Juniper Networks (JNPR) 10-K 26 Feb 14 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 21, 2014	Jun. 28, 2013
Document and Entity Information [Abstract]	'	'	'
Entity Registrant Name	'JUNIPER NETWORKS INC	'	'
Entity Central Index Key	'0001043604	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
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	'	501,120,337	'
Entity Public Float	'	'	$6,490,000,000

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net revenues:	'	'	'
Product	$3,519.90	$3,262.10	$3,478.30
Service	1,149.20	1,103.30	970.4
Total net revenues	4,669.10	4,365.40	4,448.70
Cost of revenues:	'	'	'
Product	1,276.60	1,204	1,155.30
Service	451.1	452.6	424.8
Total cost of revenues	1,727.70	1,656.60	1,580.10
Gross margin	2,941.40	2,708.80	2,868.60
Operating expenses:	'	'	'
Research and development	1,043.20	1,101.60	1,026.80
Sales and marketing	1,075.90	1,045.50	1,005.20
General and administrative	217.3	206.8	187.5
Restructuring and other charges	39.1	46.8	30.6
Total operating expenses	2,375.50	2,400.70	2,250.10
Operating income	565.9	308.1	618.5
Other expense, net	-40.4	-16.6	-46.8
Income before income taxes and noncontrolling interest	525.5	291.5	571.7
Income tax provision	85.7	105	146.7
Consolidated net income	439.8	186.5	425
Adjust for net income attributable to noncontrolling interest	0	0	0.1
Net income attributable to Juniper Networks	$439.80	$186.50	$425.10
Net income per share attributable to Juniper Networks common stockholders:	'	'	'
Basic (in dollars per share)	$0.88	$0.36	$0.80
Diluted (in dollars per share)	$0.86	$0.35	$0.79
Shares used in computing net income per share:	'	'	'
Basic (in shares)	501.8	520.9	529.8
Diluted (in shares)	510.3	526.2	541.4

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]	'	'	'
Consolidated net income	$439.80	$186.50	$425
Available-for-sale securities:	'	'	'
Change in unrealized gains on available-for-sale securities, net of tax provision of ($37.9) and ($0.6) for 2013 and 2012, respectively	65.1	3.2	2.5	[1]
Reclassification adjustment for realized net gains on available-for- sale securities included in net income, net of tax provision of $0.4 and $0.2 for 2013 and 2012, respectively	-1	-1.2	-3.8	[1]
Net change in unrealized gains (losses) on available-for-sale securities, net of taxes	64.1	2	-1.3	[1]
Cash flow hedges:	'	'	'
Change in unrealized gains (losses) on cash flow hedges, net of tax benefit of $1.7 and $0.2 for 2013 and 2012, respectively	0.7	7.4	-7.9	[1]
Reclassification adjustment for realized (gains) losses included in net income, net of tax benefit of ($0.8) and ($1.0) for 2013 and 2012, respectively	-1.5	6.5	-0.7	[1]
Net change in unrealized (losses) gains on cash flow hedges, net of taxes	-0.8	13.9	-8.6	[1]
Change in foreign currency translation adjustments	-3.4	6.4	-6.4
Other comprehensive income (loss), net of tax	59.9	22.3	-16.3
Comprehensive income	499.7	208.8	408.7
Comprehensive loss attributable to noncontrolling interest	0	0	0.1
Comprehensive income attributable to Juniper Networks	$499.70	$208.80	$408.80
[1]	Taxes related to available-for-sale securities and cash flow hedges were not material for 2011.

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income Parenthetical (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]	'	'
Tax provision on change in unrealized gains on available-for-sale securities	($37.90)	($0.60)
Tax provision on reclassification adjustment for realized net gains on available-for-sale securities included in net income	0.4	0.2
Tax benefit on change in unrealized gains (losses) on cash flow hedges	1.7	0.2
Tax benefit on reclassification adjustment for realized losses (gains) included in net income	($0.80)	($1)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$2,284	$2,407.80
Short-term investments	561.9	441.5
Accounts receivable, net of allowance for doubtful accounts of $5.4 and $9.5 as of December 31, 2013 and 2012, respectively	578.3	438.4
Deferred tax assets, net	79.8	172.6
Prepaid expenses and other current assets	199.9	140.4
Total current assets	3,703.90	3,600.70
Property and equipment, net	882.3	811.9
Long-term investments	1,251.90	988.1
Restricted cash and investments	89.5	106.4
Purchased intangible assets, net	106.9	128.9
Goodwill	4,057.70	4,057.80
Other long-term assets	233.8	138.3
Total assets	10,326	9,832.10
Current liabilities:	'	'
Accounts payable	200.4	209.3
Accrued compensation	273.9	279.3
Deferred revenue	705.8	693.5
Other accrued liabilities	261.3	239.9
Total current liabilities	1,441.40	1,422
Long-term debt	999.3	999.2
Long-term deferred revenue	363.5	229.9
Long-term income tax payable	114.4	112.4
Other long-term liabilities	105.2	69.1
Total liabilities	3,023.80	2,832.60
Commitments and contingencies (Note 16)	'	'
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; 495.2 shares and 508.4 shares issued and outstanding as of December 31, 2013 and 2012, respectively	0	0
Additional paid-in capital	9,868.90	9,905.70
Accumulated other comprehensive income	64.6	4.7
Accumulated deficit	-2,631.30	-2,911.40
Total Juniper Networks stockholders' equity	7,302.20	6,999
Noncontrolling interest	0	0.5
Total stockholders' equity	7,302.20	6,999.50
Total liabilities and stockholders' equity	$10,326	$9,832.10

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets Parentheticals (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Consolidated Balance Sheet Parenthetical [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	495,200,000	508,400,000
Common stock - outstanding	495,200,000	508,400,000
Allowance for doubtful accounts receivable, current	$5.40	$9.50

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Cash flows from operating activities:	'		'		'
Consolidated net income	$439.80		$186.50		$425
Adjustments to reconcile consolidated net income to net cash provided by operating activities:	'		'		'
Non-cash share-based compensation expense	244.6		242.7		217.8
Depreciation, amortization, and accretion	189.9		187.9		170
Restructuring and other charges	47.5	[1]	99.7	[1]	30.6	[1]
Deferred income taxes	72.2		-18.2		7.2
(Gain) loss on investments, net	-11.3		-26.7		0.3
Excess tax benefits from share-based compensation	-1.9		-7.2		-45
Loss on disposal of fixed assets	1.4		0.6		0
Changes in operating assets and liabilities, net of effects from acquisitions:	'		'		'
Accounts receivable, net	-139.9		139.1		18.6
Prepaid expenses and other assets	-127.4		-29.2		28.5
Accounts payable	-9.5		-121.2		33.9
Accrued compensation	-5.4		54.8		-32.2
Income tax payable	-38.5		-7.5		53.2
Other accrued liabilities	34.9		-5.3		-3.4
Deferred revenue	145.9		-53.6		82.2
Net cash provided by operating activities	842.3		642.4		986.7
Cash flows from investing activities:	'		'		'
Purchases of property and equipment	-233.1		-348.7		-266.3
Purchases of available-for-sale investments	-1,776		-1,496.50		-2,297.30
Proceeds from sales of available-for-sale investments	1,135.60		894.2		1,281.20
Proceeds from maturities of available-for-sale investments	366.2		559.7		645.4
Purchases of trading investments	-3.7		-4.1		-5.2
Proceeds from the sales of privately-held investments	9.4		36.5		2.6
Purchases of privately-held investments	-41.3		-12.2		-35.7
Payment for business acquisitions, net of cash and cash equivalents acquired	-10		-139.4		-30.7
Purchase of licensed software	-10		-65.3		0
Changes in restricted cash	-1.5		-20.9		-1.2
Net cash used in investing activities	-564.4		-596.7		-707.2
Cash flows from financing activities:	'		'		'
Proceeds from issuance of common stock	141.7		99.1		346.9
Purchases and retirement of common stock	-577.8		-650.6		-548.6
Payment for capital lease obligation	-1.4		-1.4		0
Issuance of long-term debt, net	0		0		991.6
Customer financing arrangements	33.9		-2.6		-15.9
Excess tax benefits from share-based compensation	1.9		7.2		45
Net cash (used in) provided by financing activities	-401.7		-548.3		819
Net (decrease) increase in cash and cash equivalents	-123.8		-502.6		1,098.50
Cash and cash equivalents at beginning of period	2,407.80		2,910.40		1,811.90
Cash and cash equivalents at end of period	2,284		2,407.80		2,910.40
Supplemental disclosures of cash flow information:	'		'		'
Cash paid for interest, net of amounts capitalized	57.4		50.1		34.4
Cash paid (received) for income taxes, net	105.1		118.7		-2.1
Non-cash investing activities:	'		'		'
Issuance of common stock and equity awards assumed in business acquisitions	0		16.5		0
Property and equipment acquired under capital lease	0		3.7		0
Licensed software acquired	$0		$19		$0
[1]	Amount includes restructuring and other charges reported in cost of revenues and operating expenses.

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Stockholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Deficit [Member]	Noncontrolling Interest [Member]
In Millions, unless otherwise specified	USD ($)		USD ($)	USD ($)	USD ($)	USD ($)
Stockholders' equity, Beginning balance at Dec. 31, 2010	$6,608.80	'	$9,717.80	($1.30)	($3,108.30)	$0.60
Number of shares, Beginning balance at Dec. 31, 2010	'	525.4	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Consolidated net income (loss)	425	'	'	'	425.1	-0.1
Other comprehensive income (loss), net	-16.3	'	'	-16.3	'	'
Shares issued in connection with share-based compensation (in number of shares)	'	18.7	'	'	'	'
Shares issued in connection with share-based compensation	345.5	'	345.5	'	'	'
Repurchase and retirement of common stock and net issuances (in number of shares)	'	-17.7	'	'	'	'
Repurchase and retirement of common stock and net issuances	-548.6	'	-259.4	'	-289.2	'
Share-based compensation expense	217.8	'	217.8	'	'	'
Tax benefit from employee stock option plans	57.5	'	57.5	'	'	'
Stockholders' equity, Ending balance at Dec. 31, 2011	7,089.70	'	10,079.20	-17.6	-2,972.40	0.5
Number of shares, Ending balance at Dec. 31, 2011	'	526.4	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Consolidated net income (loss)	186.5	'	'	'	186.5	0
Other comprehensive income (loss), net	22.3	'	'	22.3	'	'
Shares issued in connection with share-based compensation (in number of shares)	'	12.2	'	'	'	'
Shares issued in connection with share-based compensation	99.2	'	99.2	'	'	'
Shares assumed In connection with business acquisition, shares (in number of shares)	'	5.8	'	'	'	'
Shares assumed in connection with business acquisitions	16.5	'	16.5	'	'	'
Repurchase and retirement of common stock and net issuances (in number of shares)	'	-36	'	'	'	'
Repurchase and retirement of common stock and net issuances	-650.6	'	-525.1	'	-125.5	'
Share-based compensation expense	242.7	'	242.7	'	'	'
Tax benefit from employee stock option plans	-6.8	'	-6.8	'	'	'
Stockholders' equity, Ending balance at Dec. 31, 2012	6,999.50	'	9,905.70	4.7	-2,911.40	0.5
Number of shares, Ending balance at Dec. 31, 2012	'	508.4	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'
Consolidated net income (loss)	439.8	'	'	'	439.8	'
Other comprehensive income (loss), net	59.9	'	'	59.9	'	'
Shares issued in connection with share-based compensation (in number of shares)	'	16	'	'	'	'
Shares issued in connection with share-based compensation	142.2	'	142.2	'	'	'
Dissolution of non-controlling interest	-0.5	'	'	'	'	-0.5
Repurchase and retirement of common stock and net issuances (in number of shares)	'	-29.2	'	'	'	'
Repurchase and retirement of common stock and net issuances	-577.8	'	-418.1	'	-159.7	'
Share-based compensation expense	244.9	'	244.9	'	'	'
Tax benefit from employee stock option plans	-5.8	'	-5.8	'	'	'
Stockholders' equity, Ending balance at Dec. 31, 2013	$7,302.20	'	$9,868.90	$64.60	($2,631.30)	$0
Number of shares, Ending balance at Dec. 31, 2013	'	495.2	'	'	'	'

Description_of_Business_and_Ba

Description of Business and Basis of Presentation (Notes)	12 Months Ended
	Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Description of Business and Basis of Presentation	'
	Description of Business and Basis of Presentation
	Description of Business
	Juniper Networks, Inc. (the “Company” or “Juniper”) designs, develops, and sells products and services for high-performance networks, which combine scale and performance with agility and efficiency, so customers can build the best networks for their businesses. The Company serves the high-performance networking requirements of global service providers, enterprises, governments, and research and public sector organizations that view the network as critical to their success.
	Basis of Presentation
	The Consolidated Financial Statements, which include the Company and its wholly-owned subsidiaries, are prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”). All inter-company balances and transactions have been eliminated. Certain amounts in the prior years' Consolidated Financial Statements have been reclassified to conform to the current year presentation.
	During 2013, the Company consolidated operational oversight and management of all security products within the Software Solutions Division ("SSD") segment. As a result of this product realignment, security products previously reported in the Platform Systems Division ("PSD") segment (including the Branch SRX, Branch Firewall, and J Series product families) are now reported in the SSD segment. In addition, the Company realigned its Contrail products from the PSD segment to the SSD segment. The Company reclassified the segment data for the prior years to conform to the current year 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 realignments.
	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 have been 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 terminate the joint venture and subsequently NSN 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.

