using net income available to common stockholders and the weighted-average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Dilutive potential common shares consist of common shares issuable upon exercise of stock options, issuances of ESPP, and vesting of RSUs, RSAs, and PSAs. The Company includes the common shares underlying PSAs in the calculation of diluted net income per share when they become contingently issuable and excludes such shares when they are not contingently issuable.
	Potentially dilutive common shares of approximately 21.8 million and 22.3 million shares for the three and nine months ended September 30, 2013, respectively, and 36.8 million and 33.0 million shares for the three and nine months ended September 30, 2012, respectively, were excluded from the computation of diluted net income per share because their effect would be anti-dilutive.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and contingencies	'
	Commitments and Contingencies
	Commitments
	Operating Leases
	The Company leases its facilities and certain equipment under non-cancelable operating leases that expire at various dates through November 30, 2022. Certain leases require the Company to pay variable costs such as taxes, maintenance, and insurance and include renewal options and escalation clauses. Future minimum payments under the non-cancelable operating leases totaled $229.3 million as of September 30, 2013. Rent expense was $12.6 million and $39.9 million for the three and nine months ended September 30, 2013, respectively, and $15.7 million and $47.2 million for the three and nine months ended September 30, 2012, respectively.
	Purchase Commitments
	In order to reduce manufacturing lead times and ensure adequate component supply, the Company enters into agreements with contract manufacturers and certain suppliers to procure inventory based on the Company's requirements. A significant portion of the Company's purchase commitments arising from these agreements consists of firm and non-cancelable commitments. These purchase commitments totaled $553.3 million as of September 30, 2013. The Company establishes a liability in connection with these purchase commitments related to carrying charges, quantities in excess of our demand forecasts, or obsolete materials charges for materials purchased by contract manufacturers to meet the Company’s forecast or customer orders. As of September 30, 2013, the Company accrued $24.2 million based on its estimate of such charges.
	Long-Term Debt and Interest Payment on Long-Term Debt
	As of September 30, 2013, the Company held long-term debt consisting of senior notes with a carrying value of $999.3 million. Of these Notes, $300.0 million will mature in 2016 and bears interest at a fixed rate of 3.10%, $300.0 million will mature in 2021 and bears interest at a fixed rate of 4.60%, and $400.0 million will mature in 2041 and bears interest at a fixed rate of 5.95%. Interest on the Notes is payable semiannually. See Note 10, Long-Term Debt and Financing, for further discussion of the Company's long-term debt.
	Other Contractual Obligations
	As of September 30, 2013, other contractual obligations primarily consisted of $92.0 million in indemnity-related and service related escrows, as required in connection with certain asset purchases and acquisitions completed between 2005 and 2013, campus build-out obligations of $24.0 million, and other miscellaneous commitments of $16.1 million.
	Tax Liabilities
	As of September 30, 2013, the Company had $117.5 million included in long-term income taxes payable in the Condensed Consolidated Balance Sheets for unrecognized tax positions. At this time, the Company is unable to make a reasonably reliable estimate of the timing of payments related to this amount due to uncertainties in the timing of tax audit outcomes.
	Guarantees
	The Company enters into agreements with customers that contain indemnification provisions relating to potential situations where claims could be alleged that the Company’s products infringe the intellectual property rights of a third-party. The Company also has financial guarantees consisting of guarantees of product and service performance, guarantees related to third-party customer-financing arrangements, custom and duty guarantees, and standby letters of credit for certain lease facilities. As of September 30, 2013 and December 31, 2012, the Company had $42.4 million and $12.6 million, respectively, in financing guarantees, bank guarantees, and standby letters of credit related to these financial guarantees, of which $32.2 million in financing guarantees was recorded in other accrued liabilities and other long-term liabilities in the Condensed Consolidated Balance Sheets as of September 30, 2013. See Note 10, Long-Term Debt and Financing, for further discussion of the Company's third-party customer financing arrangements that contain guarantee provisions.
	Legal Proceedings
	The Company is involved in disputes, litigation, and other legal actions, including, but not limited to, the matters described below. The Company is aggressively defending its current litigation matters, and while there can be no assurances and the outcome of these matters is currently not determinable, the Company currently believes that there are no existing claims or proceedings that are likely to have a material adverse effect on its financial position. There are many uncertainties associated with any litigation and these actions or other third-party claims against the Company may cause the Company to incur costly litigation and/or substantial settlement charges. In addition, the resolution of any intellectual property litigation may require the Company to make royalty payments, which could adversely affect gross margins in future periods. If any of those events were to occur, the Company's business, financial condition, results of operations, and cash flows could be adversely affected. The actual liability in any such matters may be materially different from the Company's estimates, if any, which could result in the need to adjust the liability and record additional expenses. Unless otherwise noted below, during the period presented, we have not recorded any accrual for loss contingencies associated with such legal proceedings; determined that an unfavorable outcome is probable or reasonably possible; or determined that the amount or range of any possible loss is reasonably estimable.
	2013 Federal Securities Class Action
	On August 12, 2013, a purported securities class action lawsuit, captioned Warren Avery v. Juniper Networks, Inc., et al., Case No. 13-cv-3733-WHO, was filed in the United States District Court for the Northern District of California naming the Company and certain of its officers and directors as defendants. The complaint alleges that the defendants made false and misleading statements regarding the Company's revenues, business practices, and internal controls. The complaint purports to assert claims for violations of Sections 10 (b) and 20(a) of the Securities Exchange Act of 1934 and SEC Rule 10b-5 on behalf of those who purchased Juniper Networks' securities between April 24, 2012 and August 8, 2013, inclusive. Plaintiff seeks an unspecified amount of monetary damages on behalf of the purported class.
	2013 Shareholder Derivative Lawsuit
	On August 28, 2013, a purported shareholder derivative action captioned Washtenaw County Employees’ Retirement System v. Kriens, et al., Case No. 1-13-CV-252083, was filed in the Superior Court of the State of California, County of Santa Clara, naming certain of the Company's officers and directors as defendants. On October 17, 2013, the action was removed to the United States District Court for the Northern District of California, and was assigned Case No. 13-cv-04829-PSG. The Company is named only as a nominal defendant in the action. The complaint alleges that the defendants failed to implement adequate internal controls and compliance programs to prevent violations of the Foreign Corrupt Practices Act. The complaint purports to assert claims against the defendants for breach of fiduciary duties, abuse of control, and waste of corporate assets. The complaint seeks, among other relief, damages in an unspecified amount, restitution, and attorneys' fees and costs.
	Investigations
	The U.S. Securities and Exchange Commission and the U.S. Department of Justice are conducting investigations into possible violations by the Company of the U.S. Foreign Corrupt Practices Act. The Company is cooperating with these agencies regarding these matters. The Company is unable to predict the duration, scope or outcome of these investigations.
	2011 Federal Securities Class Action
	On August 15, 2011, a purported securities class action lawsuit, captioned City of Royal Oak Retirement System v. Juniper Networks, Inc., et al., Case No. 11-cv-04003-LHK, was filed in the United States District Court for the Northern District of California naming the Company and certain of its officers and directors as defendants. The complaint alleges that the defendants made false and misleading statements regarding the Company's business and prospects. Plaintiffs seek an unspecified amount of monetary damages on behalf of the purported class. On January 9, 2012 the Court appointed City of Omaha Police and Fire Retirement System and City of Bristol Pension Fund as lead plaintiffs. Lead plaintiffs allege that defendants made false and misleading statements about the Company's business and future prospects, and failed to adequately disclose the impact of certain changes in accounting rules. Lead plaintiffs purport to assert claims for violations of Sections 10 (b), 20(a) and 20A of the Securities Exchange Act of 1934 and SEC Rule 10b-5 on behalf of those who purchased or otherwise acquired Juniper Networks' common stock between July 20, 2010 and July 26, 2011, inclusive. On March 14, 2012, Defendants filed motions to dismiss lead plaintiffs' amended complaint. On July 23, 2012, the Court issued an order dismissing the action and giving lead plaintiffs leave to file an amended complaint. Lead plaintiffs filed their second amended complaint on August 20, 2012. Defendants filed a motion to dismiss the second amended complaint on September 17, 2012, and lead plaintiffs filed their opposition on October 22, 2012. Defendants filed their reply brief on November 8, 2012. On May 17, 2013, the Court granted Defendants' motion, dismissed the second amended complaint with prejudice, and entered judgment on Defendants' behalf.
	2011 California State Derivative Lawsuits
	Between August 22 and September 9, 2011, four purported shareholder derivative actions were filed in the Superior Court of the State of California, County of Santa Clara, naming certain of the Company's officers and directors as defendants. The Company is named only as a nominal defendant in the actions. The actions were consolidated as In re Juniper Networks, Inc. Shareholder Litigation, Case No. 1-11-CV-207701 (Lead Case), by order dated September 12, 2011. The complaints are generally based upon the disclosures and alleged omissions challenged in the securities class action. The complaints purport to assert claims against the defendants for breach of fiduciary duties, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets. The complaints seek, among other relief, damages in an unspecified amount, restitution, and attorneys' fees and costs. On March 8, 2012, the Company filed a motion to stay the action until resolution of the federal securities class action discussed above, and also filed a demurrer seeking to dismiss the action for the reason that plaintiffs lack standing. The plaintiffs filed oppositions to both motions on April 5, 2012. Defendants filed reply briefs on May 7, 2012. At a hearing on July 27, 2012, the Court ordered that the actions be stayed until such time as the federal court issues an order denying a motion to dismiss in the securities class action, City of Omaha Police and Fire Retirement System v. Juniper Networks, Inc. et al., Case No. CV-11-4003-LHK. The Court deferred deciding the demurrer pending the stay. On July 1, 2013, plaintiff Sanjay Israni and Defendants entered into a stipulation dismissing without prejudice the action Israni v. Kriens, et al., Case No. 1-11-CV-208042 (one of the actions comprising the consolidated action), and on July 8, 2013, the Court issued an order granting the stipulation and dismissing Israni v. Kriens, et al., without prejudice. On August 5, 2013, Defendants entered into a stipulation with the remaining plaintiffs dismissing without prejudice the consolidated action In re Juniper Networks, Inc. Shareholder Litigation, Case No. 1-11-CV-207701 (Lead Case), and on August 6, 2013, the Court issued an order granting the stipulation and dismissing the case without prejudice.
	2011 Federal Derivative Lawsuit
	On September 27, 2011 and December 28, 2011, two purported shareholder derivative actions, captioned Ratinova v. Johnson, et al., Case No. 11-cv-04792 and Lisa E. Coppola, ERA v. Johnson, et al., Case No. 11-cv-06667, respectively, were filed in the United States District Court for the Northern District of California naming certain of the Company's officers and directors as defendants. The Company is named only as a nominal defendant in the action. Like the state derivative actions, the federal derivative lawsuits are generally based upon the disclosures and alleged omissions challenged in the securities class action. The complaints purport to assert claims against the defendants for breach of fiduciary duties and unjust enrichment. The complaints seek, among other relief, damages in an unspecified amount, restitution, and attorneys' fees and costs. By order dated January 30, 2012, the Court consolidated the actions as In re Juniper Networks, Inc. Shareholder Derivative Litigation, Master File No. 11-cv-04792-LHK. On February 3, 2012, the parties filed a stipulation in which the parties requested that the Court stay the action until such time as the Court entered an order denying a motion to dismiss in the related federal securities class action described above. On February 6, 2012, the Court granted the parties' stipulation. On July 12, 2013, the parties filed a stipulation to voluntarily dismiss the case without prejudice. On July 13, 2013, the Court granted the parties' stipulation and entered an order dismissing the case without prejudice.
	IRS Notices of Proposed Adjustments
	The Company is currently under examination by the IRS for the 2007 through 2009 tax years.
	In 2013, the Company executed a closing agreement with the Appeals Division of the IRS related to its intercompany R&D cost sharing arrangement for the license of intangibles acquired in 2004, 2005 and 2006. The Company reached a final resolution with the IRS on all proposed adjustments for all tax years through 2006, which resulted in a settlement of approximately $19.6 million, including interest.