Significant_Accounting_Policie

Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Significant Accounting Policies	'
	Significant Accounting Policies
	Cash, Cash Equivalents and Investments
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash on hand, demand deposits with banks, highly liquid investments in money market funds, commercial paper, government securities, certificates of deposit, and corporate debt securities, which are readily convertible into cash. All highly liquid investments purchased with original maturities of three months or less are classified as cash and cash equivalents.
	Investments in Available-for-Sale and Trading Securities
	The Company's investments in publicly-traded debt and equity securities are classified as available-for-sale. Available-for-sale investments are initially recorded at cost and periodically adjusted to fair value in the Consolidated Balance Sheets. Unrealized gains and losses on these investments are reported as a separate component of accumulated other comprehensive income. Realized gains and losses are determined based on the specific identification method and are reported in the Consolidated Statements of Operations.
	The Company periodically evaluates its investments to determine if impairment charges are required. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value has been less than the Company's cost basis, the investment's financial condition, and near-term prospects of the investee. If the Company determines that the decline in an investment's fair value is other than temporary, the difference is recognized as an impairment loss in its Consolidated Statements of Operations.
	The Company's non-qualified compensation plan is invested in mutual funds which are classified as trading securities and reported at fair value in the Consolidated Balance Sheets. The realized and unrealized holding gains and losses are reported in the Consolidated Statements of Operations.
	Privately-Held Investments
	The Company has privately-held investments, which are included in other long-term assets in the Consolidated Balance Sheets. These investments are carried at cost, adjusted for any impairment, as the Company does not have a controlling interest and does not have the ability to exercise significant influence over these companies. These investments are inherently high risk as the market for technologies or products manufactured by these companies are usually in their early stages at the time of the investment by the Company and such markets may never be significant. The Company measures the fair value of privately-held investments using an analysis of the financial conditions and near term prospects of the investees, including recent financing activities and their capital structure. Realized gains and losses, if any, are reported in the Consolidated Statements of Operations.
	Fair Value
	Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it transacts, and considers assumptions that market participants would use when pricing the asset or liability. The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. These inputs are valued using market based approaches.
	Level 3 – Inputs are unobservable inputs based on the Company’s assumptions. These inputs, if any, are valued using internal financial models.
	Derivatives
	The Company uses derivatives to partially offset its market exposure to fluctuations in certain foreign currencies. The Company does not enter into derivatives for speculative or trading purposes.
	The Company uses foreign currency forward or option contracts to hedge certain forecasted foreign currency transactions relating to operating expenses. 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. These derivatives are carried at fair value and 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 costs 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, on its 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.
	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 Consolidated Statements of Operations. Changes in the fair value of these derivatives are largely offset by remeasurement of the underlying assets and liabilities. Cash flows from such derivatives are classified as operating activities. These foreign exchange forward contracts have maturities of one year or less.
	Inventory
	Inventory consists primarily of component parts to be used in the manufacturing process and is stated at the lower of cost or market. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. A charge is recorded to cost of product when inventory is determined to be in excess of anticipated demand or considered obsolete. The point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in the newly established cost basis.
	Property and Equipment
	Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets:
		Estimated Useful Life (years)
	Computers, equipment, and software	3 to 5
	Furniture and fixtures	5
	Building and building improvements	7 to 40
	Land improvements	10 to 40
	Leasehold improvements	Lease term, not to exceed 10 years
	Construction in progress is related to the construction or development of property and equipment that have not yet been placed in service for their intended use. Depreciation for equipment commences once it is placed in service and depreciation for buildings and leasehold improvements commences once they are ready for their intended use.
	Effective April 1, 2013, the Company extended the useful lives of certain computers and equipment based on 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. During the year ended December 31, 2013, this change in accounting estimate decreased depreciation expense by approximately $28.3 million or $0.04 per diluted share.
	Goodwill and Other Long-Lived Assets
	Goodwill represents the future economic benefits arising from other assets acquired in a business combination or an acquisition that are not individually identified and separately recorded. The excess of the purchase price over the estimated fair value of net assets of businesses acquired in a business combination is recognized as goodwill. Goodwill is tested for impairment annually during the fourth quarter or more frequently if certain indicators are present. Other intangible assets acquired in a business combination and determined to have an indefinite useful life are not amortized but are assessed for potential impairment annually or when events or circumstances indicate that their carrying amounts might be impaired.
	The Company performs its annual goodwill impairment analysis at its reporting unit level, which may be one level below its operating segment level during the fourth quarter of each year or more frequently if certain indicators are present. The fair value of the Company's reporting units is determined using both the income and market valuation approaches. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows that the reporting unit is expected to generate over its remaining life. Under the market approach, the value of the reporting unit is based on an analysis that compares the value of the reporting unit to values of publicly traded companies in similar lines of business. In the application of the income and market valuation approaches, the Company is required to make estimates of future operating trends and judgments on discount rates and other variables. Actual future results related to assumed variables could differ from these estimates.
	Long-lived assets, such as property, plant, and equipment, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset, or asset group, to estimated undiscounted future cash flows expected to be generated by the asset, or asset group. An impairment charge is recognized by the amount by which the carrying amount of the asset, or asset group, exceeds its fair value.
	The Company amortizes intangible assets with estimable useful lives on a straight-line basis over their useful lives.
	Revenue Recognition
	Revenue is recognized when all of the following criteria have been met:
	•	Persuasive evidence of an arrangement exists. The Company generally relies upon sales contracts or agreements, and customer purchase orders to determine the existence of an arrangement.
	•	Delivery has occurred. The Company uses shipping terms and related documents, or written evidence of customer acceptance, when applicable, to verify delivery or performance.
	•	Sales price is fixed or determinable. The Company assesses whether the sales price is fixed or determinable based on the payment terms and whether the sales price is subject to refund or adjustment.
	•	Collectability is reasonably assured. The Company assesses collectability based on creditworthiness of customers as determined by its credit checks, their payment histories, or changes in circumstances that indicate that collectability is not reasonably assured.
	When sales arrangements contain multiple elements, including software and non-software components that function together to deliver the tangible products' essential functionality, the Company allocates revenue to each element based on a selling price hierarchy. The selling price for a deliverable is based on either vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”) if VSOE is not available, or estimated selling price (“ESP”) if neither VSOE nor TPE is available. The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. VSOE of selling price is based on the price charged when the element is sold separately. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonable range based on historical discounting trends for specific products and services. TPE of selling price is established by evaluating largely interchangeable competitor products or services in stand-alone sales to similarly situated customers. However, as the Company's products contain a significant element of proprietary technology and its solutions offer substantially different features and functionality, the comparable pricing of third-party products with similar functionality typically cannot be obtained. ESP is established considering multiple factors including, but not limited to pricing practices in different geographies and through different sales channels, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles.
	In multiple element arrangements where software deliverables are included, revenue is allocated to each separate unit of accounting for each of the non-software deliverables and to the software deliverables as a group using the relative selling prices of each of the deliverables in the arrangement based on the aforementioned selling price hierarchy. If the arrangement contains more than one software deliverable, the arrangement consideration allocated to the software deliverables as a group is then allocated to each software deliverable using the residual method when VSOE of fair value of the undelivered items exists. Under the residual method, the amount of revenue allocated to delivered elements equals the total arrangement consideration less the aggregate fair value of any undelivered elements. If VSOE of one or more undelivered items does not exist, revenue from the entire arrangement is deferred and recognized at the earlier of: (i) delivery of those elements or (ii) when fair value can be established unless maintenance services is the only undelivered element, in which case, the entire arrangement fee is recognized ratably over the maintenance service period.
	The Company limits the amount of revenue recognition for delivered elements to the amount that is not contingent on the future delivery of products or services or subject to customer-specific return or refund privileges.
	The Company records reductions to revenue for estimated product returns and pricing adjustments, such as rebates and price protection, in the same period that the related revenue is recorded. The amount of these reductions is based on historical sales returns and price protection credits, specific criteria outlined in rebate agreements, and other factors known at the time.
	A portion of the Company's sales is made through distributors under agreements allowing for pricing credits or rights of return. As reliable estimates of these credits or returns cannot be made, product revenue on sales made through these distributors is recognized upon sell-through as reported by the distributors to the Company. Deferred revenue on shipments to distributors reflects the effects of distributor pricing credits given and the amount of gross margin expected to be realized upon sell-through. Deferred revenue is recorded net of the related product costs of revenue.
	Service revenues include revenue from maintenance, training, and professional services. Maintenance is offered under renewable contracts. Revenue from maintenance service contracts is deferred and recognized ratably over the contractual support period, which is generally one to three years. Revenue from training and professional services is recognized as services are completed or ratably over the contractual period, which is generally one year or less.
	Allowance for Doubtful Accounts
	The allowance for doubtful accounts is based on the Company's assessment of the collectability of customer accounts. The Company regularly reviews its receivables that remain outstanding past their applicable payment terms and establishes an allowance by considering factors such as historical experience, credit quality, age of the accounts receivable balances, and current economic conditions that may affect a customer's ability to pay.
	Warranty Reserves
	The Company generally offers a one-year warranty on all of its hardware products, a 90-day warranty on the media that contains the software embedded in the products. Warranty costs are recognized as part of the Company's cost of sales based on associated material costs, labor costs, and overhead at the time revenue is recognized. Material costs are estimated primarily based upon the historical costs to repair or replace product returns within the warranty period. Labor and overhead costs are estimated primarily based upon historical trends in the cost to support customer cases within the warranty period.
	Contract Manufacturer Liabilities
	The Company establishes a liability for non-cancelable, non-returnable purchase commitments with its contract manufacturers for carrying charges, quantities in excess of its demand forecasts, or obsolete material charges for components purchased by the contract manufacturers to meet the Company’s demand forecast or customer orders. The demand forecasts are based upon historical trends and analysis from the Company's sales and marketing organizations, adjusted for overall market conditions.
	Research and Development
	Costs to research, design, and develop the Company's products are expensed as incurred.
	Software Development Costs
	Capitalization of software development costs for software to be sold, leased, or otherwise marketed begins when a product's technological feasibility has been established and ends when a product is available for general release to customers. Generally, the Company's products are released soon after technological feasibility has been established. As a result, costs incurred between achieving technological feasibility and product general availability have not been significant. The Company capitalizes costs associated with internal-use software systems that have reached the application development stage and are primarily attributable to the Company's enterprise resource planning ("ERP") implementation. Such capitalized costs include external direct costs utilized in developing or obtaining the applications and payroll and payroll-related costs for employees, who are directly associated with the development of the applications.
	Advertising
	Advertising costs are charged to sales and marketing expense as incurred. Advertising expense was $20.1 million, $20.0 million, and $17.2 million, for 2013, 2012, and 2011, respectively.
	Foreign Currency
	Assets and liabilities of foreign operations with non-U.S. Dollar functional currency are translated to U.S. Dollars using exchange rates in effect at the end of the period. Revenue and expenses are translated to U.S. Dollars using average exchange rates for the period. The resulting translation adjustments are included in the Company’s Consolidated Balance Sheets in the stockholders’ equity section as a component of accumulated other comprehensive income. For the Company’s international subsidiaries in which the functional currency is the U.S. dollar, the Company records foreign exchange gains and losses for assets and liabilities in the Consolidated Statements of Operations. Remeasurement adjustments are recorded in other expense, net in the Consolidated Statements of Operations.
	Loss Contingencies
The Company is subject to the possibility of various loss contingencies arising in the ordinary course of business. Management considers the likelihood of loss related to an asset, or the incurrence of a liability, as well as its ability to reasonably estimate the amount of loss, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required.
Share-Based Compensation
The Company utilizes the Black-Scholes-Merton (“BSM”) option-pricing model to estimate the fair value of its stock options and Employee Stock Purchase Plan ("ESPP") shares. The Company determines the fair value of its restricted stock units ("RSUs"), restricted stock awards ("RSAs"), and performance share awards ("PSAs") based on the closing market price of the Company’s common stock on the date of grant. Share-based compensation expense is based on the fair value of the underlying awards and amortized on a straight-line basis, net of estimated forfeitures. With respect to PSAs, that generally vest after three years, for the portion of the award attributable to each performance year, the Company recognizes PSA expense on a straight-line basis over the remaining vesting period starting in the period in which the annual performance targets are set for each such performance year, to the extent that the performance target is expected to be met.
The BSM model requires various highly subjective assumptions that represent management's best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The expected volatility is based on the implied volatility of market-traded options on the Company's common stock, adjusted for other relevant factors including historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected life of the Company’s stock options. The expected life of a stock option award is based on historical experience.
Provision for Income Taxes
Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax bases of assets and liabilities and their reported amounts. Valuation allowances are recorded to reduce deferred tax assets to the amount that will more likely than not be realized.
The Company accounts for uncertainty in income taxes using a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company classifies the liability for unrecognized tax benefits as current to the extent that the Company anticipates payment (or receipt) of cash within one year. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes.
Concentrations of Risk
Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments, and accounts receivable. The Company invests only in high-quality credit instruments and maintains its cash, cash equivalents and available-for-sale investments in fixed income securities with several high-quality institutions. Deposits held with banks, including those held in foreign branches of global banks, may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand and, therefore, bear minimal credit risk.
The Company’s derivatives expose it to credit risk to the extent that counterparties may be unable to meet the terms of the agreement. To mitigate concentration of risk related to its derivatives, the Company establishes counterparty limits to major credit-worthy financial institutions. In addition, the potential risk of loss with any one counterparty resulting from this type of credit risk is monitored and the derivatives transacted with these entities are relatively short in duration. Therefore, the Company does not expect material losses as a result of defaults by counterparties.
Generally, credit risk with respect to accounts receivable is diversified due to the number of entities comprising the Company's customer base and their dispersion across different geographic locations throughout the world. The Company performs ongoing credit evaluations of its customers and generally does not require collateral on accounts receivable. During the years ended December 31, 2013 and December 31, 2011, no single customer accounted for 10% or more of net revenues. During the year ended December 31, 2012, Verizon Communications, Inc. ("Verizon") accounted for 10.3% of net revenues.
The Company relies on sole suppliers for certain of its components such as application-specific integrated circuits ("ASICs") and custom sheet metal. Additionally, the Company relies primarily on a limited number of significant independent contract manufacturers for the production of its products. The inability of any supplier or manufacturer to fulfill supply requirements of the Company could negatively impact future operating results.
Use of Estimates
The preparation of the financial statements and related disclosures in conformity with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the Consolidated Financial Statements and the accompanying notes. The Company bases its estimates and assumptions on current facts, historical experience, and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. To the extent there are material differences between the Company's estimates and the actual results, the Company's future consolidated results of operation may be affected.
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.

Business_Combinations_Notes

Business Combinations (Notes)	12 Months Ended
	Dec. 31, 2013
Business Combinations [Abstract]	'
Business Combinations	'
	Business Combinations
	The Company's Consolidated Financial Statements include the operating results of acquired businesses from the date of each acquisition. Pro forma results of operations for these acquisitions have not been presented as the financial impact to the Company's consolidated results of operations, both individually and in aggregate, is not material. Additional information, if any, existing as of the acquisition dates but unknown to the Company may become known during the remainder of the measurement period, not to exceed 12 months from the acquisition date, which may result in changes to the amounts and allocations recorded.
	The Company completed one business combination in 2013, three business combinations in 2012, and two business combinations in 2011 for cash consideration including the fair value of vested share-based awards assumed, if any, of approximately $10.0 million, $187.3 million, and $30.5 million, respectively.
	The following table presents the purchase consideration allocations for these acquisitions based upon acquisition-date fair values, including cash and cash equivalents acquired (in millions):
		2013 Acquisitions				2012 Acquisitions			2011 Acquisitions
	Net tangible assets acquired	$	0.1			$	3.5		$	1.7
	Intangible assets acquired	9.9				54.1			28.4
	Goodwill	—				129.7			0.4
	Total	$	10			$	187.3		$	30.5
	The Company recognized $0.9 million, $2.0 million, and $9.6 million of acquisition-related costs during the years ended December 31, 2013, 2012, and 2011, respectively. These acquisition-related costs were expensed in the period incurred as general and administrative expenses in the Consolidated Statements of Operations.
	The goodwill recognized for the 2012 and 2011 acquisitions was primarily attributable to expected synergies and was not deductible for U.S. federal income tax purposes.
	2013 Acquisition
	During 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. Intangible assets acquired consisted of existing technology with a weighted-average estimated useful life of five years.
	2012 Acquisitions
	Contrail
	On December 14, 2012, the Company acquired the remaining ownership interest in Contrail, increasing its ownership from 12% to 100%, in a cash and stock transaction for approximately $91.7 million. Contrail, a privately-held software networking company, provides software-defined networking solutions technology that augments Juniper's portfolio of products and services.
	The aggregate consideration of $91.7 million was allocated as follows: net tangible assets acquired of $3.6 million, including cash and cash equivalents of $8.6 million; intangible assets of $17.4 million; and recognized goodwill of $70.7 million, which was assigned to the Company's PSD segment. Refer to Note 7, Goodwill and Purchased Intangible Assets, for discussion of the reclassification of goodwill from its PSD segment to its SSD segment related to this acquisition.
	The Company previously accounted for its investment in Contrail at cost, which was $3.0 million prior to the acquisition. As of the acquisition date, the fair value of the Company's previous equity interest in Contrail was remeasured to its fair value of $17.7 million, which was based upon adjustments market participants would consider when estimating the fair value of the previously held interest in Contrail. This resulted in a $14.7 million gain, which was reported within other expense, net in the Consolidated Statements of Operations.
	Mykonos Software, Inc.
	On February 13, 2012, the Company acquired 100% of the equity securities of Mykonos Software, Inc. ("Mykonos") for $82.6 million in cash. The acquisition of Mykonos extended Juniper Networks' security portfolio with an intrusion deception system capable of detecting an attacker before an attack is in process. In connection with this acquisition, the Company acquired net tangible liabilities of $0.2 million, intangible assets of $24.3 million, and recognized goodwill of $58.5 million, which was assigned to the Company's SSD segment.
	BitGravity, Inc.
	On March 8, 2012, the Company acquired a source code license and patent joint-ownership related to the service management layer of BitGravity, Inc.'s ("BitGravity") Content Delivery Network ("CDN") technology for $13.0 million in cash. In connection with this acquisition, the Company acquired net tangible assets of $0.1 million, intangible assets of $12.4 million, and recognized goodwill of $0.5 million, which was assigned to the Company's SSD segment.
	Intangible Assets Acquired
	The following table presents details of the intangible assets acquired for the business combinations completed during 2012 as of their respective acquisition dates (in millions, except years):
		Contrail						Mykonos			BitGravity
		Weighted		Amount				Weighted	Amount		Weighted	Amount
		Average						Average			Average
		Estimated						Estimated			Estimated
		Useful						Useful			Useful
		Life						Life			Life
		(In Years)						(In Years)			(In Years)
	Existing technology	—		$	—			6	$	19.3	3	$	12.4
	Trade name and trademarks	—		—				7	1		—	—
	In-process research and development	N/A		17.4				N/A	4		—	—
	Total	—		$	17.4			6	$	24.3	3	$	12.4
	Acquired in-process research and development (“IPR&D”) consists of existing research and development projects at the time of the acquisition. Projects that qualify as IPR&D assets represent those that have not yet reached technological feasibility and have no alternative future use. After initial recognition, acquired IPR&D assets are accounted for as indefinite-lived intangible assets. Development costs incurred after acquisition on acquired development projects are expensed as incurred. Upon completion of development, acquired IPR&D assets are considered amortizable intangible assets. If the IPR&D project is abandoned, the Company writes off the related purchased intangible asset in the period it is abandoned.
	2011 Acquisitions
	OpNext
	On February 9, 2011, the Company acquired certain IP assets of OpNext for $26.0 million in cash, which was accounted for as a business combination. The acquisition of OpNext's ASIC technology furthered Juniper's next-generation development of converged packet optical solutions for the Company's service provider customers. In connection with this acquisition, the Company acquired the fair value of intangible assets of $25.7 million and recognized goodwill of $0.3 million.
	Brilliant
	On February 18, 2011, the Company acquired certain assets of Brilliant, including all the intellectual property ("IP") for $4.5 million in cash. This IP assisted the Company in extending its market position by delivering solutions that offer greater flexibility for service providers as they deployed 3G and 4G networks. In connection with this acquisition, the Company acquired net tangible assets of $1.7 million, intangible assets of $2.7 million, and recognized goodwill of $0.1 million.
	Intangible Assets Acquired
	The following table presents details of the intangible assets acquired for the business combinations completed during 2011 as of their respective acquisition dates (in millions, except years):
		OpNext						Brilliant
		Weighted Average		Amount				Weighted Average	Amount
		Estimated Useful						Estimated Useful
		Life (In Years)						Life (In Years)
	Existing or core technology	10		$	20.6			5	$	1.3
	Support agreements and related relationships	4		5.1				—	—
	Patents	—		—				5	1.4
	Total	9		$	25.7			5	$	2.7

Cash_Equivalents_and_Investmen

Cash Equivalents and Investments (Notes)	12 Months Ended
	Dec. 31, 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 December 31, 2013 and December 31, 2012 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of December 31, 2013
	Fixed income securities:
	Asset-backed securities	$	249.9	$	0.1		$	(0.1	)	$	249.9
	Certificates of deposit	27.6		—			—			27.6
	Commercial paper	6.9		—			—			6.9
	Corporate debt securities	813.6		2			(0.3		)	815.3
	Foreign government debt securities	10.7		—			—			10.7
	Government-sponsored enterprise obligations	306.2		0.1			(0.1		)	306.2
	U.S. government securities	303.3		0.1			(0.1		)	303.3
	Total fixed income securities	1,718.20		2.3			(0.6		)	1,719.90
	Money market funds	1,043.70		—			—			1,043.70
	Mutual funds	3.9		0.1			—			4
	Publicly-traded equity securities	12		104.5			(1.9		)	114.6
	Total available-for-sale securities	2,777.80		106.9			(2.5		)	2,882.20
	Trading securities in mutual funds(*)	15.4		—			—			15.4
	Total	$	2,793.20	$	106.9		$	(2.5	)	$	2,897.60
	Reported as:
	Cash equivalents	$	996.2	$	—		$	—		$	996.2
	Restricted investments	87.5		0.1			—			87.6
	Short-term investments	459		104.9			(2.0		)	561.9
	Long-term investments	1,250.50		1.9			(0.5		)	1,251.90
	Total	$	2,793.20	$	106.9		$	(2.5	)	$	2,897.60
	________________________________
	(*)	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
	Fixed income securities:
	Asset-backed securities	$	226.2	$	0.3		$	(0.1	)	$	226.4
	Certificates of deposit	42.5		—			—			42.5
	Commercial paper	22.4		—			—			22.4
	Corporate debt securities	533.4		2.3			(0.1		)	535.6
	Foreign government debt securities	5		—			—			5
	Government-sponsored enterprise obligations	270.7		0.3			—			271
	U.S. government securities	494.4		0.1			—			494.5
	Total fixed income securities	1,594.60		3			(0.2		)	1,597.40
	Money market funds	1,145.20		—			—			1,145.20
	Mutual funds	2.9		0.1			—			3
	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 fixed income securities as of December 31, 2013 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	Due within one year	$	467.7	$	0.3		$	—		$	468
	Due between one and five years	1,250.50		2			(0.6		)	1,251.90
	Total	$	1,718.20	$	2.3		$	(0.6	)	$	1,719.90
	The Company had 178 and 98 investments in unrealized loss positions as of December 31, 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 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 not 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 December 31, 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 year ended December 31, 2013, 2012, and 2011.
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 years ended December 31, 2013, 2012, and 2011, 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 years ended December 31, 2013, 2012, and 2011.
The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of December 31, 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 December 31, 2013
Fixed income securities:
Asset-backed securities(1)	$	153	$	(0.1	)	$	0.6		$	—	$	153.6	$	(0.1	)
Corporate debt securities(1)	156.1		(0.3		)	9.7			—		165.8		(0.3		)
Foreign government debt securities(2)	10		—			—			—		10		—
Government-sponsored enterprise obligations	123.1		(0.1		)	—			—		123.1		(0.1		)
U.S. government securities	119.7		(0.1		)	—			—		119.7		(0.1		)
Total fixed income securities	561.9		(0.6		)	10.3			—		572.2		(0.6		)
Publicly-traded equity securities	6.8		(1.9		)	—			—		6.8		(1.9		)
Total available-for sale securities	$	568.7	$	(2.5	)	$	10.3		$	—	$	579	$	(2.5	)
________________________________
(1) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2013.
(2) Balance for less than 12 months include investments that were in an immaterial unrealized loss position as of December 31, 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 (1)	$	55.1	$	(0.1	)	$	0.1		$	—	$	55.2	$	(0.1	)
Certificates of deposit(2)	0.3		—			—			—		0.3		—
Commercial paper(2)	10		—			—			—		10		—
Corporate debt securities	116		(0.1		)	—			—		116		(0.1		)
Government-sponsored enterprise obligations(2)	30		—			—			—		30		—
U.S. government securities(2)	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	)
________________________________
(1) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2012.
(2) Balance for less than 12 months include 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 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.
Privately-Held Investments
As of December 31, 2013 and December 31, 2012, the carrying values of the Company’s privately-held investments of $57.2 million and $32.0 million, respectively, were included in other long-term assets in the Consolidated Balance Sheets. During 2013, certain privately-held investments with carrying values of $12.2 million became public and were reclassified to short-term investments and resulted in net unrealized gains of $102.7 million and recorded as a component of accumulated comprehensive income in the 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.
During the years ended December 31, 2013, 2012, and 2011, the Company determined that certain privately-held investments were other-than-temporarily impaired, resulting in impairment charges of $2.8 million, $20.0 million, and $1.8 million, respectively, that were recorded within other expense, net in the Consolidated Statements of Operations.