Subsequent_Events_Notes

Subsequent Events (Notes)	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent events	'
	Subsequent Events
	Stock Repurchases
	Subsequent to September 30, 2013, through the filing of this Report, the Company repurchased 0.3 million shares of its common stock, for $7.0 million at an average purchase price of $20.19 per share, under its stock repurchase programs. The 0.3 million shares were settled prior to the filing of this Report. Under its stock repurchase programs, the Company has $1.2 billion authorized funds remaining as of the filing date. Purchases under the Company's stock repurchase programs are subject to a review of the circumstances in place at the time and will be made from time to time as permitted by securities laws and other legal requirements. The Company's stock repurchase programs may be discontinued at any time.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Recent accounting pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2013-11, Income Taxes (Topic 740)—Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) ("ASU 2013-11") to provide explicit guidance on the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. ASU 2013-11 is effective for fiscal years, and interim periods within those years, beginning after December 31, 2013. The Company intends to adopt this standard prospectively in the first quarter of 2014 and the adoption will not result in a change to the tax provision. The Company does not expect a significant impact to its presentation of long-term taxes payable or its deferred tax assets.
	In February 2013, the FASB issued ASU No. 2013-02, Comprehensive Income (Topic 220)—Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02"), which amends FASB Accounting Standards Codification ("ASC") 220, Comprehensive Income to include the reporting of reclassifications from accumulated other comprehensive income to the respective line items in net income. The Company adopted ASU 2013-02 during the first quarter of 2013 and presented the effects within the Condensed Consolidated Statements of Comprehensive Income and the accompanying notes.
	In December 2011, the FASB issued ASU No. 2011-11, Balance Sheet (Topic 210)—Disclosures About Offsetting Assets and Liabilities ("ASU 2011-11"), and in January 2013 issued ASU No. 2013-01, Balance Sheet (Topic 210)—Clarifying the Scope of Disclosures About Offsetting Assets and Liabilities ("ASU 2013-01"). These standards create new disclosure requirements regarding the nature of an entity's rights of setoff and related arrangements associated with its derivative instruments, repurchase agreements, and securities lending transactions. Disclosures of certain instruments subject to enforceable master netting arrangements would be required, irrespective of whether the entity has elected to offset those instruments in the statement of financial position. The Company adopted these standards in the first quarter of 2013 and presented the effects in the accompanying notes.

Cash_Equivalents_and_Investmen1

Cash Equivalents and Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Cash Equivalents and Investments [Abstract]	'
Unrealized gains and losses and fair value of available-for-sale and trading securities	'
	The following tables summarize the Company's unrealized gains and losses and fair value of investments designated as available-for-sale and trading securities as of September 30, 2013 and December 31, 2012 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of September 30, 2013
	Cash equivalents:
	Certificates of deposit	$	0.1	$	—		$	—		$	0.1
	Government-sponsored enterprise obligations	8.6		—			—			8.6
	Money market funds	956		—			—			956
	U.S. government securities	85		—			—			85
	Total cash equivalents	1,049.70		—			—			1,049.70
	Restricted investments:
	Money market funds	88.1		—			—			88.1
	Mutual funds	2.4		0.1			—			2.5
	Total restricted investments	90.5		0.1			—			90.6
	Fixed income securities:
	Asset-backed securities	253.8		0.1			(0.2		)	253.7
	Certificates of deposit	24.8		—			—			24.8
	Commercial paper	11.5		—			—			11.5
	Corporate debt securities	768.2		1.5			(0.6		)	769.1
	Foreign government debt securities	15.8		—			—			15.8
	Government-sponsored enterprise obligations	315.1		0.2			(0.2		)	315.1
	U.S. government securities	230.4		0.1			—			230.5
	Total fixed income securities	1,619.60		1.9			(1.0		)	1,620.50
	Publicly-traded equity securities	15.2		111.5			—			126.7
	Total available-for-sale securities	2,775.00		113.5			(1.0		)	2,887.50
	Trading securities in mutual funds(*)	15.1		—			—			15.1
	Total	$	2,790.10	$	113.5		$	(1.0	)	$	2,902.60
	Reported as:
	Cash equivalents	$	1,049.70	$	—		$	—		$	1,049.70
	Restricted investments	90.5		0.1			—			90.6
	Short-term investments	461.7		112			—			573.7
	Long-term investments	1,188.20		1.4			(1.0		)	1,188.60
	Total	$	2,790.10	$	113.5		$	(1.0	)	$	2,902.60
	________________________________
	(*)	Balance includes the Company's non-qualified deferred compensation plan assets.
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of December 31, 2012
	Cash equivalents:
	Certificates of deposit	$	0.6	$	—		$	—		$	0.6
	Commercial paper	10.8		—			—			10.8
	Government-sponsored enterprise obligations	6.1		—			—			6.1
	Money market funds	1,042.60		—			—			1,042.60
	U.S. government securities	165.8		—			—			165.8
	Total cash equivalents	1,225.90		—			—			1,225.90
	Restricted investments:
	Money market funds	102.6		—			—			102.6
	Mutual funds	2.9		0.1			—			3
	Total restricted investments	105.5		0.1			—			105.6
	Fixed income securities:
	Asset-backed securities	226.2		0.3			(0.1		)	226.4
	Certificates of deposit	41.9		—			—			41.9
	Commercial paper	11.6		—			—			11.6
	Corporate debt securities	533.4		2.3			(0.1		)	535.6
	Foreign government debt securities	5		—			—			5
	Government-sponsored enterprise obligations	264.6		0.3			—			264.9
	U.S. government securities	328.6		0.1			—			328.7
	Total fixed income securities	1,411.30		3			(0.2		)	1,414.10
	Publicly-traded equity securities	3		—			(0.1		)	2.9
	Total available-for-sale securities	2,745.70		3.1			(0.3		)	2,748.50
	Trading securities in mutual funds(*)	12.6		—			—			12.6
	Total	$	2,758.30	$	3.1		$	(0.3	)	$	2,761.10
	Reported as:
Cash equivalents	$	1,225.90	$	—		$	—		$	1,225.90
Restricted investments	105.5		0.1			—			105.6
Short-term investments	441.3		0.3			(0.1		)	441.5
Long-term investments	985.6		2.7			(0.2		)	988.1
Total	$	2,758.30	$	3.1		$	(0.3	)	$	2,761.10
________________________________
(*)	Balance includes the Company's non-qualified deferred compensation plan assets.
Maturities of fixed income securities	'
	The following table presents the maturities of the Company's total fixed income securities as of September 30, 2013 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	Due within one year	$	431.4	$	0.5		$	—		$	431.9
	Due between one and five years	1,188.20		1.4			(1.0		)	1,188.60
	Total	$	1,619.60	$	1.9		$	(1.0	)	$	1,620.50
Available-for-sale securities in unrealized loss position	'
	The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of September 30, 2013 and December 31, 2012 (in millions):
		Less than 12 Months					12 Months or Greater					Total
		Fair		Unrealized			Fair			Unrealized		Fair		Unrealized
		Value		Loss			Value			Loss		Value		Loss
	As of September 30, 2013
	Fixed income securities:
	Asset-backed securities	$	172.6	$	(0.2	)	$	—		$	—	$	172.6	$	(0.2	)
	Corporate debt securities	286.6		(0.6		)	—			—		286.6		(0.6		)
	Foreign government debt securities (*)	15		—			—			—		15		—
	Government-sponsored enterprise obligations	158.3		(0.2		)	—			—		158.3		(0.2		)
	U.S. government securities (*)	46		—			—			—		46		—
	Total fixed income securities	$	678.5	$	(1.0	)	$	—		$	—	$	678.5	$	(1.0	)
	________________________________
	(*)	Balances for less than twelve months include investments that were in an immaterial loss position as of September 30, 2013.
		Less than 12 Months					12 Months or Greater					Total
		Fair		Unrealized			Fair			Unrealized		Fair		Unrealized
		Value		Loss			Value			Loss		Value		Loss
	As of December 31, 2012
	Fixed income securities:
	Asset-backed securities(*)	$	55.1	$	(0.1	)	$	0.1		$	—	$	55.2	$	(0.1	)
	Certificates of deposit	0.3		—			—			—		0.3		—
	Commercial paper	10		—			—			—		10		—
	Corporate debt securities	116		(0.1		)	—			—		116		(0.1		)
	Government-sponsored enterprise obligations	30		—			—			—		30		—
	U.S. government securities	68.2		—			—			—		68.2		—
	Total fixed income securities	279.6		(0.2		)	0.1			—		279.7		(0.2		)
	Publicly-traded equity securities	2.9		(0.1		)	—			—		2.9		(0.1		)
	Total available-for sale securities	$	282.5	$	(0.3	)	$	0.1		$	—	$	282.6	$	(0.3	)
	________________________________
	(*) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2012.
Restricted cash and investments	'
	The following table summarizes the Company's cash and investments that are classified as restricted cash and investments in the Condensed Consolidated Balance Sheets (in millions):
		As of
		September 30,		December 31,
		2013		2012
	Restricted cash	$	1.9	$	0.8
	Restricted investments	90.6		105.6
	Total restricted cash and investments	$	92.5	$	106.4

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Assets measured at fair value on a recurring basis	'
	The following tables provide a summary of assets and liabilities measured at fair value on a recurring basis and as reported in the Condensed Consolidated Balance Sheets (in millions):
		Fair Value Measurements at September 30, 2013 Using:
		Quoted Prices in		Significant Other			Significant Other
		Active Markets For		Observable			Unobservable
		Identical Assets		Remaining Inputs			Remaining Inputs
		(Level 1)		(Level 2)			(Level 3)		Total
	Assets measured at fair value:
	Available-for-sale securities:
	Asset-backed securities	$	—	$	253.7		$	—	$	253.7
	Certificates of deposit	—		24.9			—		24.9
	Commercial paper	—		11.5			—		11.5
	Corporate debt securities	—		769.1			—		769.1
	Foreign government debt securities	—		15.8			—		15.8
	Government-sponsored enterprise obligations	—		323.7			—		323.7
	Money market funds (1)	1,044.10		—			—		1,044.10
	Mutual funds (2)	2.5		—			—		2.5
	Publicly-traded equity securities	126.7		—			—		126.7
	U.S. government securities	182.2		133.3			—		315.5
	Total available-for-sale securities	1,355.50		1,532.00			—		2,887.50
	Trading securities in mutual funds (3)	15.1		—			—		15.1
	Derivative assets:
	Foreign exchange contracts	—		2.8			—		2.8
	Total assets measured at fair value	$	1,370.60	$	1,534.80		$	—	$	2,905.40
	Liabilities measured at fair value:
	Derivative liabilities:
	Foreign exchange contracts	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total liabilities measured at fair value	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total assets measured at fair value, reported as:
	Cash equivalents	$	961	$	88.7		$	—	$	1,049.70
	Restricted investments	90.6		—			—		90.6
	Short-term investments	259.1		314.6			—		573.7
	Long-term investments	59.9		1,128.70			—		1,188.60
	Prepaid expenses and other current assets	—		2.8			—		2.8
	Total assets measured at fair value	$	1,370.60	$	1,534.80		$	—	$	2,905.40
	Total liabilities measured at fair value, reported as:
	Other accrued liabilities	$	—	$	(3.4	)	$	—	$	(3.4	)
	Total liabilities measured at fair value	$	—	$	(3.4	)	$	—	$	(3.4	)
	________________________________
	(1)	Balance includes $88.1 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
	(2)	Balance relates to the restricted investments measured at fair market value of the Company's India Gratuity Trust.
	(3)	Balance relates to investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.
		Fair Value Measurements at December 31, 2012 Using:
		Quoted Prices in		Significant Other			Significant Other
		Active Markets For		Observable			Unobservable
		Identical Assets		Remaining Inputs			Remaining Inputs
		(Level 1)		(Level 2)			(Level 3)		Total
	Assets measured at fair value:
	Available-for-sale securities:
	Asset-backed securities	$	—	$	226.4		$	—	$	226.4
	Certificates of deposit	—		42.5			—		42.5
	Commercial paper	—		22.4			—		22.4
	Corporate debt securities	—		535.6			—		535.6
	Foreign government debt securities	—		5			—		5
	Government-sponsored enterprise obligations	254.9		16.1			—		271
	Money market funds (1)	1,145.20		—			—		1,145.20
	Mutual funds (2)	1		2			—		3
	Publicly-traded equity securities	2.9		—			—		2.9
	U.S. government securities	275.9		218.6			—		494.5
	Total available-for-sale securities	1,679.90		1,068.60			—		2,748.50
	Trading securities in mutual funds (3)	12.6		—			—		12.6
	Derivative assets:
	Foreign exchange contracts	—		3.5			—		3.5
	Total assets measured at fair value	$	1,692.50	$	1,072.10		$	—	$	2,764.60
Liabilities measured at fair value:
Derivative liabilities:
Foreign exchange contracts	$	—	$	0.1		$	—	$	0.1
Total liabilities measured at fair value	$	—	$	0.1		$	—	$	0.1
Total assets measured at fair value, reported as:
Cash equivalents	$	1,048.70	$	177.2		$	—	$	1,225.90
Restricted investments	103.6		2			—		105.6
Short-term investments	224.4		217.1			—		441.5
Long-term investments	315.8		672.3			—		988.1
Prepaid expenses and other current assets	—		3.5			—		3.5
Total assets measured at fair value	$	1,692.50	$	1,072.10		$	—	$	2,764.60
Total liabilities measured at fair value, reported as:
Other accrued liabilities	$	—	$	0.1		$	—	$	0.1
Total liabilities measured at fair value	$	—	$	0.1		$	—	$	0.1
________________________________
(1)	Balance includes $102.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
(2)	Balance relates to the restricted investments measured at fair market value of the Company's India Gratuity Trust.
(3)	Balance relates to investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.

Derivative_Instruments_Tables

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative instruments	'
	The notional amount of the Company's foreign currency derivatives are summarized as follows (in millions):
		As of
		September 30,		December 31,
		2013		2012
	Cash flow hedges	$	127.2	$	85.8
	Non-designated derivatives	153.5		112.8
	Total	$	280.7	$	198.6

Goodwill_and_Purchased_Intangi1

Goodwill and Purchased Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill	'
	The following table presents the goodwill activity allocated to the Company's reportable segments during the nine months ended September 30, 2013 (in millions):
		PSD			SSD			Total
	Balance as of December 31, 2012	$	1,866.30		$	2,191.50		$	4,057.80
	Reclassifications	(249.6		)	249.6			—
	Foreign currency translation adjustment	(0.1		)	—			(0.1		)
	Balance as of September 30, 2013	$	1,616.60		$	2,441.10		$	4,057.70
Finite lived and indefinite lived intangible assets by major class	'
	The Company’s purchased intangible assets were as follows (in millions):
		Gross			Accumulated			Impairments and			Net
					Amortization			Other Charges
	As of September 30, 2013
	Intangible assets with finite lives:
	Technologies and patents	$	581.4		$	(445.2	)	$	(30.5	)	$	105.7
	Customer contracts, support agreements, and	74.3			(61.9		)	(2.2		)	10.2
	related relationships
	Other	18.8			(18.8		)	—			—
	Total purchased intangible assets	$	674.5		$	(525.9	)	$	(32.7	)	$	115.9
	As of December 31, 2012
	Intangible assets with finite lives:
	Technologies and patents	$	554.1		$	(425.0	)	$	(30.5	)	$	98.6
	Customer contracts, support agreements, and	74.3			(59.2		)	(2.2		)	12.9
	related relationships
	Other	18.8			(18.8		)	—			—
	Total intangible assets with finite lives	647.2			(503.0		)	(32.7		)	111.5
	IPR&D with indefinite lives	17.4			—			—			17.4
	Total purchased intangible assets	$	664.6		$	(503.0	)	$	(32.7	)	$	128.9
Estimated future amortization expense of purchased intangible assets with definite lives	'
	As of September 30, 2013, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):
	Years Ending December 31,	Amount
	Remainder of 2013	$	9.1
	2014	36.2
	2015	32.6
	2016	18.5
	2017	10.5
	Thereafter	9
	Total	$	115.9

Other_Financial_Information_Ta

Other Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
Other Financial Information [Abstract]	'
Inventories, net	'
	Inventories, net, are reported within prepaid expenses and other current assets on the Condensed Consolidated Balance Sheets and consisted of the following (in millions):
		As of
		September 30,			December 31,
		2013			2012
	Inventories, net:
	Production materials	$	54.4		$	54.6
	Finished goods	0.8			4.1
	Total inventories, net	$	55.2		$	58.7
Warranties	'
	Changes in the Company’s warranty reserve during the nine months ended September 30, 2013 were as follows (in millions):
	Balance as of December 31, 2012	$	29.7
	Provisions made during the period, net	20.9
	Adjustments related to pre-existing warranties	(0.7		)
	Actual costs incurred during the period	(21.3		)
	Balance as of September 30, 2013	$	28.6
Deferred revenue	'
	Details of the Company's deferred revenue, as reported on the Condensed Consolidated Balance Sheets, were as follows (in millions):
		As of
		September 30,			December 31,
		2013			2012
	Deferred product revenue:
	Undelivered product commitments and other product deferrals	$	212.2		$	256.9
	Distributor inventory and other sell-through items	133.9			138.4
	Deferred gross product revenue	346.1			395.3
	Deferred cost of product revenue	(66.3		)	(99.4		)
	Deferred product revenue, net	279.8			295.9
	Deferred service revenue	741.4			627.5
	Total	$	1,021.20		$	923.4
	Reported as:
	Current	$	731.9		$	693.5
	Long-term	289.3			229.9
	Total	$	1,021.20		$	923.4
Other (expense) income, net	'
	Other expense, net, consisted of the following (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Interest income	$	2.3		$	2.6		$	6.1		$	8.3
	Interest expense	(14.2		)	(12.8		)	(43.4		)	(40.6		)
	Other	4.4			6.2			7.1			6.7
	Other expense, net	$	(7.5	)	$	(4.0	)	$	(30.2	)	$	(25.6	)

Restructuring_and_Other_Charge1

Restructuring and Other Charges (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring Charges [Abstract]	'
Summary of restructuring and other charges	'
	The following table presents restructuring and other charges included in cost of revenues and restructuring and other charges in the Condensed Consolidated Statements of Operations under the Company's restructuring plans (in millions):
		Three Months Ended September 30,					Nine Months Ended September 30,
		2013			2012		2013			2012
	Severance	$	3.8		$	29.1	$	9		$	33.4
	Facilities	(0.8		)	1.5		9.5			3.2
	Contract terminations and other	9.1			52.8		10.1			52
	Total	$	12.1		$	83.4	$	28.6		$	88.6
	Reported as:
	Cost of revenues	$	6.1		$	52.4	$	7.6		$	52.4
	Restructuring and other charges	6			31		21			36.2
	Total	$	12.1		$	83.4	$	28.6		$	88.6
Changes in restructuring liability	'
	The following table provides a summary of changes in the restructuring liability related to the Company's plans during the nine months ended September 30, 2013 (in millions):
		December 31,			Charges		Cash			Non-cash			September 30,
		2012					Payments			Settlements and			2013
										Other
	Severance	$	10.6		$	9	$	(14.8	)	$	(0.1	)	$	4.7
	Facilities	5.2			9.5		(4.4		)	(4.1		)	6.2
	Contract terminations and other	2.4			10.1		(5.5		)	(0.6		)	6.4
	Total	$	18.2		$	28.6	$	(24.7	)	$	(4.8	)	$	17.3

LongTerm_Debt_and_Financing_Ta

Long-Term Debt and Financing (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Instruments [Abstract]	'
Long-term debt	'
	The following table summarizes the Company's long-term debt (in millions, except percentages):
		As of September 30, 2013
		Amount			Effective Interest
					Rates
	Senior notes:
	3.10% fixed-rate notes, due 2016 ("2016 Notes")	$	300		3.12	%
	4.60% fixed-rate notes, due 2021 ("2021 Notes")	300			4.63	%
	5.95% fixed-rate notes, due 2041 ("2041 Notes")	400			6.01	%
	Total senior notes	1,000.00
	Unaccreted discount	(0.7		)
	Total	$	999.3

Equity_Tables

Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Stockholders' Equity Note [Abstract]	'
Accumulated other comprehensive (loss) income, net of tax	'
	The components of accumulated other comprehensive income, net of related taxes, during the nine months ended September 30, 2013 were as follows (in millions):
		Unrealized			Unrealized			Foreign			Total
		Gains (Losses)			Gains (Losses)			Currency
		on Available-for-			on Cash Flow			Translation
		Sale Securities(1)			Hedges(2)			Adjustments
	Balance as of December 31, 2012	$	2.1		$	3		$	(0.4	)	$	4.7
	Other comprehensive gain (loss) before reclassifications	70.8			(1.8		)	(5.4		)	63.6
	Amount reclassified from accumulated other	(0.8		)	(0.9		)	—			(1.7		)
	comprehensive income
	Other comprehensive gain (loss)	70			(2.7		)	(5.4		)	61.9
	Balance as of September 30, 2013	$	72.1		$	0.3		$	(5.8	)	$	66.6
	________________________________
	(1)	The reclassifications out of accumulated comprehensive income during the nine months ended September 30, 2013 for realized gains on available-for-sale securities of $0.8 million are included in other expense, net, in the Condensed Consolidated Statements of Operations.
	(2)	The reclassifications out of accumulated comprehensive income during the nine months ended September 30, 2013 for realized gains on cash flow hedges are included within cost of revenues of $0.5 million and sales and marketing of $1.3 million and for realized losses of $0.9 million within research and development for which the hedged transactions relate in the Condensed Consolidated Statements of Operations.
Other comprehensive income, tax	'
	The following table presents the taxes related to each component of other comprehensive income (in millions):
		Three Months Ended September 30, 2013									Nine Months Ended September 30, 2013
		Gross			Income Tax			Net			Gross			Income Tax			Net
		Amount			(Provision)			Amount			Amount			(Provision)			Amount
					Benefit									Benefit
	Available-for-sale securities:
	Change in unrealized gains (losses) on	$	101.6		$	(36.4	)	$	65.2		$	111.2		$	(40.4	)	$	70.8
	available-for-sale securities
	Reclassification adjustment for realized net	(0.4		)	0.1			(0.3		)	(1.1		)	0.3			(0.8		)
	gains on available-for-sale securities
	included in net income
	Net change in unrealized gains (losses)	101.2			(36.3		)	64.9			110.1			(40.1		)	70
	on available-for-sale securities
	Cash flow hedges:
	Change in unrealized (losses) gains on cash	(0.4		)	1.1			0.7			(4.2		)	2.4			(1.8		)
	flow hedges
	Reclassification adjustment for realized net	1.4			(0.8		)	0.6			(0.6		)	(0.3		)	(0.9		)
	losses (gains) on cash flow hedges
	included in net income
	Net change in unrealized gains (losses)	1			0.3			1.3			(4.8		)	2.1			(2.7		)
	on cash flow hedges
	Change in foreign currency adjustments	4.1			—			4.1			(5.4		)	—			(5.4		)
	Other comprehensive income	$	106.3		$	(36.0	)	$	70.3		$	99.9		$	(38.0	)	$	61.9