Fair_Value_Measurements_Notes

Fair Value Measurements (Notes)	12 Months Ended
	Dec. 31, 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 Consolidated Balance Sheets (in millions):
		Fair Value Measurements at December 31, 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	$	—	$	249.9		$	—	$	249.9
	Certificates of deposit	—		27.6			—		27.6
	Commercial paper	—		6.9			—		6.9
	Corporate debt securities	—		815.3			—		815.3
	Foreign government debt securities	—		10.7			—		10.7
	Government-sponsored enterprise obligations	—		306.2			—		306.2
	Money market funds (1)	1,043.70		—			—		1,043.70
	Mutual funds (2)	4		—			—		4
	Publicly-traded equity securities	114.6		—			—		114.6
	U.S. government securities	197.2		106.1			—		303.3
	Total available-for-sale securities	1,359.50		1,522.70			—		2,882.20
	Trading securities in mutual funds (3)	15.4		—			—		15.4
	Derivative assets:
	Foreign exchange contracts	—		3			—		3
	Total assets measured at fair value	$	1,374.90	$	1,525.70		$	—	$	2,900.60
	Liabilities measured at fair value:
	Derivative liabilities:
	Foreign exchange contracts	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total liabilities measured at fair value	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total assets measured at fair value, reported as:
	Cash equivalents	$	965.1	$	31.1		$	—	$	996.2
	Restricted investments	87.6		—			—		87.6
	Short-term investments	246.5		315.4			—		561.9
	Long-term investments	75.7		1,176.20			—		1,251.90
	Prepaid expenses and other current assets	—		3			—		3
	Total assets measured at fair value	$	1,374.90	$	1,525.70		$	—	$	2,900.60
	Total liabilities measured at fair value, reported as:
	Other accrued liabilities	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total liabilities measured at fair value	$	—	$	(0.7	)	$	—	$	(0.7	)
	________________________________
	(1)	Balance includes $83.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisitions 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 the 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 the 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 derivative instruments are classified as Level 2, as they are not actively traded and are valued using pricing models that use observable market inputs. 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 circumstances resulted in a transfer. During the year ended December 31, 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 year ended December 31, 2013, the Company had no transfers to Level 3. During the year ended December 31, 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 estimates 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. Purchased intangible assets are measured at fair value primarily using discounted cash flow projections.
The following table presents assets measured at fair value on a nonrecurring basis and the related impairment losses included in the Consolidated Statements of Operations (in millions):
	As of December 31,
	2013					2012
	Fair Value		Losses			Fair Value		Losses
Privately-held investments	$	2	$	(2.8	)	$	—	$	(20.0	)
Purchased intangible assets, net	$	—	—			$	—	(5.4		)
Total losses for nonrecurring basis			$	(2.8	)			$	(25.4	)
These assets were classified as Level 3 assets due to the absence of quoted market prices and/or inherent lack of liquidity.
As of December 31, 2013 and 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. As of December 31, 2013 and December 31, 2012, the estimated fair value of the Company’s long-term debt was approximately $1,023.5 million and $1,090.7 million, respectively, based on quoted market prices (Level 1).

Derivative_Instruments_Notes

Derivative Instruments (Notes)	12 Months Ended
	Dec. 31, 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 December 31,
		2013		2012
	Cash flow hedges	$	137.6	$	85.8
	Non-designated derivatives	144.4		112.8
	Total	$	282	$	198.6
	Cash Flow Hedges
	The Company uses foreign currency forward or option contracts to hedge 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.
	See Note 5, Fair Value Measurements, for the fair values of the Company’s derivative instruments in the Consolidated Balance Sheets.
	As of December 31, 2013, the Company recognized a loss of $1.0 million in accumulated other comprehensive income for the effective portion of its derivative instruments and reclassified a gain of $0.7 million during the year ended December 31, 2013 from other comprehensive income to operating expense in the Consolidated Statements of Operations. As of December 31, 2012, the Company recognized a gain of $7.2 million in accumulated other comprehensive income for the effective portion of its derivative instruments and reclassified a loss of $7.5 million during the year ended December 31, 2012 from other comprehensive income to operating expense in the Consolidated Statements of Operations. As of December 31, 2011, the Company recognized a loss of $7.9 million in accumulated other comprehensive income for the effective portion of its derivative instruments and reclassified a gain of $0.7 million during the year ended December 31, 2011 from other comprehensive income to operating expense in the Consolidated Statements of Operations.
	The ineffective portion of the Company's derivative instruments recognized in its Consolidated Statements of Operations was not material during the years ended December 31, 2013, 2012, and 2011.
	Non-Designated Derivatives
	During the years ended December 31, 2013, 2012, and 2011, the Company recognized a net gain of $0.9 million, a net gain of $1.0 million, and a gain of $1.5 million, respectively, on non-designated derivative instruments within other expense, net, in its Consolidated Statements of Operations.
	Offsetting of Derivatives
	The Company presents its derivative assets and derivative liabilities on a gross basis in the 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 December 31, 2013 and December 31, 2012, the potential effect of rights of setoff associated with derivative instruments was not material. 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)	12 Months Ended
	Dec. 31, 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 (in millions):
		PSD			SSD			Total
	December 31, 2011	$	1,795.60		$	2,132.50		$	3,928.10
	Additions due to business combinations	70.7			59.6			130.3
	Adjustments to goodwill	—			(0.6		)	(0.6		)
	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		)
	31-Dec-13	$	1,616.60		$	2,441.10		$	4,057.70
	The additions to goodwill in 2012 were based on the purchase price allocations of the acquisitions completed during 2012. The adjustments to goodwill during 2012 were related to adjustments to net tangible assets assumed from certain businesses acquired in 2010 and 2011. The Company also recorded adjustments to net tangible assets assumed related to the acquisitions completed in 2012.
	During 2013, goodwill of $179.0 million associated with security products previously reported under the PSD segment was reclassified to the SSD segment in connection with the Company's product realignment of all security products. In addition, the Company realigned its Contrail products from the PSD segment to the SSD segment resulting in a reclassification of goodwill of $70.6 million. Goodwill was reclassified based on the relative fair value allocation of the reporting units affected.
	There were no impairments to goodwill during the years ended December 31, 2013, 2012, and 2011.
	Purchased Intangible Assets
	The Company’s purchased intangible assets were as follows (in millions):
		Gross			Accumulated			Impairments and			Net
					Amortization			Other Charges
	As of December 31, 2013
	Intangible assets with finite lives:
	Technologies and patents	$	581.4		$	(453.4	)	$	(30.5	)	$	97.5
	Customer contracts, support agreements, and	74.3			(62.7		)	(2.2		)	9.4
	related relationships
	Total purchased intangible assets	$	655.7		$	(516.1	)	$	(32.7	)	$	106.9
	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
	Total intangible assets with finite lives	628.4			(484.2		)	(32.7		)	111.5
	IPR&D with indefinite lives	17.4			—			—			17.4
	Total purchased intangible assets	$	645.8		$	(484.2	)	$	(32.7	)	$	128.9
	During 2013, research and development efforts were completed and IPR&D accounted for as an indefinite-lived asset was reclassified as an amortizable finite-lived asset.
	The following table presents the amortization of intangible assets included in the Consolidated Statements of Operations (in millions):
		Years Ended December 31,
		2013			2012			2011
	Cost of revenues	$	27.3		$	27.6		$	21.7
	Operating expenses:
	Sales and marketing	3.4			3.5			4.1
	General and administrative	1.2			1.2			1.3
	Total operating expenses	4.6			4.7			5.4
	Total	$	31.9		$	32.3		$	27.1
	In connection with the restructuring plan in 2012 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. These assets were measured at fair value primarily using discounted cash flow projections. Additionally, the Company determined 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 year ended December 31, 2012, which were included in cost of revenues in the Consolidated Statements of Operations. There were no impairment charges to purchased intangible assets during the years ended December 31, 2013 and 2011.
	As of December 31, 2013, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):
	Years Ending December 31,	Amount
	2014	$	36.2
	2015	32.6
	2016	18.5
	2017	10.5
	2018	3.7
	Thereafter	5.4
	Total	$	106.9

Other_Financial_Information_No

Other Financial Information (Notes)	12 Months Ended
	Dec. 31, 2013
Other Financial Information [Abstract]	'
Other Financial Information	'
	Other Financial Information
	Inventories
	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 are reported within prepaid expenses and other current assets and other long-term assets in the Consolidated Balance Sheets and consisted of the following (in millions):
		As of December 31,
		2013			2012
	Production materials	$	51.3		$	53.1
	Finished goods	1.4			4.1
	Inventories	$	52.7		$	57.2
	During the year ended December 31, 2012, the Company recorded charges of $44.3 million, to cost of revenues, representing inventory held in excess of forecasted demand, of which $36.3 million was in connection with the restructuring plan in 2012 discussed in Note 9, Restructuring and Other Charges.
	Property and Equipment, Net
	Property and equipment, net, consisted of the following (in millions):
		As of December 31,
		2013			2012
	Computers and equipment	$	794.6		$	711.8
	Software	108.4			106.6
	Leasehold improvements	202.6			206.5
	Furniture and fixtures	42.5			28.7
	Building and building improvements	242.6			206.1
	Land and land improvements	238.9			208.2
	Construction-in-process	79.5			112.7
	Property and equipment, gross	1,709.10			1,580.60
	Accumulated depreciation	(826.8		)	(768.7		)
	Property and equipment, net	$	882.3		$	811.9
	Depreciation expense was $148.2 million, $154.7 million, and $142.2 million in 2013, 2012, and 2011, respectively. Property and equipment is periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. In 2011, the Company recorded a $13.5 million asset impairment charge in restructuring and other charges in the Consolidated Statement of Operations related to an abandoned in-process internal use software project.
	Other Long-Term Assets
	Other long-term assets consisted of the following (in millions):
		As of December 31,
		2013			2012
	Privately-held investments	$	57.2		$	32
	Licensed software	90.4			84.4
	Federal income tax receivable	20			—
	Financed customer receivable	19.9			—
	Inventory	15.2			—
	Prepaid costs, deposits, and other	31.1			21.9
	Other long-term assets	$	233.8		$	138.3
	Warranties
	The Company accrues for warranty costs based on associated material, labor for customer support, and overhead at the time revenue is recognized. This accrual is reported as accrued warranty within current liabilities in the Consolidated Balance Sheets. Changes in the Company’s warranty reserve were as follows (in millions):
		As of December 31,
		2013			2012
	Beginning balance	$	29.7		$	28.3
	Provisions made during the period, net	28.8			31.9
	Adjustments related to pre-existing warranties	(2.1		)	—
	Actual costs incurred during the period	(28.4		)	(30.5		)
	Ending balance	$	28		$	29.7
	Deferred Revenue
	Details of the Company's deferred revenue, as reported in the Consolidated Balance Sheets, were as follows (in millions):
		As of December 31,
		2013			2012
	Deferred product revenue:
	Undelivered product commitments and other product deferrals	$	184.9		$	256.9
	Distributor inventory and other sell-through items	118.7			138.4
	Deferred gross product revenue	303.6			395.3
	Deferred cost of product revenue	(58.6		)	(99.4		)
	Deferred product revenue, net	245			295.9
	Deferred service revenue	824.3			627.5
	Total	$	1,069.30		$	923.4
	Reported as:
	Current	$	705.8		$	693.5
	Long-term	363.5			229.9
	Total	$	1,069.30		$	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):
	Years Ended December 31,
	2013			2012			2011
Interest income	$	8.7		$	11		$	9.7
Interest expense	(58.4		)	(52.9		)	(49.5		)
Other	9.3			25.3			(7.0		)
Other expense, net	$	(40.4	)	$	(16.6	)	$	(46.8	)
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.
For the years ended December 31, 2013, 2012 and 2011, interest expense included $45.2 million, net of $1.9 million capitalized, $40.0 million, net of $7.1 million capitalized, and $37.7 million, net of $1.2 million capitalized, respectively, related to the Company's outstanding long-term debt issued in March 2011 (Refer to Note 10, Long-Term Debt and Financing).
In 2013, Other was primarily comprised of net gains of $7.1 million, related to its privately-held investments and publicly-traded equity investments. In 2012, Other included recognized gains of $45.5 million, including a $14.7 million gain from the acquisition of its privately-held investment in Contrail, and impairment losses of $20.0 million related to its privately-held investments. In 2011, Other included certain legal expenses unrelated to current or recent operations of approximately $7.0 million.