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of share-based compensation, stock options, activity	'
	The following table summarizes the Company’s stock option activity and related information as of and for the nine months ended September 30, 2013 (in millions, except for per share amounts and years):
		Outstanding Options
		Number of Shares			Weighted Average				Weighted Average		Aggregate
					Exercise Price				Remaining		Intrinsic
					per Share				Contractual Term		Value
									(In Years)
	Balance as of December 31, 2012	34.1			$	24.13
	Options granted	—			—
	Options canceled	(0.9	)		31.63
	Options exercised	(4.4	)		15.44
	Options expired	(3.1	)		28.28
	Balance as of September 30, 2013	25.7			$	24.87			2.7		$	34.3
	As of September 30, 2013:
	Vested and expected-to-vest options	25.2			$	24.95			2.6		$	31.7
	Exercisable options	22.1			$	25.07			2.2		$	19.8
Schedule of nonvested share activity	'
	The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the nine months ended September 30, 2013 (in millions, except per share amounts and years):
		Outstanding RSUs, RSAs, and PSAs
		Number of Shares			Weighted Average				Weighted Average		Aggregate
					Grant-Date Fair				Remaining		Intrinsic
					Value per Share				Contractual Term		Value
									(In Years)
	Balance as of December 31, 2012	26.8			$	27.76
	RSUs granted	9.7			20.29
	PSAs granted (*)	2.2			21.27
	RSUs vested	(4.6	)		27.74
	PSAs vested	(1.1	)		28.27
	RSAs vested	(1.1	)		19.59
	RSUs canceled	(2.5	)		23.14
	PSAs canceled	(2.8	)		29.94
	Balance as of September 30, 2013	26.6			$	25.05			1.3		$	529
	As of September 30, 2013:
	Vested and expected-to-vest RSUs, RSAs,	22.8			$	23.57			1.1		$	453.7
	and PSAs
	________________________________
	(*)	The number of shares subject to PSAs granted represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The aggregate number of shares subject to these PSAs that would be issued if performance goals determined by the Compensation Committee are achieved at target is 1.1 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 2.2 million shares.
Estimates of weighted average fair value per share under employee purchase plan and stock option plan	'
	The weighted-average assumptions used and the resulting estimates of fair value for stock options and ESPP were as follows:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Stock Options:
	Volatility	—		46%		—		46%
	Risk-free interest rate	—		0.70%		—		0.80%
	Expected life (years)	—		4.2		—		4.2
	Dividend yield	—		—		—		—
	Weighted-average fair value per share	—		$6.89		—		$8.46
	ESPP:
	Volatility	35%		42%		36%		47%
	Risk-free interest rate	0.10%		0.10%		0.10%		0.10%
	Expected life (years)	0.5		0.5		0.5		0.5
	Dividend yield	—		—		—		—
	Weighted-average fair value per share	$5.47		$4.77		$5.54		$5.53
Schedule of employee service share-based compensation, allocation of recognized period costs	'
	Share-based compensation expense associated with stock options, ESPP, RSUs, RSAs, and PSAs was recorded in the following cost and expense categories in the Company's Condensed Consolidated Statements of Operations (in millions):
		Three Months Ended September 30,								Nine Months Ended September 30,
		2013				2012				2013			2012
	Cost of revenues - Product	$	1.4			$	1.2			$	3.5		$	3.3
	Cost of revenues - Service	3.4				3.8				11.5			13.3
	Research and development	36.6				26.1				93.2			80.4
	Sales and marketing	20.4				21.4				53			64.3
	General and administrative	7.5				6.6				19.5			24.7
	Total	$	69.3			$	59.1			$	180.7		$	186
Disclosure of share-based compensation arrangements by share-based payment award	'
	The following table summarizes share-based compensation expense by award type (in millions):
		Three Months Ended September 30,								Nine Months Ended September 30,
		2013				2012				2013			2012
	Stock options	$	7.7			$	14.3			$	24.9		$	47.1
	RSUs, RSAs, and PSAs	57.7				40.1				144			123.3
	ESPP	3.9				4.7				11.8			15.6
	Total	$	69.3			$	59.1			$	180.7		$	186
Schedule of unrecognized compensation cost, nonvested awards	'
	The following table presents unrecognized compensation cost, adjusted for estimated forfeitures, recognized over a weighted-average period related to unvested stock options, RSUs, RSAs, and PSAs as of September 30, 2013 (in millions, except years):
		Unrecognized				Weighted Average
		Compensation Cost				Period
						(In Years)
	Stock options	$	41.4			2
	RSUs, RSAs, and PSAs	$	326.1			2

Segments_Tables

Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Financial information for each segment	'
	The following table summarizes financial information for each segment used by the CODM (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Net revenues:
	PSD	$	939.3		$	828.5		$	2,664.50		$	2,404.40
	SSD	246.3			289.8			731			820.2
	Total net revenues	$	1,185.60		$	1,118.30		$	3,395.50		$	3,224.60
	Segment contribution margin:
	PSD	$	424.1		$	318.9		$	1,151.70		$	910.9
	SSD	95.2			137			289.8			357.2
	Total segment contribution margin	$	519.3		$	455.9		$	1,441.50		$	1,268.10
	Corporate unallocated expenses(1)	$	(284.9	)	$	(266.5	)	$	(823.9	)	$	(794.2	)
	Amortization of purchased intangible assets(2)	(7.6		)	(9.0		)	(22.8		)	(25.1		)
	Share-based compensation expense	(69.3		)	(59.1		)	(180.7		)	(186.0		)
	Share-based payroll tax expense	(0.4		)	(0.1		)	(4.5		)	(1.0		)
	Restructuring and other charges(3)	(12.1		)	(83.4		)	(28.6		)	(88.6		)
	Acquisition and litigation charges	—			(0.3		)	(10.5		)	(1.3		)
	Other unallocated expense	—			5.3			—			5.3
	Total operating income	145			42.8			370.5			177.2
	Other expense, net	(7.5		)	(4.0		)	(30.2		)	(25.6		)
	Income before income taxes	$	137.5		$	38.8		$	340.3		$	151.6
	________________________________
	(1)	Amount includes unallocated costs for global functions such as sales, marketing, and general and administrative.
	(2)	Amount includes amortization expense of purchased intangible assets reported in cost of revenues and operating expenses.
	(3)	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.
Net revenues by geographic region	'
	The Company attributes revenues to geographic region based on the customer’s ship-to location. The following table presents net revenues by geographic region (in millions):
		Three Months Ended September 30,						Nine Months Ended September 30,
		2013			2012			2013			2012
	Americas:
	United States	$	604.6		$	507.6		$	1,761.80		$	1,513.60
	Other	56.7			52.7			166.7			165.3
	Total Americas	661.3			560.3			1,928.50			1,678.90
	Europe, Middle East, and Africa	306.5			321.3			898			927.7
	Asia Pacific	217.8			236.7			569			618
	Total	$	1,185.60		$	1,118.30		$	3,395.50		$	3,224.60

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Schedule of effective income tax rate reconciliation	'
	The effective tax rate for the three and nine months ended September 30, 2013 includes the effect of the following discrete items (in millions):
		Three Months Ended			Nine Months Ended
		30-Sep-13			30-Sep-13
	Section 199 deduction	$	(0.6	)	$	19.7
	Tax settlement with Internal Revenue Service (“IRS”)	$	—		$	27.8
	Reinstatement of the U.S. federal R&D tax credit	$	1		$	16.2

Net_Income_per_Share_Tables

Net Income per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of earnings per share, basic and diluted	'
	The Company computed basic and diluted net income per share as follows (in millions, except per share amounts):
		Three Months Ended September 30,				Nine Months Ended September 30,
		2013		2012		2013		2012
	Numerator:
	Net income	$	99.1	$	16.8	$	288	$	90.8
	Denominator:
	Weighted-average shares used to compute	501.5		521.2		503		525.4
	basic net income per share
	Dilutive effect of employee stock awards	7.1		3.3		7.7		4.9
	Weighted-average shares used to compute	508.6		524.5		510.7		530.3
	diluted net income per share
	Net income per share:
	Basic	$	0.2	$	0.03	$	0.57	$	0.17
	Diluted	$	0.19	$	0.03	$	0.56	$	0.17

Basis_of_Presentation_Details

Basis of Presentation (Details)	Jul. 31, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Company's interest in the joint venture - NSN	60.00%

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Details) (Depreciable Assets [Member], USD $)	3 Months Ended	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Depreciable Assets [Member]	'	'
Change in Accounting Estimate [Line Items]	'	'
Change in accounting estimate, depreciation expense impact	($9.40)	($20.40)
Change in accounting estimate, diluted net income per share impact	$0.01	$0.03

Business_Combinations_Details

Business Combinations (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Business Combinations [Abstract]	'	'	'	'
Business combination consideration	'	'	$10	'
Net tangible assets/(liabilities) acquired	0.1	'	0.1	'
Acquired finite lived intangible assets, amount	9.9	'	9.9	'
Business combination, acquisition related costs	$0	$0.30	$0.20	$1.30

Cash_Equivalents_and_Investmen2

Cash Equivalents and Investments - Available-For-Sale and Trading Securities (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	$2,775		$2,745.70
Available-for-sale securities, gross unrealized gains	113.5		3.1
Available-for-sale securities, gross unrealized losses	-1		-0.3
Available-for-sale securities, estimated fair value	2,887.50		2,748.50
Trading securities:	'		'
Trading securities, amortized cost	15.1	[1]	12.6	[1]
Trading securities, gross unrealized gains	0	[1]	0	[1]
Trading securities, gross unrealized losses	0	[1]	0	[1]
Trading securities, estimated fair value	15.1	[1]	12.6	[1]
Available-for-sale and Trading Securities [Abstract]	'		'
Total investments, amortized cost	2,790.10		2,758.30
Total investments, gross unrealized gains	113.5		3.1
Total investments, gross unrealized losses	-1		-0.3
Total investments, estimated fair value	2,902.60		2,761.10
Cash equivalents [Member]	'		'
Available-for-sale and Trading Securities [Abstract]	'		'
Total investments, amortized cost	1,049.70		1,225.90
Total investments, gross unrealized gains	0		0
Total investments, gross unrealized losses	0		0
Total investments, estimated fair value	1,049.70		1,225.90
Restricted investments [Member]	'		'
Available-for-sale and Trading Securities [Abstract]	'		'
Total investments, amortized cost	90.5		105.5
Total investments, gross unrealized gains	0.1		0.1
Total investments, gross unrealized losses	0		0
Total investments, estimated fair value	90.6		105.6
Short-term investments [Member]	'		'
Available-for-sale and Trading Securities [Abstract]	'		'
Total investments, amortized cost	461.7		441.3
Total investments, gross unrealized gains	112		0.3
Total investments, gross unrealized losses	0		-0.1
Total investments, estimated fair value	573.7		441.5
Long-term investments [Member]	'		'
Available-for-sale and Trading Securities [Abstract]	'		'
Total investments, amortized cost	1,188.20		985.6
Total investments, gross unrealized gains	1.4		2.7
Total investments, gross unrealized losses	-1		-0.2
Total investments, estimated fair value	1,188.60		988.1
Debt Securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	1,619.60		1,411.30
Available-for-sale securities, gross unrealized gains	1.9		3
Available-for-sale securities, gross unrealized losses	-1		-0.2
Available-for-sale securities, estimated fair value	1,620.50		1,414.10
Asset-backed securities	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	253.8		226.2
Available-for-sale securities, gross unrealized gains	0.1		0.3
Available-for-sale securities, gross unrealized losses	-0.2		-0.1
Available-for-sale securities, estimated fair value	253.7		226.4
Certificates of deposit [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	24.8		41.9
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	24.8		41.9
Commercial paper [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	11.5		11.6
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	11.5		11.6
Corporate debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	768.2		533.4
Available-for-sale securities, gross unrealized gains	1.5		2.3
Available-for-sale securities, gross unrealized losses	-0.6		-0.1
Available-for-sale securities, estimated fair value	769.1		535.6
Foreign government debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	15.8		5
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	15.8		5
Government-sponsored enterprise obligations [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	315.1		264.6
Available-for-sale securities, gross unrealized gains	0.2		0.3
Available-for-sale securities, gross unrealized losses	-0.2		0
Available-for-sale securities, estimated fair value	315.1		264.9
US government securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	230.4		328.6
Available-for-sale securities, gross unrealized gains	0.1		0.1
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	230.5		328.7
Publicly-traded equity securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	15.2		3
Available-for-sale securities, gross unrealized gains	111.5		0
Available-for-sale securities, gross unrealized losses	0		-0.1
Available-for-sale securities, estimated fair value	126.7		2.9
Money market funds [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	88.1		102.6
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	88.1		102.6
Mutual funds [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	2.4		2.9
Available-for-sale securities, gross unrealized gains	0.1		0.1
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	2.5		3
Restricted investments [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	90.5		105.5
Available-for-sale securities, gross unrealized gains	0.1		0.1
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	90.6		105.6
Certificates of deposit [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	0.1		0.6
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	0.1		0.6
Commercial paper [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	'		10.8
Available-for-sale securities, gross unrealized gains	'		0
Available-for-sale securities, gross unrealized losses	'		0
Available-for-sale securities, estimated fair value	'		10.8
Government-sponsored enterprise obligations [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	8.6		6.1
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	8.6		6.1
Money market funds [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	956		1,042.60
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	956		1,042.60
US government securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	85		165.8
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	85		165.8
Cash equivalents [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	1,049.70		1,225.90
Available-for-sale securities, gross unrealized gains	0		0
Available-for-sale securities, gross unrealized losses	0		0
Available-for-sale securities, estimated fair value	$1,049.70		$1,225.90
[1]	Balance includes the Company's non-qualified deferred compensation plan assets.

Cash_Equivalents_and_Investmen3

Cash Equivalents and Investments - Maturities of Fixed Income Investments (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Schedule of Fixed Income Securities Maturities [Abstract]	'
Amortized cost due within one year	$431.40
Gross unrealized gains due within one year	0.5
Gross unrealized losses due within one year	0
Estimated fair value due within one year	431.9
Amortized cost due between one and five years	1,188.20
Gross unrealized gains due between one and five years	1.4
Gross unrealized losses due between one and five year	-1
Estimated fair value due between one and five year	1,188.60
Total investments, amortized cost	1,619.60
Gross Unrealized Gains	1.9
Gross Unrealized Losses	-1
Total investments, estimated fair value	$1,620.50

Cash_Equivalents_and_Investmen4

Cash Equivalents and Investments - Unrealized Loss on Available-for-Sale Securities (Details) (USD $)	9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		$282.50
Unrealized loss, less than 12 months	'		-0.3
Fair value, 12 months or greater	'		0.1
Unrealized loss, 12 months or greater	'		0
Total fair value, available-for-sale investments in continuous unrealized loss position	'		282.6
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	'		-0.3
Debt Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	678.5		279.6
Unrealized loss, less than 12 months	-1		-0.2
Fair value, 12 months or greater	0		0.1
Unrealized loss, 12 months or greater	0		0
Total fair value, available-for-sale investments in continuous unrealized loss position	678.5		279.7
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	-1		-0.2
Asset-backed securities	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	172.6		55.1	[1]
Unrealized loss, less than 12 months	-0.2		-0.1	[1]
Fair value, 12 months or greater	0		0.1	[1]
Unrealized loss, 12 months or greater	0		0	[1]
Total fair value, available-for-sale investments in continuous unrealized loss position	172.6		55.2	[1]
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	-0.2		-0.1	[1]
Certificates of deposit [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		0.3
Unrealized loss, less than 12 months	'		0
Fair value, 12 months or greater	'		0
Unrealized loss, 12 months or greater	'		0
Total fair value, available-for-sale investments in continuous unrealized loss position	'		0.3
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	'		0
Commercial paper [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		10
Unrealized loss, less than 12 months	'		0
Fair value, 12 months or greater	'		0
Unrealized loss, 12 months or greater	'		0
Total fair value, available-for-sale investments in continuous unrealized loss position	'		10
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	'		0
Corporate debt securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	286.6		116
Unrealized loss, less than 12 months	-0.6		-0.1
Fair value, 12 months or greater	0		0
Unrealized loss, 12 months or greater	0		0
Total fair value, available-for-sale investments in continuous unrealized loss position	286.6		116
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	-0.6		-0.1
Foreign government debt securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	15	[2]	'
Unrealized loss, less than 12 months	0	[2]	'
Fair value, 12 months or greater	0	[2]	'
Unrealized loss, 12 months or greater	0	[2]	'
Total fair value, available-for-sale investments in continuous unrealized loss position	15	[2]	'
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	0	[2]	'
Government-sponsored enterprise obligations [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	158.3		30
Unrealized loss, less than 12 months	-0.2		0
Fair value, 12 months or greater	0		0
Unrealized loss, 12 months or greater	0		0
Total fair value, available-for-sale investments in continuous unrealized loss position	158.3		30
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	-0.2		0
US government securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	46	[2]	68.2
Unrealized loss, less than 12 months	0	[2]	0
Fair value, 12 months or greater	0	[2]	0
Unrealized loss, 12 months or greater	0	[2]	0
Total fair value, available-for-sale investments in continuous unrealized loss position	46	[2]	68.2
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	0	[2]	0
Publicly-traded equity securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		2.9
Unrealized loss, less than 12 months	'		-0.1
Fair value, 12 months or greater	'		0
Unrealized loss, 12 months or greater	'		0
Total fair value, available-for-sale investments in continuous unrealized loss position	'		2.9
Total unrealized loss, available-for-sale investments in continuous unrealized loss position	'		($0.10)
[1]	Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of DecemberB 31, 2012.
[2]	Balances for less than twelve months include investments that were in an immaterial loss position as of September 30, 2013.

Cash_Equivalents_and_Investmen5

Cash Equivalents and Investments - Restricted Cash and Investments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Restricted Cash and Investments [Abstract]	'	'
Restricted investments	$88.10	$102.60
Restricted cash and investments	92.5	106.4
Restricted cash [Member]	'	'
Restricted Cash and Investments [Abstract]	'	'
Restricted cash	1.9	0.8
Restricted investments [Member]	'	'
Restricted Cash and Investments [Abstract]	'	'
Restricted investments	$90.60	$105.60

Cash_Equivalents_and_Investmen6

Cash Equivalents, and Investments - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
	Investment		Investment		Investment
Cash Equivalents and Investments [Abstract]	'	'	'	'	'
Total investments in unrealized loss position	230	'	230	'	98
Privately-held investments	$36.50	'	$36.50	'	$32
Cost method investment, amount reclassified to short-term investments subsequent to investee initial public offering	7.6	'	'	'	'
Unrealized gain on cost method investments recorded upon investee initial public offering	100	'	100	'	'
Privately-held investments, other than temporary impairment	$2.10	$6	$2.50	$20	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Available-for-sale securities:	'		'
Available-for-sale securities	$2,887.50		$2,748.50
Trading securities:	'		'
Trading securities	15.1	[1]	12.6	[1]
Fair Value Measurements (Textuals)	'		'
Restricted investments	88.1		102.6
Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	2,905.40		2,764.60
Liabilities measured at fair value:	'		'
Other accrued liabilities	-3.4		0.1
Total liabilities measured at fair value	-3.4		0.1
Cash equivalents measured at fair value	1,049.70		1,225.90
Restricted investments measured at fair value	90.6		105.6
Short-term investments measured at fair value	573.7		441.5
Long-term investments measured at fair value	1,188.60		988.1
Prepaid expenses and other current assets measured at fair value	2.8		3.5
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	1,370.60		1,692.50
Liabilities measured at fair value:	'		'
Other accrued liabilities	0		0
Total liabilities measured at fair value	0		0
Cash equivalents measured at fair value	961		1,048.70
Restricted investments measured at fair value	90.6		103.6
Short-term investments measured at fair value	259.1		224.4
Long-term investments measured at fair value	59.9		315.8
Prepaid expenses and other current assets measured at fair value	0		0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	1,534.80		1,072.10
Liabilities measured at fair value:	'		'
Other accrued liabilities	-3.4		0.1
Total liabilities measured at fair value	-3.4		0.1
Cash equivalents measured at fair value	88.7		177.2
Restricted investments measured at fair value	0		2
Short-term investments measured at fair value	314.6		217.1
Long-term investments measured at fair value	1,128.70		672.3
Prepaid expenses and other current assets measured at fair value	2.8		3.5
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	0		0
Liabilities measured at fair value:	'		'
Other accrued liabilities	0		0
Total liabilities measured at fair value	0		0
Cash equivalents measured at fair value	0		0
Restricted investments measured at fair value	0		0
Short-term investments measured at fair value	0		0
Long-term investments measured at fair value	0		0
Prepaid expenses and other current assets measured at fair value	0		0
Foreign exchange contract [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets	2.8		3.5
Liabilities measured at fair value:	'		'
Derivative liabilities	-3.4		0.1
Foreign exchange contract [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets	0		0
Liabilities measured at fair value:	'		'
Derivative liabilities	0		0
Foreign exchange contract [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets	2.8		3.5
Liabilities measured at fair value:	'		'
Derivative liabilities	-3.4		0.1
Foreign exchange contract [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets	0		0
Liabilities measured at fair value:	'		'
Derivative liabilities	0		0
Asset-backed Securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	253.7		226.4
Asset-backed Securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	253.7		226.4
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	253.7		226.4
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Certificates of deposit [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	24.8		41.9
Certificates of deposit [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	24.9		42.5
Certificates of deposit [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Certificates of deposit [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	24.9		42.5
Certificates of deposit [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Commercial paper [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	11.5		11.6
Commercial paper [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	11.5		22.4
Commercial paper [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Commercial paper [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	11.5		22.4
Commercial paper [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Corporate debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	769.1		535.6
Corporate debt securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	769.1		535.6
Corporate debt securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Corporate debt securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	769.1		535.6
Corporate debt securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Foreign government debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	15.8		5
Foreign government debt securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	15.8		5
Foreign government debt securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Foreign government debt securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	15.8		5
Foreign government debt securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Government-sponsored enterprise obligations [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	315.1		264.9
Government-sponsored enterprise obligations [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	323.7		271
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		254.9
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	323.7		16.1
Government-sponsored enterprise obligations [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Money market funds [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	1,044.10	[2]	1,145.20	[3]
Money market funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	1,044.10	[2]	1,145.20	[3]
Money market funds [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0	[2]	0	[3]
Money market funds [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0	[2]	0	[3]
Mutual funds [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	2.5	[4]	3	[4]
Trading securities:	'		'
Trading securities	15.1	[5]	12.6	[5]
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	2.5	[4]	1	[4]
Trading securities:	'		'
Trading securities	15.1	[5]	12.6	[5]
Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0	[4]	2	[4]
Trading securities:	'		'
Trading securities	0	[5]	0	[5]
Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0	[4]	0	[4]
Trading securities:	'		'
Trading securities	0	[5]	0	[5]
Publicly-traded equity securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	126.7		2.9
Publicly-traded equity securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	126.7		2.9
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	126.7		2.9
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Publicly-traded equity securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
US government securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	230.5		328.7
US government securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	315.5		494.5
US government securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	182.2		275.9
US government securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	133.3		218.6
US government securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	0		0
Available-for-sale securities [Member] | Estimate of Fair Value Measurement [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	2,887.50		2,748.50
Available-for-sale securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	1,355.50		1,679.90
Available-for-sale securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	1,532		1,068.60
Available-for-sale securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities	$0		$0
[1]	Balance includes the Company's non-qualified deferred compensation plan assets.
[2]	Balance includes $88.1 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
[3]	Balance includes $102.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisition-related escrows.
[4]	Balance relates to the restricted investments measured at fair market value of the Company's India Gratuity Trust.
[5]	Balance relates to investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.

Fair_Value_Measurements_Narrat

Fair Value Measurements - Narrative (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Transfers Between Level 1 and Level 2 [Abstract]	'	'	'	'	'
Assets, level 1 to level 2 transfers, amount	$287,400,000	$0	$287,400,000	$0	'
Assets, level 2 to level 1 transfers, amount	0	0	0	0	'
Liabilities, level 1 to level 2 transfers, amount	0	0	0	0	'
Liabilities, level 2 to level 1 transfers, amount	0	0	0	0	'
Cost Method Investments	36,500,000	'	36,500,000	'	32,000,000
Fair value cost method investment subsequent to impairment	2,100,000	'	2,500,000	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0	0	0	'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3	0	0	0	0	'
Fair Value, Measurements, Nonrecurring [Member]	'	'	'	'	'
Fair Value, Transfers Between Level 1 and Level 2 [Abstract]	'	'	'	'	'
Cost Method Measured at Fair Value	4,300,000	'	4,700,000	'	'
Liabilities, Fair Value Disclosure	0	'	0	'	0
Assets, Fair Value Disclosure	$0	'	$0	'	$0

Derivative_Instruments_Details

Derivative Instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivatives	$280.70	$198.60
Designated as hedging instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivatives	127.2	85.8
Not designated as hedging instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivatives	$153.50	$112.80

Derivative_Instruments_Cash_Fl

Derivative Instruments, Cash Flow Hedges and Offsetting of Derivatives (Details) (USD $)

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Operating expense

Operating expense

Operating expense

Operating expense

Other current assets [Member]

Other current assets [Member]

Other current liabilities [Member]

Other current liabilities [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Foreign exchange contract [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Cash flow hedging [Member]

Derivatives, Fair Value [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum length of time hedged in cash flow hedge

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative asset designated as hedging instrument, Fair value

'

'

'

'

'

'

'

'

'

'

$2.80

$3.50

'

'

Derivative liability designated as hedging instrument, Fair value

'

'

'

'

'

'

'

'

'

'

'

'