Restructuring_and_Other_Charge

Restructuring and Other Charges (Notes)	12 Months Ended
	Dec. 31, 2013
Restructuring and Related Activities [Abstract]	'
Restructuring and Other Charges	'
	Restructuring and Other Charges
	The following table presents restructuring and other charges included in cost of revenues and restructuring and other charges in the Consolidated Statements of Operations under the Company's restructuring plans (in millions):
		Years Ended December 31,
		2013		2012		2011
	Severance	$	22.9	$	36.7	$	15.3
	Facilities	10		5.8		0.2
	Contract terminations and other	14.6		57.2		15.1
	Total	$	47.5	$	99.7	$	30.6
	Reported as:
	Cost of revenues	$	8.4	$	52.9	$	—
	Restructuring and other charges	39.1		46.8		30.6
	Total	$	47.5	$	99.7	$	30.6
	Restructuring charges are based on the Company's restructuring plans that were committed to by management. Any changes in the estimates of executing the approved plans are reflected in the Company's results of operations.
	2013 Restructuring Plan
	During 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 $18.3 million in severance costs and $10.0 million of contract termination and project cancellation charges related to the 2013 Restructuring Plan during the year ended December 31, 2013. Under the 2013 Restructuring Plan, total costs incurred through December 31, 2013 were $28.3 million, of which $3.3 million was recorded within cost of revenues and $25.0 million was recorded within restructuring and other charges in the Consolidated Statements of Operations. In connection with the 2013 Restructuring Plan, the Company expects to record aggregate future charges of up to $2.0 million related to severance charges.
	2012 Restructuring Plan
	During 2012, the Company initiated a restructuring plan (the "2012 Restructuring Plan") to bring its cost structure more in line with its desired long-term financial and strategic model. The 2012 Restructuring Plan consists of workforce reductions, facility consolidations or closures, and supply chain and procurement efficiencies. During the year ended December 31, 2013, the Company continued to implement restructuring activities under the 2012 Restructuring Plan and recorded $19.3 million in charges for severance costs, facility consolidations or closures, and contract terminations. Under the 2012 Restructuring Plan, total costs incurred through December 31, 2013 were $112.6 million, of which $58.0 million was recorded within cost of revenues, primarily related to certain inventory and intangible asset impairment charges, and $54.6 million was recorded within restructuring and other charges in the Consolidated Statements of Operations. The restructuring activities related to this plan are substantially complete.
	2011 Restructuring Plan
	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 2013. As of December 31, 2013, the remaining restructuring liability under this plan relates to facility charges, which are expected to be completed by March 2018.
	Restructuring liabilities are reported within other accrued liabilities and other long-term liabilities on the Consolidated Balance Sheets. The following table provides a summary of changes in the restructuring liability related to the Company's plans as of December 31, 2013 (in millions):
		December 31,		Charges		Cash			Non-cash			December 31,
		2012				Payments			Settlements and			2013
									Other
	Severance	$	10.6	$	22.9	$	(27.8	)	$	(0.1	)	$	5.6
	Facilities	5.2		10		(6.0		)	(4.1		)	5.1
	Contract terminations and other	2.4		14.6		(9.3		)	(0.6		)	7.1
	Total	$	18.2	$	47.5	$	(43.1	)	$	(4.8	)	$	17.8

LongTerm_Debt_and_Financing_No

Long-Term Debt and Financing (Notes)	12 Months Ended
	Dec. 31, 2013
Debt Instruments [Abstract]	'
Long-Term Debt and Financing	'
	Long-Term Debt and Financing
	Long-Term Debt
	In March 2011, the Company issued $300.0 million aggregate principal amount of 3.10% senior notes due 2016 ("2016 Notes"), $300.0 million aggregate principal amount of 4.60% senior notes due 2021 ("2021 Notes"), and $400.0 million aggregate principal amount of 5.95% senior notes due 2041 ("2041 Notes" and, collectively the "Notes"). Interest on the Notes is payable in cash semiannually. The Company may redeem the Notes, at any time in whole or from time to time in part, subject to a make-whole premium, and, in the event of a change in control, the holders of the Notes may require the Company to repurchase for cash all or part of the Notes at a purchase price equal to 101% of the aggregate principle amount, plus accrued and unpaid interest, if any. The indenture that governs the Notes also contains various covenants, including limitations on the Company's ability to incur liens or enter into sale-leaseback transactions over certain dollar thresholds. As of December 31, 2013, the Company was in compliance with all of its debt covenants.
	The following table summarizes the Company's long-term debt (in millions, except percentages):
		As of December 31, 2013
		Amount			Effective Interest
					Rates
	Senior notes:
	3.10% fixed-rate notes, due 2016	$	300		3.12	%
	4.60% fixed-rate notes, due 2021	300			4.63	%
	5.95% fixed-rate notes, due 2041	400			6.01	%
	Total senior notes	1,000.00
	Unaccreted discount	(0.7		)
	Total	$	999.3
	The effective interest rates for the Notes include the interest, accretion of the discount, and amortization of issuance costs.
	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 $898.4 million, $677.8 million and $738.2 million during the years ended December 31, 2013, 2012, and 2011, respectively.
	The Company received cash proceeds from the financing provider of $843.9 million, $679.8 million, and $686.5 million during the years ended December 31, 2013, 2012, and 2011, respectively. As of December 31, 2013 and December 31, 2012, the amounts owed by the financing provider were $189.8 million and $147.6 million, respectively, and were recorded in accounts receivable on the Company’s Consolidated Balance Sheets.
	In 2013, 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 December 31, 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 $30.2 million as of December 31, 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 Consolidated Balance Sheets. As of December 31, 2013 and 2012, the estimated cash received from the financing provider not recognized as revenue from distributors was $62.3 million and $30.7 million, respectively.

Equity

Equity	12 Months Ended
	Dec. 31, 2013
Equity [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 and the $1.0 billion stock repurchase program approved by the Board in February 2010. As of December 31, 2013, there was $997.7 million 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 following table summarizes the Company's repurchases and retirements of its common stock under its stock repurchase programs and repurchases associated with minimum tax withholdings (in millions, except per share amounts):
		Shares			Average price				Amount
		Repurchased			per share				Repurchased
	2013
	Repurchases under stock repurchase programs	28.9			$	19.76			$	570.6
	Repurchases for tax withholding	0.4			$	20.23			$	7.2
	2012
	Repurchases under stock repurchase programs	35.8			$	18.05			$	645.6
	Repurchases for tax withholding	0.2			$	23.4			$	5
	2011
	Repurchases under stock repurchase programs	17.5			$	30.93			$	541.2
	Repurchases for tax withholding	0.2			$	35.98			$	7.4
	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. The Company's stock repurchase activity subsequent to 2013 was not material.
	Accumulated Other Comprehensive Income, Net of Tax
	The components of accumulated other comprehensive income, net of related taxes, as of December 31, 2013 and December 31, 2012 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, 2011	$	0.1			$	(10.9	)		$	(6.8	)	$	(17.6	)
	Other comprehensive gain before reclassifications	3.2				7.4				6.4			17
	Amount reclassified from accumulated other	(1.2		)		6.5				—			5.3
	comprehensive income
	Other comprehensive gain	2				13.9				6.4			22.3
	Balance as of December 31, 2012	$	2.1			$	3			$	(0.4	)	$	4.7
	Other comprehensive gain (loss) before reclassifications	65.1				0.7				(3.4		)	62.4
	Amount reclassified from accumulated other	(1.0		)		(1.5		)		—			(2.5		)
	comprehensive income
	Other comprehensive gain (loss)	64.1				(0.8		)		(3.4		)	59.9
	Balance as of December 31, 2013	$	66.2			$	2.2			$	(3.8	)	$	64.6
	________________________________
	(1)	The reclassifications out of accumulated other comprehensive income during the years ended December 31, 2013 and December 31, 2012 for realized gains on available-for-sale securities of $1.0 million and $1.2 million, respectively, are included in other expense, net, in the Consolidated Statements of Operations.
	(2)	The reclassifications out of accumulated other comprehensive income during the year ended December 31, 2013 for realized gains on cash flow hedges are included within cost of revenues of $1.1 million and sales and marketing of $4.3 million and for realized losses within research and development of $3.4 million and general and administrative of $0.5 million for which the hedged transactions relate in the Consolidated Statements of Operations. The reclassifications out of accumulated other comprehensive income during the year ended December 31, 2012 for realized losses on cash flow hedges are included within cost of revenues of $0.9 million, research and development of $2.3 million, sales and marketing of $2.0 million, and general and administrative of $1.3 million for which the hedged transactions relate in the Consolidated Statements of Operations.

Employee_Benefit_Plans_Notes

Employee Benefit Plans (Notes)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Employee Benefit Plans	'
	Employee Benefit Plans
	Equity Incentive Plans
	The Company’s equity incentive 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").
	As of December 31, 2013, a total of approximately 103.8 million shares of common stock were reserved for future issuance upon exercise of stock options and vesting of RSUs, RSAs, and PSAs, and for the future grant of share-based compensation awards under the Company's equity incentive plans.
	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 December 31, 2013, the 2006 Plan had 43.8 million shares subject to currently outstanding equity awards and 49.1 million shares available for future issuance. Options granted under the 2006 Plan have a maximum term of seven years from the date of grant, and generally vest and become exercisable over a four-year period. Subject to the terms of change of control severance agreements, and except for a limited number of shares allowed under the 2006 Plan, RSUs or PSAs that vest solely based on continuing employment or provision of services will vest in full no earlier than three years from the grant date, or in the event vesting is based on factors other than continued future provision of services, such awards will vest in full no earlier than one year from the grant date.
	During the year ended December 31, 2012, the Company completed the acquisitions of Mykonos and Contrail and assumed their respective plans: Mykonos Software, Inc. 2010 Stock Plan and Contrail Systems Inc. 2012 Stock Plan. In connection with these plans, the Company assumed stock options, RSUs, and RSAs and exchanged the assumed awards for Juniper Networks' stock options, RSUs, and RSAs, respectively. No additional awards can be granted under these plans. The Company assumed an aggregate of 7.0 million shares of stock options, RSUs, and RSAs in connection with the acquisitions of Mykonos and Contrail, of which 5.8 million shares were exempt from registration under the Securities Act of 1933, as amended (the “Securities Act”), in reliance upon Section 4(2) of the Securities Act as transactions by an issuer not involving any public offering and/or the private offering safe harbor provision of Rule 506 of Regulation D promulgated under the Securities Act. As of December 31, 2013 stock options, RSUs, and RSAs representing approximately 4.7 million shares of common stock were outstanding under all awards assumed through the Company's acquisitions.
	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 the ESPP. 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 December 31, 2013, approximately 12.8 million shares have been issued and 6.2 million shares remain available for future issuance under the ESPP.
	Stock Option Activities
	Since 2006, the Company has granted stock option awards that have a maximum contractual life of seven years from the date of grant. Prior to 2006, stock option awards generally had a ten-year contractual life from the date of grant.
	The following table summarizes the Company’s stock option activity and related information as of and for the three years ended December 31, 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, 2010	49.4			$	21.9			4.1		$	744.5
	Granted	5.6			37.17
	Canceled	(1.9	)		26.76
	Exercised	(13.9	)		21.13
	Expired	(0.6	)		34.32
	Balance as of December 31, 2011	38.6			$	23.98			3.7		$	75.3
	Granted	3.1			22.81
	Assumed(*)	0.9			0.57
	Canceled	(2.8	)		26.64
	Exercised	(3.6	)		11.71
	Expired	(2.1	)		26.97
	Balance as of December 31, 2012	34.1			$	24.13			3.1		$	52.5
	Granted	—			—
	Canceled	(1.3	)		29.56
	Exercised	(5.6	)		15.58
	Expired	(4.1	)		28.35
	Balance as of December 31, 2013	23.1			$	25.15			2.4		$	44.6
	As of December 31, 2013:
	Vested and expected-to-vest options	22.8			$	25.24			2.4		$	42
	Exercisable options	20.5			$	25.4			2		$	30
	_____________________________
	(*)	Stock options assumed in connection with the acquisition of Contrail.
	Aggregate intrinsic value represents the difference between the Company’s closing stock price on the last trading day of the period, which was $22.57 per share as of December 31, 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 the exercise and the exercise price of each option, was $29.4 million, $27.9 million, and $249.8 million for 2013, 2012, and 2011, respectively. Total fair value of options vested during 2013, 2012, and 2011 was $45.2 million, $70.9 million, and $80.7 million, respectively.
	The following table summarizes additional information regarding outstanding and exercisable options as of December 31, 2013:
			Options Outstanding									Options Exercisable
	Range of Exercise Price		Number Outstanding			Weighted Average		Weighted Average				Number	Weighted Average
	(In dollars)		(In millions)			Remaining		Exercise Price				Exercisable	Exercise Price
						Contractual Life		(In dollars)				(In millions)	(In dollars)
						(In years)
	$0.03 - $15.09		2.9			3.9		$	10.89			2.3	$	13.76
	$16.00 - $21.12		2.4			1.4		18.41				2.3	18.33
	$21.43 - $23.84		2.4			2.2		22.46				2.1	22.6
	$23.89 - $24.20		2.6			2.3		24.16				2.1	24.15
	$24.25 - $25.49		2.3			1.3		25.07				2.3	25.07
	$25.50 - $26.90		3.2			1.8		26.55				3.2	26.55
	$26.97 - $29.89		3.1			2.6		28.54				2.9	28.52
	$29.93 - $38.93		2.2			2.2		33.31				1.9	33.16
	$40.26 - $40.26		1.1			4		40.26				0.8	40.26
	$44.00 - $44.00		0.9			4.1		44				0.6	44
	$0.03 - $44.00		23.1			2.4		$	25.15			20.5	$	25.4
	Restricted Stock Unit, Restricted Stock Award, and Performance Share Award Activities
	RSUs and RSAs generally vest over a period of three to four years from the date of grant and PSAs generally vest after three years provided that certain annual performance targets and other vesting criteria are met. Until vested, RSUs and PSAs do not have the voting and dividend participation rights of common stock and the shares underlying the awards are not considered issued and outstanding.
	The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the three years ended December 31, 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, 2010	14.2			$	25.94			1.7		$	522.9
RSUs granted	7.3			31.75
PSAs granted(1)	4.5			38.64
RSUs vested(6)	(1.7	)		23.26
PSAs vested(6)	(0.8	)		24.76
RSUs canceled	(1.0	)		31.57
PSAs canceled	(2.9	)		30.72
Balance as of December 31, 2011	19.6			$	30.27			1.5		$	400.5
RSUs granted	9.9			20.79
RSUs assumed(3)(4)	0.2			22.21
PSAs granted(2)	2.2			23.07
RSAs assumed(4)	5.8			19.59
RSUs vested(6)	(3.1	)		27.04
PSAs vested(6)	(1.9	)		18.21
RSAs vested(6)	(0.7	)		19.59
RSUs canceled	(2.9	)		27.77
PSAs canceled	(2.3	)		29.71
Balance as of December 31, 2012	26.8			$	27.76			1.7		$	565
RSUs granted	10.3			20.32
PSAs granted(5)	2.2			21.27
RSUs vested(6)	(6.1	)		26.15
PSAs vested(6)	(1.1	)		28.52
RSAs vested(6)	(1.6	)		19.59
RSUs canceled	(3.4	)		22.99
PSAs canceled	(1.7	)		29.1
Balance at December 31, 2013	25.4			$	23.44			1.1		$	573.5
As of December 31, 2013:
Vested and expected-to-vest RSUs, RSAs	20.8			$	23.77			1		$	469.2
and PSAs
________________________________
(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 is estimated at 1.9 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 4.5 million shares.
(2)	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 0.9 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.
(3)	RSUs assumed in connection with the acquisition of Mykonos.
(4)	RSUs and RSAs assumed in connection with the acquisition of Contrail.
-5	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.
-6	Total fair value of RSUs, RSAs, and PSAs vested during 2013, 2012, and 2011 was $221.5 million, $132.0 million, and $57.7 million, respectively.
Shares Available for Grant
The following table presents the stock activity and the total number of shares available for grant under the 2006 Plan as of December 31, 2013 (in millions):
	Number of Shares
Balance as of December 31, 2012	57.3
RSUs and PSAs granted (1)	(26.1	)
RSUs and PSAs canceled (1)	12.6
Options canceled (2)	1.2
Options expired (2)	4.1
Balance as of December 31, 2013	49.1
________________________________
(1)	RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant under the 2006 Plan are counted against shares authorized under the plan as two and one-tenth shares of common stock for each share subject to such award. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term.
(2)	Includes canceled or expired options under the 1996 Plan and the 2000 Plan that expired after May 18, 2006, which become available for grant under the 2006 Plan according to its terms.
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 3.3 million, 3.5 million, and 2.4 million shares of common stock through the ESPP at an average exercise price of $16.53, $16.26, and $21.53 per share during 2013, 2012, and 2011, respectively.
Valuation Assumptions
The weighted-average assumptions used and the resulting estimates of fair value for stock options and ESPP were as follows:
	Years Ended December 31,
	2013		2012		2011
Stock Options:
Volatility	—		45%		43%
Risk-free interest rate	—		0.70%		1.50%
Expected life (years)	0 years		4.2		4.1
Dividend yield	—		—		—
Weighted-average fair value per share	—		$8.47		$13.17
ESPP:
Volatility	36%		47%		41%
Risk-free interest rate	0.10%		0.10%		0.20%
Expected life (years)	0.5		0.5		0.5
Dividend yield	—		—		—
Weighted-average fair value per share	$5.54		$5.53		$7.48
Share-Based Compensation Expense
Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and ESPP was recorded in the following cost and expense categories in the Company's Consolidated Statements of Operations (in millions):
	Years Ended December 31,
	2013				2012				2011
Cost of revenues - Product	$	4.7			$	4.6			$	4.6
Cost of revenues - Service	15.4				17				15.7
Research and development	127.6				109.1				97.7
Sales and marketing	70.9				81.6				70.9
General and administrative	26				31.1				33.3
Total	$	244.6			$	243.4			$	222.2
The following table summarizes share-based compensation expense by award type (in millions):
	Years Ended December 31,
	2013				2012				2011
Stock options	$	31.5			$	58.9			$	76.2
RSUs, RSAs, and PSAs	196.8				163.7				127.5
ESPP	16.3				20.8				18.5
Total	$	244.6			$	243.4			$	222.2
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 December 31, 2013 (in millions, except years):
	Unrecognized				Weighted Average
	Compensation Cost				Period
					(In Years)
Stock options	$	33.6			1.8
RSUs, RSAs, and PSAs	$	279.1			1.8
401(k) Plan
The Company maintains a savings and retirement plan qualified under Section 401(k) of the Internal Revenue Code of 1986, as amended (the "IRC"). Employees meeting the eligibility requirements, as defined under the IRC, may contribute up to the statutory limits each year. The Company currently matches 30% of all eligible employee contributions which vest immediately. The Company’s matching contributions to the plan totaled $20.7 million, $20.2 million, and $16.3 million during the years ended December 31, 2013, 2012, and 2011, respectively.
Deferred Compensation Plan
The Company’s non-qualified deferred compensation (“NQDC”) plan is an unfunded and unsecured deferred compensation arrangement. Under the NQDC plan, officers and other senior employees may elect to defer a portion of their compensation and contribute such amounts to one or more investment funds. The NQDC plan assets are included within short-term investments and offsetting obligations are included within accrued compensation in the Consolidated Balance Sheets. The investments are considered trading securities and are reported at fair value. The realized and unrealized holding gains and losses related to these investments are recorded in other expense, net, and the offsetting compensation expense is recorded as operating expenses in the Consolidated Statements of Operations. The deferred compensation liability under the NQDC plan was approximately $15.4 million and $12.6 million as of December 31, 2013 and December 31, 2012, respectively.

Segments_Notes

Segments (Notes)	12 Months Ended
	Dec. 31, 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. During 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. In addition, the Company realigned its Contrail products from the PSD segment to the SSD segment. The Company reclassified the segment data for the prior years to conform to the current year 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 the QFabric™ system.
	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 fiscal 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):
		Years Ended December 31,
		2013			2012			2011
	PSD product revenues:
	Routing	$	2,243.60		$	1,946.80		$	2,166.10
	Switching	638			554.8			495.8
	Total PSD product revenues	2,881.60			2,501.60			2,661.90
	PSD service revenues	796.6			769.2			645
	Total PSD revenues	3,678.20			3,270.80			3,306.90
	SSD product revenues:
	Security	564.3			669.9			698.3
	Routing	74			90.6			118.1
	Total SSD product revenues	638.3			760.5			816.4
	SSD service revenues	352.6			334.1			325.4
	Total SSD revenues	990.9			1,094.60			1,141.80
	Total net revenues	$	4,669.10		$	4,365.40		$	4,448.70
	Segment contribution margin:
	PSD	$	1,621.00		$	1,276.40		$	1,426.80
	SSD	398.4			473.6			504.4
	Total segment contribution margin	2,019.40			1,750.00			1,931.20
	Corporate unallocated expenses (1)	(1,123.5		)	(1,068.7		)	(1,013.9		)
	Amortization of purchased intangible assets (2)	(31.9		)	(32.3		)	(27.1		)
	Share-based compensation expense	(244.6		)	(243.4		)	(222.2		)
	Share-based payroll tax expense	(5.1		)	(1.1		)	(9.3		)
	Restructuring and other charges (3)	(47.5		)	(99.7		)	(30.6		)
	Acquisition-related charges (4)	(0.9		)	(2.0		)	(9.6		)
	Other unallocated expense	—			5.3			—
	Total operating income	565.9			308.1			618.5
	Other expense, net	(40.4		)	(16.6		)	(46.8		)
	Income before income taxes and noncontrolling interest	$	525.5		$	291.5		$	571.7
	________________________________
	(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.
	(4)	Amount includes acquisition-related costs reported in cost of revenues and operating expenses.
	Depreciation expense allocated to the PSD segment was $117.3 million, $116.9 million, and $104.9 million for the years ended December 31, 2013, 2012, and 2011, respectively. The depreciation expense allocated to the SSD segment was $30.9 million, $37.8 million, and $37.3 million for the years ended December 31, 2013, 2012, and 2011, 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):
		Years Ended December 31,
		2013			2012			2011
	Americas:
	United States	$	2,381.50		$	2,067.50		$	2,015.80
	Other	232			218.4			222.2
	Total Americas	2,613.50			2,285.90			2,238.00
	Europe, Middle East, and Africa	1,256.90			1,266.30			1,339.80
	Asia Pacific	798.7			813.2			870.9
	Total	$	4,669.10		$	4,365.40		$	4,448.70
	During the years ended December 31, 2013 and 2011, no customer accounted for greater than 10% of the Company's net revenues. During the year ended December 31, 2012, Verizon accounted for 10.3% of the Company's net revenues across both of its segments.
	The following table presents geographic information for property and equipment, net (in millions):
		As of December 31,
		2013			2012
	United States	$	801.3		$	725.5
	International	81			86.4
	Property and equipment, net	$	882.3		$	811.9
	The Company tracks assets by physical location. The majority of the Company’s assets, excluding cash and cash equivalents and investments, as of December 31, 2013 and December 31, 2012, were attributable to U.S. operations. 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)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The components of income before the provision for income taxes and noncontrolling interest are summarized as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Domestic	$	248.7		$	114.1		$	218.4
	Foreign	276.8			177.4			353.3
	Total income before provision for income taxes and	$	525.5		$	291.5		$	571.7
	noncontrolling interest
	The provision for income taxes is summarized as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Current provision:
	Federal	$	(12.9	)	$	94.3		$	19.5
	States	(5.0		)	8.4			0.9
	Foreign	32.5			37.1			47.8
	Total current provision	14.6			139.8			68.2
	Deferred provision (benefit):
	Federal	51.2			(28.8		)	23
	States	(2.7		)	(1.5		)	0.6
	Foreign	22.6			3.5			(3.6		)
	Total deferred provision (benefit)	71.1			(26.8		)	20
	Income tax benefits attributable to employee stock plan activity	—			(8.0		)	58.5
	Total provision for income taxes	$	85.7		$	105		$	146.7
	The provision for income taxes differs from the amount computed by applying the federal statutory rate to income before provision for income taxes as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Expected provision at 35% rate	$	184		$	102		$	200.1
	State taxes (benefit), net of federal benefit	(3.6		)	2			2
	Foreign income at different tax rates	(37.7		)	(11.6		)	(50.4		)
	Research and development credits	(32.5		)	(0.5		)	(21.3		)
	Share-based compensation	25.6			22.4			16.7
	Settlement with tax authorities	(28.3		)	—			—
	Domestic production activities	(26.3		)	—			—
	Equity investment gain on acquisition	—			(5.3		)	—
	Other	4.5			(4.0		)	(0.4		)
	Total provision for income taxes	$	85.7		$	105		$	146.7
	In 2013, the Company recorded $64.2 million of net income tax benefit related to items unique to the year. These amounts included $19.7 million for a multi-year claim related to the U.S. production activities deduction, $28.3 million for a tax settlement with the Internal Revenue Service (“IRS”), and $16.2 million of U.S. federal R&D tax credit resulting from the American Taxpayer Relief Act of 2012 signed on January 2, 2013, which retroactively reinstated the U.S. federal R&D tax credit from January 1, 2012 to December 31, 2013.
	Deferred income taxes reflect the net tax effects of tax carry-forward items and temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company's deferred tax assets and liabilities are as follows (in millions):
		As of December 31,
		2013			2012
	Deferred tax assets:
	Net operating loss carry-forwards	$	1.1		$	10
	Foreign tax credit carry-forwards	63.4			58
	Research and other credit carry-forwards	106.6			95.3
	Deferred revenue	71			98.6
	Stock-based compensation	86.1			97.5
	Reserves and accruals not currently deductible	153.9			175.2
	Other	13.7			13.6
	Total deferred tax assets	495.8			548.2
	Valuation allowance	(155.7		)	(141.0		)
	Deferred tax assets, net of valuation allowance	340.1			407.2
	Deferred tax liabilities:
	Property and equipment basis differences	(3.1		)	(1.0		)
	Purchased intangibles	(10.1		)	(40.8		)
	Unremitted foreign earnings	(258.9		)	(229.1		)
	Deferred compensation and other	(38.7		)	—
	Other	(0.4		)	(1.2		)
	Total deferred tax liabilities	(311.2		)	(272.1		)
	Net deferred tax assets	$	28.9		$	135.1
	The breakdown between current and long-term deferred tax assets and deferred tax liabilities are as follows (in millions):
		As of December 31,
		2013			2012
	Current deferred tax assets	$	79.8		$	172.6
Current deferred tax liabilities	—			—
Long-term deferred tax assets	2.4			—
Long-term deferred tax liabilities	(53.3		)	(37.5		)
Total net deferred tax assets	$	28.9		$	135.1
As of December 31, 2013, and 2012, the Company had a valuation allowance on its U.S. domestic deferred tax assets of approximately $155.7 million and $141.0 million, respectively. The balance at December 31, 2013 consisted of approximately $109.2 million and $9.7 million against the Company's California and Massachusetts deferred tax assets, respectively, which the Company believes are not more likely than not to be utilized in future years. The remaining deferred tax assets on which the Company recorded a valuation allowance are approximately $36.8 million related to losses that are capital in nature and may carry forward to offset future capital gains only. The valuation allowance increased $14.7 million in 2013 related to the increase in the California research and development credit and decreased $4.2 million in 2012 related to the utilization of losses that are capital in nature.
As of December 31, 2013, the Company had federal and California net operating loss carry-forwards of approximately $1.2 million and $40.6 million, respectively. The Company also had California tax credit carry-forwards of approximately $208.1 million. Approximately $20.1 million of the benefit from the California tax credit carry-forwards will be credited to additional paid-in capital when realized on the Company's income tax returns. Unused net operating loss carry-forwards will expire at various dates beginning in the year 2014. The California tax credit carry-forwards will carry forward indefinitely.
The Company provides U.S. income taxes on the earnings of foreign subsidiaries unless the subsidiaries' earnings are considered indefinitely reinvested outside of the United States. The Company has made no provision for U.S. income taxes on approximately $1.5 billion of cumulative undistributed earnings of certain foreign subsidiaries through December 31, 2013. These earnings are considered indefinitely invested in operations outside of the U.S., as the Company intends to utilize these amounts to fund future expansion of its international operations. If these earnings were distributed to the United States in the form of dividends or otherwise, or if the shares of the relevant foreign subsidiaries were sold or otherwise transferred, the Company would be subject to additional U.S. income taxes (subject to an adjustment for foreign tax credits) and foreign withholding taxes. Determination of the amount of unrecognized deferred income tax liability related to these earnings is not practicable.
As of December 31, 2013, 2012, and 2011 the total amount of gross unrecognized tax benefits was $137.6 million, $136.1 million, and $132.2 million, respectively. As of December 31, 2013, approximately $128.8 million of the $137.6 million gross unrecognized tax benefits, if recognized, would affect the effective tax rate.
A reconciliation of the beginning and ending amount of the Company's total gross unrecognized tax benefits was as follows (in millions):
	Years Ended December 31,
	2013			2012			2011
Balance at beginning of year	$	136.1		$	132.2		$	116.4
Tax positions related to current year:
Additions	15.8			8.8			17.6
Tax positions related to prior years:
Additions	22.6			0.9			6.4
Reductions	(2.2		)	—			—
Settlements	(31.1		)	(1.2		)	(5.4		)
Lapses in statutes of limitations	(3.6		)	(4.6		)	(2.8		)
Balance at end of year	$	137.6		$	136.1		$	132.2
As of December 31, 2013, 2012, and 2011 the Company had accrued interest and penalties related to unrecognized tax benefits of $18.4 million, $16.7 million, and $17.3 million, respectively, within other long-term liabilities in the Consolidated Balance Sheets. The Company recognized an expense for net interest and penalties of $0.6 million and a benefit of $0.6 million and $1.6 million in its Consolidated Statements of Operations during the years ended December 31, 2013, 2012, and 2011, respectively.
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 $1.6 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.
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.
During the fourth quarter of 2011, the Company resolved an audit by a state tax authority for the years from 2002 through 2004. As a result of the settlement, the Company recorded a tax benefit or approximately $7.0 million including interest and penalties.
The Company conducts business globally and, as a result, Juniper Networks or one or more of its subsidiaries files income tax returns in the U.S. federal jurisdiction and various state and foreign jurisdictions. In the normal course of business the Company is subject to examination by taxing authorities throughout the world, including such major jurisdictions as the Netherlands, U.K., France, Germany, Japan, China, Australia, India, and the U.S. With few exceptions, the Company is no longer subject to U.S. federal, state and local, and non-U.S. income tax examinations for years before 2004.
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 2008 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 December 31, 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.