3.4

0.1

Derivative instruments, loss recognized in other comprehensive income (loss), Effective portion

'

'

0.4

'

4.2

'

'

'

'

'

'

'

'

'

Derivative instruments, loss reclassified from accumulated OCI into income, Effective portion

'

'

'

'

'

'

1.4

3.2

'

8.7

'

'

'

'

Derivative instruments, gain reclassified from accumulated OCI into income, Effective portion

'

'

'

'

'

'

'

'

0.6

'

'

'

'

'

Derivative instruments, gain recognized in other comprehensive income (loss), Effective portion

'

'

'

5.7

'

6.5

'

'

'

'

'

'

'

'

Amount of derivative asset offset under a master netting arrangement

1.1

0.1

'

'

'

'

'

'

'

'

'

'

'

'

Amount of derivative liability offset under a master netting arrangement

1.1

0.1

'

'

'

'

'

'

'

'

'

'

'

'

Net derivative assets

1.7

3.4

'

'

'

'

'

'

'

'

'

'

'

'

Net derivative liabilities

$2.30

'

'

'

'

'

'

'

'

'

'

'

'

'

Derivative_Instruments_NonDesi

Derivative Instruments, Non-Designated Hedges (Details) (Foreign exchange contract [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Maturity period of non designated hedges derivatives	'	'	'2 months	'
Other income (expense), net [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative instruments not designated as hedging instruments, net gain	$0.90	$0.30	$1	$0.50

Goodwill_and_Purchased_Intangi2

Goodwill and Purchased Intangible Assets, Goodwill (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Goodwill [Roll Forward]	'
Balance as of December 31, 2012	$4,057.80
Reclassifications	0
Foreign currency translation adjustment	-0.1
Balance as of September 30, 2013	4,057.70
PSD segment	'
Goodwill [Roll Forward]	'
Balance as of December 31, 2012	1,866.30
Reclassifications	-249.6
Foreign currency translation adjustment	-0.1
Balance as of September 30, 2013	1,616.60
SSD segment	'
Goodwill [Roll Forward]	'
Balance as of December 31, 2012	2,191.50
Reclassifications	249.6
Foreign currency translation adjustment	0
Balance as of September 30, 2013	$2,441.10

Goodwill_and_Purchased_Intangi3

Goodwill and Purchased Intangible Assets, Purchased Intangible Assets (Details) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Finite-lived intangible assets, gross	'		'		'		'		$647,200,000
Finite-lived intangible assets, accumulated amortization	'		'		'		'		-503,000,000
Finite-lived intangible assets, impairments and other charges	'		'		'		'		-32,700,000
Finite-lived intangible assets, net	115,900,000		'		115,900,000		'		111,500,000
Total purchased intangible assets, gross	674,500,000		'		674,500,000		'		664,600,000
Total purchased intangible assets, accumulated amortization	-525,900,000		'		-525,900,000		'		-503,000,000
Total purchased intangible assets, impairments and other charges	-32,700,000		'		-32,700,000		'		-32,700,000
Total purchased intangible assets, net	115,900,000		'		115,900,000		'		128,900,000
Reclassifications	'		'		0		'		'
Amortization of purchased intangible assets	7,600,000	[1]	9,000,000	[1]	22,800,000	[1]	25,100,000	[1]	'
Carrying value of intangible assets	'		5,400,000		'		5,400,000		'
Fair value of intangible asset subsequent to impairment	'		0		'		0		'
Finite-lived intangible assets, impairment loss	0		16,100,000		0		16,100,000		'
Intangible assets no longer utilized	'		10,700,000		'		10,700,000		'
In process research and development [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Finite-lived intangible assets, accumulated amortization	'		'		'		'		'
Indefinite-Lived Intangible Assets (Excluding Goodwill)	'		'		'		'		17,400,000
Indefinite Lived Intangible Assets (Excluding Goodwill) Reclassified As Finite Lived Intangible Assets	17,400,000		'		17,400,000		'		'
Indefinite-lived intangible assets, impairments and other charges	'		'		'		'		0
Technologies and patents [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Finite-lived intangible assets, gross	581,400,000		'		581,400,000		'		554,100,000
Finite-lived intangible assets, accumulated amortization	-445,200,000		'		-445,200,000		'		-425,000,000
Finite-lived intangible assets, impairments and other charges	-30,500,000		'		-30,500,000		'		-30,500,000
Finite-lived intangible assets, net	105,700,000		'		105,700,000		'		98,600,000
Customer contracts, support agreements, and related relationships [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Finite-lived intangible assets, gross	74,300,000		'		74,300,000		'		74,300,000
Finite-lived intangible assets, accumulated amortization	-61,900,000		'		-61,900,000		'		-59,200,000
Finite-lived intangible assets, impairments and other charges	-2,200,000		'		-2,200,000		'		-2,200,000
Finite-lived intangible assets, net	10,200,000		'		10,200,000		'		12,900,000
Other intangible assets [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Finite-lived intangible assets, gross	18,800,000		'		18,800,000		'		18,800,000
Finite-lived intangible assets, accumulated amortization	-18,800,000		'		-18,800,000		'		-18,800,000
Finite-lived intangible assets, impairments and other charges	0		'		0		'		0
Finite-lived intangible assets, net	0		'		0		'		0
PSD segment	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Reclassifications	'		'		-249,600,000		'		'
PSD segment | Business acquisition acquired entity contrail [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Reclassifications	70,600,000		'		'		'		'
PSD segment | Security other [Member]	'		'		'		'		'
Purchased Intangible Assets [Line Items]	'		'		'		'		'
Reclassifications	'		'		$179,000,000		'		'
[1]	Amount includes amortization expense of purchased intangible assets reported in cost of revenues and operating expenses.

Goodwill_and_Purchased_Intangi4

Goodwill and Purchased Intangible Assets, Estimated Future Amortization Expense Intangible Assets (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'	'
Remainder of 2013	$9.10	'
2014	36.2	'
2015	32.6	'
2016	18.5	'
2017	10.5	'
Thereafter	9	'
Finite-lived intangible assets, net	$115.90	$111.50

Other_Financial_Information_In

Other Financial Information, Inventories, Net (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2012
In Millions, unless otherwise specified			Restructuring plan 2012	Restructuring plan 2012
Inventory [Line Items]	'	'	'	'
Production materials	$54.40	$54.60	'	'
Finished goods	0.8	4.1	'	'
Total inventories, net	55.2	58.7	'	'
Inventory write-down	'	'	$36.30	$36.30

Other_Financial_Information_Wa

Other Financial Information, Warranties (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]	'
Balance as of December 31, 2012	$29.70
Provisions made during the period, net	20.9
Adjustments related to pre-existing warranties	-0.7
Actual costs incurred during the period	-21.3
Balance as of September 30, 2013	$28.60

Other_Financial_Information_De

Other Financial Information, Deferred Revenue (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Deferred product revenue [Abstract]	'	'
Deferred revenue	$1,021.20	$923.40
Deferred Revenue Reported as [Abstract]	'	'
Deferred revenue, current	731.9	693.5
Deferred revenue, long-term	289.3	229.9
Sales Revenue, Product, Net [Member]	'	'
Deferred product revenue [Abstract]	'	'
Undelivered product commitments and other product deferrals	212.2	256.9
Distributor inventory and other sell-through items	133.9	138.4
Deferred gross product revenue	346.1	395.3
Deferred cost of product revenue	-66.3	-99.4
Deferred revenue	279.8	295.9
Sales Revenue, Service, Net [Member]	'	'
Deferred product revenue [Abstract]	'	'
Deferred revenue	$741.40	$627.50

Other_Financial_Information_Ot

Other Financial Information, Other Expense, Net (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Financial Information [Abstract]	'	'	'	'
Interest income	$2.30	$2.60	$6.10	$8.30
Interest expense	-14.2	-12.8	-43.4	-40.6
Other	4.4	6.2	7.1	6.7
Other expense, net	-7.5	-4	-30.2	-25.6
Privately-held investments, net gain	$3.60	$5.80	$4.90	$6.60

Restructuring_and_Other_Charge2

Restructuring and Other Charges (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Restructuring Reserve [Roll Forward]	'		'		'		'
31-Dec-12	'		'		$18.20		'
Charges	12.1	[1]	83.4	[1]	28.6	[1]	88.6	[1]
Cash Payments	'		'		-24.7		'
Non-cash Settlements and Other	'		'		-4.8		'
30-Sep-13	17.3		'		17.3		'
Aggregate future restructuring charges expected	'		'		11		'
Cost of revenues	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	6.1		52.4		7.6		52.4
Operating expense	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	6		31		21		36.2
Restructuring plan 2012	'		'		'		'
Restructuring Reserve [Line Items]	'		'		'		'
Restructuring and related cost, cost incurred to date	'		'		111		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	1		'		17.6		'
Restructuring plan 2012 | Cost of revenues	'		'		'		'
Restructuring Reserve [Line Items]	'		'		'		'
Restructuring and related cost, cost incurred to date	'		'		56.9		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Restructuring related asset impairment charges	'		'		'		52.4
Restructuring plan 2012 | Operating expense	'		'		'		'
Restructuring Reserve [Line Items]	'		'		'		'
Restructuring and related cost, cost incurred to date	'		'		54.1		'
Severance	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
31-Dec-12	'		'		10.6		'
Charges	3.8		29.1		9		33.4
Cash Payments	'		'		-14.8		'
Non-cash Settlements and Other	'		'		-0.1		'
30-Sep-13	4.7		'		4.7		'
Severance | Restructuring plan 2013	'		'		'		'
Restructuring Reserve [Line Items]	'		'		'		'
Restructuring and related cost, cost incurred to date	4.5		'		'		'
Severance | Restructuring plan 2012	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	'		29.1		'		29.1
Severance | Restructuring plan 2011	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	'		'		-0.1		'
Facilities	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
31-Dec-12	'		'		5.2		'
Charges	-0.8		1.5		9.5		3.2
Cash Payments	'		'		-4.4		'
Non-cash Settlements and Other	'		'		-4.1		'
30-Sep-13	6.2		'		6.2		'
Contract terminations and other	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
31-Dec-12	'		'		2.4		'
Charges	9.1		52.8		10.1		52
Cash Payments	'		'		-5.5		'
Non-cash Settlements and Other	'		'		-0.6		'
30-Sep-13	6.4		'		6.4		'
Contract terminations and other | Restructuring plan 2013	'		'		'		'
Restructuring Reserve [Line Items]	'		'		'		'
Restructuring and related cost, cost incurred to date	6.6		'		'		'
Contract terminations and other | Restructuring plan 2012	'		'		'		'
Restructuring Reserve [Roll Forward]	'		'		'		'
Charges	'		$0.40		'		$0.40
[1]	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.