Net_Income_per_Share_Notes

Net Income per Share (Notes)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Net Income Per Share	'
	Net Income per Share
	The Company computed basic and diluted net income per share attributable to Juniper Networks common stockholders as follows (in millions, except per share amounts):
		Years Ended December 31,
		2013		2012		2011
	Numerator:
	Net income attributable to Juniper Networks	$	439.8	$	186.5	$	425.1
	Denominator:
	Weighted-average shares used to compute basic net income per share	501.8		520.9		529.8
	Dilutive effect of employee stock awards	8.5		5.3		11.6
	Weighted-average shares used to compute diluted net income	510.3		526.2		541.4
	per share
	Net income per share attributable to Juniper Networks common
	stockholders:
	Basic	$	0.88	$	0.36	$	0.8
	Diluted	$	0.86	$	0.35	$	0.79
	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 13.2 million, 32.3 million, and 17.4 million shares for the years ended December 31, 2013, 2012, and 2011, respectively, were excluded from the computation of diluted net income because their effect would be anti-dilutive.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Operating Leases
	The following table summarizes the Company’s future minimum payments under non-cancelable operating leases for each of the next five years and thereafter as of December 31, 2013 (in millions):
	Years Ending December 31,	Amount
	2014	$	49.4
	2015	38.4
	2016	31.1
	2017	26.8
	2018	22.6
	Thereafter	56.9
	Total	$	225.2
	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. Rent expense for 2013, 2012, and 2011 was approximately $52.8 million, $63.2 million, and $65.7 million, respectively.
	Purchase Commitments with Contract Manufacturers and Suppliers
	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 $491.4 million as of December 31, 2013.
	The Company establishes a liability in connection with purchase commitments related to quantities in excess of its demand forecasts or obsolete materials charges for components purchased by the contract manufacturers based on the Company’s demand forecast or customer orders. As of December 31, 2013, the Company had accrued $22.9 million based on its estimate of such charges.
	Long-Term Debt and Interest Payment on Long-Term Debt
	As of December 31, 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 December 31, 2013, other contractual obligations primarily consisted of $89.5 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 $13.1 million, and $10.3 million of agreements that are firm, non-cancelable and specify terms, including: fixed or minimum quantities to be purchased; fixed, minimum or variable price provisions; and the approximate timing of payment.
	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 December 31, 2013 and December 31, 2012, the Company had $40.1 million and $12.6 million, respectively, in financing arrangements, bank guarantees, and standby letters of credit related to these financial guarantees, of which $30.2 million in financing guarantees was recorded in other accrued liabilities and other long-term liabilities in the Consolidated Balance Sheets as of December 31, 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 alleged that the defendants made false and misleading statements regarding the Company's revenues, business practices, and internal controls. The complaint purported 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 sought an unspecified amount of monetary damages on behalf of the purported class. On November 12, 2013, the court issued an order appointing Warren Avery as lead plaintiff. On January 9, 2014, lead plaintiff filed a notice of voluntary dismissal of the action without prejudice. On January, 23, 2014, the court entered an order of dismissal without prejudice.
	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 is now Case No. 13-cv-04829-WHO. 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. On January 22, 2014, the Company filed a motion to dismiss the action. A hearing on the motion is scheduled for April 23, 2014.
	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.

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited) (Notes)	12 Months Ended
	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]	'
Selected Quarterly Financial Data (Unaudited)	'
	Selected Quarterly Financial Data (Unaudited)
	The tables below set forth selected unaudited financial data for each quarter of the two years ended December 31, 2013 (in millions, except per share amounts):
	Year Ended December 31, 2013		First Quarter			Second Quarter			Third Quarter			Fourth Quarter
	Net revenues:
	Product		$	781.8		$	863.8		$	900.8		$	973.5
	Service		277.4			286.9			284.8			300.1
	Total net revenues		1,059.20			1,150.70			1,185.60			1,273.60
	Cost of revenues:
	Product		278.2			321.3			325.5			351.6
	Service		110.2			108.9			113.6			118.4
	Total cost of revenues (2)		388.4			430.2			439.1			470
	Gross margin		670.8			720.5			746.5			803.6
	Operating expenses:
	Research and development(1)		262.2			257.7			264.6			258.7
	Sales and marketing(4)		256.1			267.1			269.5			283.2
	General and administrative(4)		58.5			49.2			61.4			48.2
	Restructuring and other charges(2)		7			8			6			18.1
	Total operating expenses		583.8			582			601.5			608.2
	Operating income		87			138.5			145			195.4
	Other expense, net		(10.1		)	(12.6		)	(7.5		)	(10.2		)
	Income before income taxes		76.9			125.9			137.5			185.2
	Income tax (benefit) provision		(14.1		)	28			38.4			33.4
	Net income		$	91		$	97.9		$	99.1		$	151.8
	Net income per share:(3)
	Basic		$	0.18		$	0.19		$	0.2		$	0.3
	Diluted		$	0.18		$	0.19		$	0.19		$	0.3
	_______________________________
	(1)	In the second quarter of 2013, the Company extended the useful lives of certain computers and equipment based on 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. This change in accounting estimate decreased depreciation expense within research and development expense by approximately $11.0 million or $0.01 per diluted share for the second quarter of 2013, $9.4 million or $0.01 for the third quarter of 2013, and $7.9 million or $0.01 for the fourth quarter of 2013.
	(2)	In the third quarter of 2013, the Company implemented the 2013 Restructuring Plan for workforce reductions, contract terminations, and project cancellations and recorded restructuring charges of $7.4 million and $3.7 million to operating expenses and cost of revenues, respectively. In the fourth quarter of 2013, the Company continued to implement restructuring activities under the 2013 Restructuring Plan and primarily recorded charges to operating expenses of $17.6 million.
	(3)	Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.
	(4)	Certain amounts in the prior quarters' Condensed Consolidated Statements of Operations have been reclassified to conform to the current year presentation.
	Year Ended December 31, 2012		First Quarter			Second Quarter			Third Quarter(1)			Fourth Quarter
	Net revenues:
	Product		$	771.9		$	804.7		$	838.2		$	847.3
	Service		260.6			269.1			280.1			293.5
	Total net revenues		1,032.50			1,073.80			1,118.30			1,140.80
	Cost of revenues:
	Product		280.6			292.6			334.7			296.1
	Service		117.8			113.3			109.8			111.7
	Total cost of revenues(2)		398.4			405.9			444.5			407.8
	Gross margin		634.1			667.9			673.8			733
	Operating expenses:
	Research and development		269.6			268.7			288.2			275.1
	Sales and marketing(4)		258.6			260.4			261.8			264.7
	General and administrative(4)		56.2			48.9			50			51.7
	Restructuring and other charges(2)		2			3.2			31			10.6
	Total operating expenses		586.4			581.2			631			602.1
	Operating income		47.7			86.7			42.8			130.9
	Other (expense) income, net		(24.4		)	2.8			(4.0		)	9
	Income before income taxes		23.3			89.5			38.8			139.9
	Income tax provision		7			31.8			22			44.2
	Net income		$	16.3		$	57.7		$	16.8		$	95.7
	Net income per share(3)
	Basic		$	0.03		$	0.11		$	0.03		$	0.19
	Diluted		$	0.03		$	0.11		$	0.03		$	0.19
	_______________________________
	-1	During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.
	-2	In the third quarter of 2012, the Company implemented the 2012 Restructuring Plan for workforce reductions, facility consolidations or closures, and supply chain and procurement efficiencies and recorded restructuring charges of $29.5 million. In connection with its restructuring activities, the Company also recorded certain inventory and intangible asset impairment charges totaling $52.4 million to cost of revenues. In the fourth quarter of 2012, the Company continued to implement restructuring activities under the 2012 Restructuring Plan.
	(3)	Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.
	(4)	Certain amounts in the prior quarters' Condensed Consolidated Statements of Operations have been reclassified to conform to the current year presentation.