LongTerm_Debt_and_Financing_De

Long-Term Debt and Financing (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Long-Term Debt [Line Items]	'	'	'	'	'
Long-term debt, gross	$1,000	'	$1,000	'	'
Unaccreted discount	-0.7	'	-0.7	'	'
Long-term debt	999.3	'	999.3	'	999.2
Long-term debt, Fair value	1,022.30	'	1,022.30	'	1,090.70
Financing Arrangements [Abstract]	'	'	'	'	'
Number of days due from receivable	'	'	'30 days	'	'
Sale of receivable	241.4	198.8	607.1	482	'
Proceeds from sale and collection of receivables	210.8	156.7	579.2	482.5	'
Receivables from sale of receivables	165.8	'	165.8	'	147.6
Cash received from financing provider that has not been recognized as revenue	72.5	'	72.5	'	30.7
Financing guarantee with recourse	'	'	'	'	'
Financing Arrangements [Abstract]	'	'	'	'	'
Guarantor obligations, current carrying value	32.2	'	32.2	'	'
Maximum	'	'	'	'	'
Financing Arrangements [Abstract]	'	'	'	'	'
Maximum term for guarantees related to third-party financing arrangements	'	'	'4 years	'	'
Fixed rate note due 2016	'	'	'	'	'
Long-Term Debt [Line Items]	'	'	'	'	'
Long-term debt, gross	300	'	300	'	'
Long-term debt, stated interest rate	3.10%	'	3.10%	'	'
Long-term debt, effective interest rate	3.12%	'	3.12%	'	'
Long-term debt, Maturity date	'	'	15-Mar-16	'	'
Fixed rate note due 2021	'	'	'	'	'
Long-Term Debt [Line Items]	'	'	'	'	'
Long-term debt, gross	300	'	300	'	'
Long-term debt, stated interest rate	4.60%	'	4.60%	'	'
Long-term debt, effective interest rate	4.63%	'	4.63%	'	'
Long-term debt, Maturity date	'	'	15-Mar-21	'	'
Fixed rate note due 2041	'	'	'	'	'
Long-Term Debt [Line Items]	'	'	'	'	'
Long-term debt, gross	$400	'	$400	'	'
Long-term debt, stated interest rate	5.95%	'	5.95%	'	'
Long-term debt, effective interest rate	6.01%	'	6.01%	'	'
Long-term debt, Maturity date	'	'	15-Mar-41	'	'

Equity_Stock_Repurchase_Activi

Equity, Stock Repurchase Activities (Details) (USD $)	1 Months Ended		3 Months Ended		9 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Jul. 31, 2013	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stockholders' Equity Note [Abstract]	'	'	'	'	'	'
Stock repurchase program, authorized amount	$1,000,000,000	$1,000,000,000	'	'	'	'
Stock repurchase program, remaining authorized repurchase amount	'	'	'	'	1,200,000,000	'
Stock repurchased and retired during period, shares	'	'	4.4	13.9	17	21.3
Common stock repurchased under stock repurchase program average purchase price	'	'	$20.92	$18	$19.32	$18.60
Common stock repurchased and retired under stock repurchase program, value	'	'	$92,900,000	$250,000,000	$328,400,000	$395,600,000

Equity_Accumulated_Other_Compr

Equity, Accumulated Other Comprehensive (Loss) Income, Net of Tax (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]	'		'	'		'
Accumulated other comprehensive (loss) income, beginning balance	'		'	$4.70		'
Other comprehensive gain (loss) before reclassifications	'		'	63.6		'
Amount reclassified from accumulated other comprehensive income	'		'	-1.7		'
Other comprehensive income, net of tax	70.3		13.6	61.9		22.9
Accumulated other comprehensive (loss) income, ending balance	66.6		'	66.6		'
Other expense, net	-7.5		-4	-30.2		-25.6
Cost of revenues	439.1		444.5	1,257.70		1,248.80
Research and development	264.6		288.2	784.5		826.5
Sales and marketing	268.7		261	790.1		778.2
Unrealized gains (losses) on available-for-sale securities	'		'	'		'
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]	'		'	'		'
Accumulated other comprehensive (loss) income, beginning balance	'		'	2.1	[1]	'
Other comprehensive gain (loss) before reclassifications	'		'	70.8	[1]	'
Amount reclassified from accumulated other comprehensive income	'		'	-0.8	[1]	'
Other comprehensive income, net of tax	'		'	70	[1]	'
Accumulated other comprehensive (loss) income, ending balance	72.1	[1]	'	72.1	[1]	'
Other expense, net	'		'	0.8		'
Unrealized gains (losses) on cash flow hedges	'		'	'		'
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]	'		'	'		'
Accumulated other comprehensive (loss) income, beginning balance	'		'	3	[2]	'
Other comprehensive gain (loss) before reclassifications	'		'	-1.8	[2]	'
Amount reclassified from accumulated other comprehensive income	'		'	-0.9	[2]	'
Other comprehensive income, net of tax	'		'	-2.7	[2]	'
Accumulated other comprehensive (loss) income, ending balance	0.3	[2]	'	0.3	[2]	'
Cost of revenues	'		'	0.5		'
Research and development	'		'	-0.9		'
Sales and marketing	'		'	1.3		'
Foreign currency translation adjustments	'		'	'		'
Accumulated Other Comprehensive (Loss) Income, Net of Tax [Roll Forward]	'		'	'		'
Accumulated other comprehensive (loss) income, beginning balance	'		'	-0.4		'
Other comprehensive gain (loss) before reclassifications	'		'	-5.4		'
Amount reclassified from accumulated other comprehensive income	'		'	0		'
Other comprehensive income, net of tax	'		'	-5.4		'
Accumulated other comprehensive (loss) income, ending balance	($5.80)		'	($5.80)		'
[1]	The reclassifications out of accumulated comprehensive income during the nine months ended SeptemberB 30, 2013 for realized gains on available-for-sale securities of $0.8 million are included in other expense, net, in the Condensed Consolidated Statements of Operations.
[2]	The reclassifications out of accumulated comprehensive income during the nine months ended SeptemberB 30, 2013 for realized gains on cash flow hedges are included within cost of revenues of $0.5 million and sales and marketing of $1.3 million and for realized losses of $0.9 million within research and development for which the hedged transactions relate in the Condensed Consolidated Statements of Operations.

Equity_Other_Comprehensive_Inc

Equity, Other Comprehensive Income (Loss), Gross Amount, Income Tax (Benefit) and Net Amount (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Available-for-sale securities:	'	'	'	'
Change in unrealized gains (losses) on available- for-sale securities, gross amount	$101.60	'	$111.20	'
Change in unrealized gains (losses) on available- for-sale securities, tax	-36.4	'	-40.4	'
Change in unrealized gains (losses) on available-for-sale securities, net of tax	65.2	2	70.8	4.1
Reclassification adjustment for realized net gains on available-for-sale securities included in net income, gross amount	-0.4	'	-1.1	'
Reclassification adjustment for realized net gains on available-for-sale securities included in net income, tax	0.1	'	0.3	'
Reclassification adjustment for realized net gains on available-for-sale securities included in net income	-0.3	-0.3	-0.8	-0.8
Other comprehensive income (loss), available-for-sale securities adjustment, gross amount	101.2	'	110.1	'
Other comprehensive income (loss), available-for-sale securities adjustment, tax	-36.3	'	-40.1	'
Net change in unrealized gains on available-for-sale securities	64.9	1.7	70	3.3
Cash flow hedges:	'	'	'	'
Change in unrealized (losses) gains on cash flow hedges, gross amount	-0.4	'	-4.2	'
Change in unrealized (losses) gains on cash flow hedges, tax	1.1	'	2.4	'
Change in unrealized (losses) gains on cash flow hedges, net of tax	0.7	4.3	-1.8	6.9
Reclassification adjustment for realized net losses (gains) on cash flow hedges included in net income, Gross amount	1.4	'	-0.6	'
Reclassification adjustment for realized net losses (gains) on cash flow hedges included in net income, tax	-0.8	'	-0.3	'
Reclassification adjustment for realized net losses (gains) on cash flow hedges included in net income	0.6	2.4	-0.9	7.4
Net change in unrealized gains (losses) on cash flow hedges, gross amount	1	'	-4.8	'
Net change in unrealized gains (losses) on cash flow hedges, Tax	0.3	'	2.1	'
Net change in unrealized gains (losses) on cash flow hedges	1.3	6.7	-2.7	14.3
Change in foreign currency translation adjustments, gross amount	4.1	'	-5.4	'
Change in foreign currency translation adjustments, Tax	0	'	0	'
Change in foreign currency translation adjustments	4.1	5.2	-5.4	5.3
Other comprehensive income (loss), gross amount	106.3	'	99.9	'
Other comprehensive income (loss), Tax	-36	'	-38	'
Other comprehensive income, net of tax	$70.30	$13.60	$61.90	$22.90

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
Share-Based Compensation Plans	'	'	'
Common stock, shares, issued	504,600,000	504,600,000	508,400,000
Outstanding stock options, restricted stock units, and restricted stock awards from awards assumed	5,500,000	5,500,000	'
Stock Option Activities [Roll Forward]	'	'	'
Beginning balance, number of shares	'	34,100,000	'
Options granted, number of shares	'	0	'
Options canceled, number of shares	'	-900,000	'
Options exercised, number of shares	'	-4,400,000	'
Options expired, number of shares	'	-3,100,000	'
Ending balance, number of shares	25,700,000	25,700,000	'
Weighted Average Exercise Price [Roll Forward]	'	'	'
Beginning balance, weighted average exercise price (in dollars per share)	'	$24.13	'
Options canceled, weighted average exercise price (in dollars per share)	'	$31.63	'
Options exercised, weighted average exercise price (in dollars per share)	'	$15.44	'
Options expired, weighted average exercise price (in dollars per share)	'	$28.28	'
Ending balance, weighted average exercise price (in dollars per share)	$24.87	$24.87	'
Weighted average remaining contractual term at period end	'	'2 years 8 months 12 days	'
Aggregate intrinsic value at period end	$34,300,000	$34,300,000	'
Vested or expected-to-vest options, number of shares at period end	25,200,000	25,200,000	'
Vested or expected-to-vest options, weighted average exercise price at period end (in dollars per share)	$24.95	$24.95	'
Vested and expected-to-vest options, weighted average remaining contractual term at period end	'	'2 years 7 months 6 days	'
Vested or expected-to-vest options, aggregate intrinsic value at period end	31,700,000	31,700,000	'
Exercisable options, number of shares at period end	22,100,000	22,100,000	'
Exercisable options, weighted average exercise price at period end (in dollars per share)	$25.07	$25.07	'
Exercisable options, weighted average remaining contractual term at period end	'	'2 years 2 months 12 days	'
Exercisable options, aggregate intrinsic value at period end	19,800,000	19,800,000	'
Share price (in dollars per share)	$19.86	$19.86	'
Pre-tax intrinsic value of options exercised	9,600,000	24,000,000	'
Equity incentive plan 2006	'	'	'
Share-Based Compensation Plans	'	'	'
Number of shares in authorized	149,500,000	149,500,000	'
Number of shares outstanding	46,800,000	46,800,000	'
Number of shares available for future issuance	47,400,000	47,400,000	'
Plan 1996 and 2000	'	'	'
Share-Based Compensation Plans	'	'	'
Maximum additional shares expire unexercised, under 1996 and 2000 plan	75,000,000	75,000,000	'
Employee stock purchase plan 2008	'	'	'
Share-Based Compensation Plans	'	'	'
Number of shares available for future issuance	6,200,000	6,200,000	'
Common stock, capital shares reserved for future issuance	19,000,000	19,000,000	'
Share-based compensation arrangement by share-based payment award, discount from market price	'	15.00%	'
Periodic payroll deduction - percentage of base salary	10.00%	10.00%	'
Maximum purchase of common stock, shares	'	6,000	'
Share-based compensation arrangement by share-based payment award, offering period	'	'12 months	'
Maximum purchase of common stock, value	'	$25,000	'
Share-based compensation arrangement by share-based payment award, expiration period	'	'1 year	'
Common stock, shares, issued	12,800,000	12,800,000	'

Employee_Benefit_Plans_Share_B

Employee Benefit Plans, Share Based Compensation, Equity Instruments Other Than Options (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Employee stock purchase plan 2008	'	'	'		'
Employee Stock Purchase Plan	'	'	'		'
Employee stock purchase plans offering period duration	'	'	'6 months		'
Stock issued during period, shares, employee stock purchase plans	1.5	1.9	3.3		3.6
Average price of common stock, per share	$18.42	$14.90	$16.53		$16.26
Restricted stock units (RSUs)	'	'	'		'
Restricted Stock Units, Restricted Stock Awards, and Performance Share Awards Activities [Roll Forward]	'	'	'		'
Awards granted, number of shares	'	'	9.7		'
Awards vested, number of shares	'	'	-4.6		'
Awards canceled, number of shares	'	'	-2.5		'
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'		'
Awards granted, weighted average grant-date fair value (in dollars per share)	'	'	$20.29		'
Awards vested, weighted average grant-date fair value (in dollars per share)	'	'	$27.74		'
Awards canceled, weighted average grant-date fair value (in dollars per share)	'	'	$23.14		'
Performance shares (PSAs)	'	'	'		'
Restricted Stock Units, Restricted Stock Awards, and Performance Share Awards Activities [Roll Forward]	'	'	'		'
Awards granted, number of shares	'	'	2.2	[1]	'
Awards vested, number of shares	'	'	-1.1		'
Awards canceled, number of shares	'	'	-2.8		'
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'		'
Awards granted, weighted average grant-date fair value (in dollars per share)	'	'	$21.27	[1]	'
Awards vested, weighted average grant-date fair value (in dollars per share)	'	'	$28.27		'
Awards canceled, weighted average grant-date fair value (in dollars per share)	'	'	$29.94		'
Aggregate number of shares subject to PSAs granted	'	'	1.1		'
Minimum shares to be issued on achievement of performance goals in respect of PSAs	'	'	0		'
Maximum shares to be issued on achievement of performance goals in respect of PSAs	'	'	2.2		'
Restricted stock awards (RSAs)	'	'	'		'
Restricted Stock Units, Restricted Stock Awards, and Performance Share Awards Activities [Roll Forward]	'	'	'		'
Awards vested, number of shares	'	'	-1.1		'
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'		'
Awards vested, weighted average grant-date fair value (in dollars per share)	'	'	$19.59		'
RSUs, RSAs, and PSAs	'	'	'		'
Restricted Stock Units, Restricted Stock Awards, and Performance Share Awards Activities [Roll Forward]	'	'	'		'
Beginning balance, number of shares	'	'	26.8		'
Ending balance, number of shares	26.6	'	26.6		'
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'	'	'		'
Beginning balance, weighted average grant-date fair value (in dollars per share)	'	'	$27.76		'
Ending balance, weighted average grant-date fair value (in dollars per share)	$25.05	'	$25.05		'
Weighted average remaining contractual terms	'	'	'1 year 3 months 18 days		'
RSUs and PSAs, aggregate intrinsic value at period end	$529	'	$529		'
Vested and expected-to-vest RSUs and PSAs, number of shares at period end	22.8	'	22.8		'
Vested and expected-to-vest RSUs and PSAs, weighted average grant-date fair value at period end (in dollars per share)	$23.57	'	$23.57		'
Vested and expected-to-vest RSUs and PSAs, weighted average remaining contractual term at period end	'	'	'1 year 1 month 6 days		'
Vested and expected-to-vest RSUs and PSAs, aggregate intrinsic value at period end	$453.70	'	$453.70		'
[1]	The number of shares subject to PSAs granted represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The aggregate number of shares subject to these PSAs that would be issued if performance goals determined by the Compensation Committee are achieved at target is 1.1 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 2.2 million shares.

Employee_Benefit_Plans_Assumpt

Employee Benefit Plans, Assumptions and Resulting Estimates of Fair Value (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock options	'	'	'	'
Estimates of Fair Value	'	'	'	'
Volatility	'	46.00%	'	46.00%
Risk-free interest rate	'	0.70%	'	0.80%
Expected life (years)	'	'4 years 2 months 12 days	'	'4 years 2 months 12 days
Dividend yield	'	0.00%	'	0.00%
Weighted-average fair value per share	'	$6.89	'	$8.46
Employee stock purchase plan	'	'	'	'
Estimates of Fair Value	'	'	'	'
Volatility	35.00%	42.00%	36.00%	47.00%
Risk-free interest rate	0.10%	0.10%	0.10%	0.10%
Expected life (years)	'6 months	'6 months	'6 months	'6 months
Dividend yield	0.00%	0.00%	0.00%	0.00%
Weighted-average fair value per share	$5.47	$4.77	$5.54	$5.53

Employee_Benefit_Plans_Share_B1

Employee Benefit Plans, Share Based Compensation by Cost and Expense Categories (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	$69.30	$59.10	$180.70	$186
Stock options	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	7.7	14.3	24.9	47.1
RSUs, RSAs, and PSAs	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	57.7	40.1	144	123.3
Employee stock purchase plan	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	3.9	4.7	11.8	15.6
Cost of revenues, product	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	1.4	1.2	3.5	3.3
Cost of revenues, service	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	3.4	3.8	11.5	13.3
Research and development expense	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	36.6	26.1	93.2	80.4
Selling and marketing expense	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	20.4	21.4	53	64.3
General and administrative expense	'	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'	'
Share-based compensation expense	$7.50	$6.60	$19.50	$24.70

Employee_Benefit_Plans_Share_B2

Employee Benefit Plans, Share Based Compensation by Share Based Payment Award Types (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Stock options	'
Unrecognized Compensation Cost [Abstract]	'
Unrecognized compensation cost related to unvested stock options - adjusted for forfeitures	$41.40
Weighted average period that unrecognized compensation cost will be recognized (years)	'2 years
RSUs, RSAs, and PSAs	'
Unrecognized Compensation Cost [Abstract]	'
Unrecognized compensation cost related to unvested stock options - adjusted for forfeitures	$326.10
Weighted average period that unrecognized compensation cost will be recognized (years)	'2 years

Segments_Details

Segments (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Net revenues:	'		'		'		'
Total net revenues	$1,185.60		$1,118.30		$3,395.50		$3,224.60
Segment contribution margin:	'		'		'		'
Total segment contribution margin	519.3		455.9		1,441.50		1,268.10
Corporate unallocated expenses	-284.9	[1]	-266.5	[1]	-823.9	[1]	-794.2	[1]
Amortization of purchased intangible assets	-7.6	[2]	-9	[2]	-22.8	[2]	-25.1	[2]
Share-based compensation expense	-69.3		-59.1		-180.7		-186
Share-based payroll tax expense	-0.4		-0.1		-4.5		-1
Restructuring and other charges	-12.1	[3]	-83.4	[3]	-28.6	[3]	-88.6	[3]
Acquisition and litigation charges	0		-0.3		-10.5		-1.3
Other unallocated expense	0		5.3		0		5.3
Operating income	145		42.8		370.5		177.2
Other expense, net	-7.5		-4		-30.2		-25.6
Income before income taxes	137.5		38.8		340.3		151.6
PSD segment	'		'		'		'
Net revenues:	'		'		'		'
Total net revenues	939.3		828.5		2,664.50		2,404.40
Segment contribution margin:	'		'		'		'
Total segment contribution margin	424.1		318.9		1,151.70		910.9
Depreciation by Segment [Abstract]	'		'		'		'
Depreciation expense	26.8		29.4		88.7		84.8
SSD segment	'		'		'		'
Net revenues:	'		'		'		'
Total net revenues	246.3		289.8		731		820.2
Segment contribution margin:	'		'		'		'
Total segment contribution margin	95.2		137		289.8		357.2
Depreciation by Segment [Abstract]	'		'		'		'
Depreciation expense	$7		$9.60		$23.60		$28
[1]	Amount includes unallocated costs for global functions such as sales, marketing, and general and administrative.
[2]	Amount includes amortization expense of purchased intangible assets reported in cost of revenues and operating expenses.
[3]	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.

Segments_Geographical_Details

Segments, Geographical (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	$1,185.60	$1,118.30	$3,395.50	$3,224.60
United states	'	'	'	'
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	604.6	507.6	1,761.80	1,513.60
Other americas	'	'	'	'
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	56.7	52.7	166.7	165.3
Americas	'	'	'	'
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	661.3	560.3	1,928.50	1,678.90
EMEA	'	'	'	'
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	306.5	321.3	898	927.7
Asia Pacific	'	'	'	'
Net Revenues by Geographic Region [Line Items]	'	'	'	'
Total net revenues	$217.80	$236.70	$569	$618

Segments_Major_Customers_Detai

Segments, Major Customers (Details)	3 Months Ended		9 Months Ended		12 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
	Sales revenue, segment	Sales revenue, segment	Sales revenue, segment	United states	United states	Verizon
	Customer concentration risk	Customer concentration risk	Customer concentration risk	Property, plant and equipment	Property, plant and equipment	Sales revenue, segment
	Customer	Customer	Customer	Geographic concentration risk	Geographic concentration risk	Customer concentration risk
Concentration Risk [Line Items]	'	'	'	'	'	'
Concentration risk, number of major customers	0	0	0	'	'	'
Concentration risk, percentage	'	'	'	84.00%	83.00%	10.20%

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2009	Sep. 30, 2013
					Foreign country	Maximum
Income Tax Contingency [Line Items]	'	'	'	'	'	'
Section 199 deduction	($0.60)	'	$19.70	'	'	'
Tax settlement with Internal Revenue Service (bIRSb)	0	'	27.8	'	'	'
Reinstatement of the U.S. federal R&D tax credit	1	'	16.2	'	'	'
Effective income tax rate reconciliation, at federal statutory income tax rate	35.00%	35.00%	35.00%	35.00%	'	'
Unrecognized tax benefits, period increase (decrease)	'	'	7.9	'	'	'
Unrecognized tax benefits	144	'	144	'	'	'
Unrecognized tax benefits that would impact effective tax rate	129.9	'	129.9	'	'	'
Greater than remote likelihood decrease in gross unrecognized tax benefits within next 12 months	'	'	'	'	'	3.4
Interest and penalties recorded	'	'	'	'	$4.60	'

Net_Income_per_Share_Details

Net Income per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Numerator	'	'	'	'
Net income	$99.10	$16.80	$288	$90.80
Denominator	'	'	'	'
Weighted-average shares used to compute basic net income per share	501.5	521.2	503	525.4
Dilutive effect of employee stock awards	7.1	3.3	7.7	4.9
Weighted-average shares used to compute diluted net income per share	508.6	524.5	510.7	530.3
Net income per share:	'	'	'	'
Basic (in dollars per share)	$0.20	$0.03	$0.57	$0.17
Diluted (in dollars per share)	$0.19	$0.03	$0.56	$0.17
Net Income per Share Textuals	'	'	'	'
Anti-dilutive shares excluded from computation of diluted earnings per share	21.8	36.8	22.3	33

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Summarization of principal contractual obligations	'	'	'	'	'
Future minimum payments under the non-cancelable operating leases	$229.30	'	$229.30	'	'
Rent expense	12.6	15.7	39.9	47.2	'
Total purchase commitments	553.3	'	553.3	'	'
Accrual for estimated carrying charges or obsolete materials charges	24.2	'	24.2	'	'
Long-term debt, carrying value	999.3	'	999.3	'	999.2
Long-term debt, gross	1,000	'	1,000	'	'
Indemnity-related and service-related escrows	92	'	92	'	'
Campus build out commitments	24	'	24	'	'
Other contractual obligations	16.1	'	16.1	'	'
Long-term income taxes payable	117.5	'	117.5	'	112.4
Fixed rate note due 2016	'	'	'	'	'
Summarization of principal contractual obligations	'	'	'	'	'
Long-term debt, gross	300	'	300	'	'
Long-term debt, interest rate, Stated percentage	3.10%	'	3.10%	'	'
Fixed rate note due 2021	'	'	'	'	'
Summarization of principal contractual obligations	'	'	'	'	'
Long-term debt, gross	300	'	300	'	'
Long-term debt, interest rate, Stated percentage	4.60%	'	4.60%	'	'
Fixed rate note due 2041	'	'	'	'	'
Summarization of principal contractual obligations	'	'	'	'	'
Long-term debt, gross	$400	'	$400	'	'
Long-term debt, interest rate, Stated percentage	5.95%	'	5.95%	'	'

Commitments_and_Contingencies_2

Commitments and Contingencies, Guarantees (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Guarantor Obligations [Line Items]	'	'
Campus build out commitments	$24	'
Financing guarantees, bank guarantees, and standby letters of credit	'	'
Guarantor Obligations [Line Items]	'	'
Guarantor obligations, current carrying value	42.4	12.6
Financing guarantee with recourse	'	'
Guarantor Obligations [Line Items]	'	'
Guarantor obligations, current carrying value	$32.20	'

Commitments_and_Contingencies_3

Commitments and Contingencies, Legal Proceedings (Details) (USD $)	Sep. 30, 2013	Sep. 09, 2011	Dec. 28, 2011
In Millions, unless otherwise specified		2011 California state derivative lawsuits	2011 Federal derivative lawsuit
		Lawsuit	Lawsuit
Loss Contingencies [Line Items]	'	'	'
Number of purported shareholder derivative actions	'	4	2
Settlement including interest with the IRS related to intercompany R&D cost sharing arrangement	$19.60	'	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended		9 Months Ended		1 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Nov. 08, 2013
					Subsequent event
Subsequent Event [Line Items]	'	'	'	'	'
Stock repurchased during period, shares	'	'	'	'	0.3
Stock repurchased during period, value	'	'	'	'	$7,000,000
Common stock repurchased under stock repurchase program average purchase price	$20.92	$18	$19.32	$18.60	$20.19
Stock repurchased and retired during period, shares	4.4	13.9	17	21.3	0.3
Stock repurchase program, remaining authorized repurchase amount	'	'	$1,200,000,000	'	$1,200,000,000