Subsequent_Events_Notes

Subsequent Events (Notes)	12 Months Ended
	Dec. 31, 2013
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	Integrated Operating Plan
	In February 2014, the Company announced an integrated operating plan ("IOP") focused on innovation that matters most to service providers and enterprises where demand for High-IQ Networks and best-in-class cloud environments are driving growth. Through the execution of the IOP the Company will coalesce its engineering talent, go-to-market teams and R&D around this strategy resulting in streamlined operations and business portfolio and operational efficiencies.
	The Company expects to initiate a substantial cost reduction plan in connection with the IOP accomplished through various restructuring activities. The Company is not able to make a reasonable estimate of future restructuring costs associated with the IOP.
	As part of the IOP, the Company announced a commitment to return a minimum of $3.0 billion to shareholders over the next three years through a combination of share repurchases and dividends. As part of this plan, the Board of Directors has authorized $2.0 billion in share repurchases to be executed through the end of the first quarter of 2015, including $1.2 billion through an accelerated share repurchase program to be entered into during the first quarter of 2014. The Company will also initiate a quarterly cash dividend of $0.10 per share of common stock beginning in the third quarter of 2014. These activities will be funded by a combination of existing cash balances and debt offerings.
	Business Combination
	Subsequent to December 31, 2013, the Company acquired WANDL, Inc. (“WANDL”), a provider of software solutions for advanced planning, management, design and optimization of next-generation multi-layer networks for cash and stock consideration of approximately $30.0 million. This acquisition provides the Company with technology and experience in traffic engineering, multi-layer optimization and path computation, to help service provider customers optimize the performance and cost of their networks. The initial purchase accounting for this transaction was not yet complete at the filing of this Report.

Schedule_II_Valuation_and_Qual

Schedule II- Valuation and Qualifying Account	12 Months Ended
	Dec. 31, 2013
Valuation and Qualifying Accounts [Abstract]	'
Schedule II - Valuation and Qualifying Account	'
	Allowance for Doubtful Accounts	Balance at		Charged to			Write-offs,			Balance at
		Beginning of		(Reversed from)			Net of			End of
		Year		Costs and			Recoveries			Year
				Expenses
	2013	$	9.5	$	(3.8	)	$	(0.3	)	$	5.4
	2012	$	9.5	$	0.1		$	(0.1	)	$	9.5
	2011	$	10.1	$	(0.2	)	$	(0.4	)	$	9.5
				Additions
	Sales Return Reserve	Balance at		Charged as a			Charged to			Used			Balance at
		Beginning of		Reduction in			Other Accounts						End of
		Year		Revenues									Year
	2013	$	52.7	$	35		$	61.5		$	(100.2	)	$	49
	2012	$	52	$	40		$	48.6		$	(87.9	)	$	52.7
	2011	$	52.8	$	44.9		$	64.6		$	(110.3	)	$	52

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Cash and Cash Equivalents, Policy	'
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash on hand, demand deposits with banks, highly liquid investments in money market funds, commercial paper, government securities, certificates of deposit, and corporate debt securities, which are readily convertible into cash. All highly liquid investments purchased with original maturities of three months or less are classified as cash and cash equivalents.
Investments in Available-for-Sale and Trading Securities, Policy	'
	Investments in Available-for-Sale and Trading Securities
	The Company's investments in publicly-traded debt and equity securities are classified as available-for-sale. Available-for-sale investments are initially recorded at cost and periodically adjusted to fair value in the Consolidated Balance Sheets. Unrealized gains and losses on these investments are reported as a separate component of accumulated other comprehensive income. Realized gains and losses are determined based on the specific identification method and are reported in the Consolidated Statements of Operations.
	The Company periodically evaluates its investments to determine if impairment charges are required. The Company considers various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value has been less than the Company's cost basis, the investment's financial condition, and near-term prospects of the investee. If the Company determines that the decline in an investment's fair value is other than temporary, the difference is recognized as an impairment loss in its Consolidated Statements of Operations.
	The Company's non-qualified compensation plan is invested in mutual funds which are classified as trading securities and reported at fair value in the Consolidated Balance Sheets. The realized and unrealized holding gains and losses are reported in the Consolidated Statements of Operations.
Privately-Held Investments, Policy	'
	Privately-Held Investments
	The Company has privately-held investments, which are included in other long-term assets in the Consolidated Balance Sheets. These investments are carried at cost, adjusted for any impairment, as the Company does not have a controlling interest and does not have the ability to exercise significant influence over these companies. These investments are inherently high risk as the market for technologies or products manufactured by these companies are usually in their early stages at the time of the investment by the Company and such markets may never be significant. The Company measures the fair value of privately-held investments using an analysis of the financial conditions and near term prospects of the investees, including recent financing activities and their capital structure. Realized gains and losses, if any, are reported in the Consolidated Statements of Operations.
Fair Value, Policy	'
	Fair Value
	Fair value is defined as the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which it transacts, and considers assumptions that market participants would use when pricing the asset or liability. The Company applies the following fair value hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:
	Level 1 – Quoted prices in active markets for identical assets or liabilities.
	Level 2 – Quoted prices for similar assets and liabilities in active markets or inputs that are observable for the asset or liability, either directly or indirectly through market corroboration, for substantially the full term of the financial instrument. These inputs are valued using market based approaches.
	Level 3 – Inputs are unobservable inputs based on the Company’s assumptions. These inputs, if any, are valued using internal financial models.
Derivatives, Policy	'
	Derivatives
	The Company uses derivatives to partially offset its market exposure to fluctuations in certain foreign currencies. The Company does not enter into derivatives for speculative or trading purposes.
	The Company uses foreign currency forward or option contracts to hedge certain forecasted foreign currency transactions relating to operating expenses. 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. These derivatives are carried at fair value and 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 costs 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, on its 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.
	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 Consolidated Statements of Operations. Changes in the fair value of these derivatives are largely offset by remeasurement of the underlying assets and liabilities. Cash flows from such derivatives are classified as operating activities. These foreign exchange forward contracts have maturities of one year or less.
Inventory, Policy	'
	Inventory
	Inventory consists primarily of component parts to be used in the manufacturing process and is stated at the lower of cost or market. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. A charge is recorded to cost of product when inventory is determined to be in excess of anticipated demand or considered obsolete. The point of loss recognition, a new, lower-cost basis for that inventory is established, and subsequent changes in facts and circumstances do not result in the restoration or increase in the newly established cost basis.
Property and Equipment, Policy	'
	Property and Equipment
	Property and equipment are recorded at cost less accumulated depreciation. Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets:
		Estimated Useful Life (years)
	Computers, equipment, and software	3 to 5
	Furniture and fixtures	5
	Building and building improvements	7 to 40
	Land improvements	10 to 40
	Leasehold improvements	Lease term, not to exceed 10 years
	Construction in progress is related to the construction or development of property and equipment that have not yet been placed in service for their intended use. Depreciation for equipment commences once it is placed in service and depreciation for buildings and leasehold improvements commences once they are ready for their intended use.
	Effective April 1, 2013, the Company extended the useful lives of certain computers and equipment based on 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. During the year ended December 31, 2013, this change in accounting estimate decreased depreciation expense by approximately $28.3 million or $0.04 per diluted share.
Goodwill and Other Long-Lived Assets, Policy	'
	Goodwill and Other Long-Lived Assets
	Goodwill represents the future economic benefits arising from other assets acquired in a business combination or an acquisition that are not individually identified and separately recorded. The excess of the purchase price over the estimated fair value of net assets of businesses acquired in a business combination is recognized as goodwill. Goodwill is tested for impairment annually during the fourth quarter or more frequently if certain indicators are present. Other intangible assets acquired in a business combination and determined to have an indefinite useful life are not amortized but are assessed for potential impairment annually or when events or circumstances indicate that their carrying amounts might be impaired.
	The Company performs its annual goodwill impairment analysis at its reporting unit level, which may be one level below its operating segment level during the fourth quarter of each year or more frequently if certain indicators are present. The fair value of the Company's reporting units is determined using both the income and market valuation approaches. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows that the reporting unit is expected to generate over its remaining life. Under the market approach, the value of the reporting unit is based on an analysis that compares the value of the reporting unit to values of publicly traded companies in similar lines of business. In the application of the income and market valuation approaches, the Company is required to make estimates of future operating trends and judgments on discount rates and other variables. Actual future results related to assumed variables could differ from these estimates.
	Long-lived assets, such as property, plant, and equipment, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset, or asset group, to estimated undiscounted future cash flows expected to be generated by the asset, or asset group. An impairment charge is recognized by the amount by which the carrying amount of the asset, or asset group, exceeds its fair value.
	The Company amortizes intangible assets with estimable useful lives on a straight-line basis over their useful lives.
Revenue Recognition, Policy	'
	Revenue Recognition
	Revenue is recognized when all of the following criteria have been met:
	•	Persuasive evidence of an arrangement exists. The Company generally relies upon sales contracts or agreements, and customer purchase orders to determine the existence of an arrangement.
	•	Delivery has occurred. The Company uses shipping terms and related documents, or written evidence of customer acceptance, when applicable, to verify delivery or performance.
	•	Sales price is fixed or determinable. The Company assesses whether the sales price is fixed or determinable based on the payment terms and whether the sales price is subject to refund or adjustment.
	•	Collectability is reasonably assured. The Company assesses collectability based on creditworthiness of customers as determined by its credit checks, their payment histories, or changes in circumstances that indicate that collectability is not reasonably assured.
	When sales arrangements contain multiple elements, including software and non-software components that function together to deliver the tangible products' essential functionality, the Company allocates revenue to each element based on a selling price hierarchy. The selling price for a deliverable is based on either vendor-specific objective evidence (“VSOE”) if available, third-party evidence (“TPE”) if VSOE is not available, or estimated selling price (“ESP”) if neither VSOE nor TPE is available. The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. VSOE of selling price is based on the price charged when the element is sold separately. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonable range based on historical discounting trends for specific products and services. TPE of selling price is established by evaluating largely interchangeable competitor products or services in stand-alone sales to similarly situated customers. However, as the Company's products contain a significant element of proprietary technology and its solutions offer substantially different features and functionality, the comparable pricing of third-party products with similar functionality typically cannot be obtained. ESP is established considering multiple factors including, but not limited to pricing practices in different geographies and through different sales channels, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles.
	In multiple element arrangements where software deliverables are included, revenue is allocated to each separate unit of accounting for each of the non-software deliverables and to the software deliverables as a group using the relative selling prices of each of the deliverables in the arrangement based on the aforementioned selling price hierarchy. If the arrangement contains more than one software deliverable, the arrangement consideration allocated to the software deliverables as a group is then allocated to each software deliverable using the residual method when VSOE of fair value of the undelivered items exists. Under the residual method, the amount of revenue allocated to delivered elements equals the total arrangement consideration less the aggregate fair value of any undelivered elements. If VSOE of one or more undelivered items does not exist, revenue from the entire arrangement is deferred and recognized at the earlier of: (i) delivery of those elements or (ii) when fair value can be established unless maintenance services is the only undelivered element, in which case, the entire arrangement fee is recognized ratably over the maintenance service period.
	The Company limits the amount of revenue recognition for delivered elements to the amount that is not contingent on the future delivery of products or services or subject to customer-specific return or refund privileges.
	The Company records reductions to revenue for estimated product returns and pricing adjustments, such as rebates and price protection, in the same period that the related revenue is recorded. The amount of these reductions is based on historical sales returns and price protection credits, specific criteria outlined in rebate agreements, and other factors known at the time.
	A portion of the Company's sales is made through distributors under agreements allowing for pricing credits or rights of return. As reliable estimates of these credits or returns cannot be made, product revenue on sales made through these distributors is recognized upon sell-through as reported by the distributors to the Company. Deferred revenue on shipments to distributors reflects the effects of distributor pricing credits given and the amount of gross margin expected to be realized upon sell-through. Deferred revenue is recorded net of the related product costs of revenue.
	Service revenues include revenue from maintenance, training, and professional services. Maintenance is offered under renewable contracts. Revenue from maintenance service contracts is deferred and recognized ratably over the contractual support period, which is generally one to three years. Revenue from training and professional services is recognized as services are completed or ratably over the contractual period, which is generally one year or less.
Allowance For Doubtful Accounts, Policy	'
	Allowance for Doubtful Accounts
	The allowance for doubtful accounts is based on the Company's assessment of the collectability of customer accounts. The Company regularly reviews its receivables that remain outstanding past their applicable payment terms and establishes an allowance by considering factors such as historical experience, credit quality, age of the accounts receivable balances, and current economic conditions that may affect a customer's ability to pay.
Warranty Reserves, Policy	'
	Warranty Reserves
	The Company generally offers a one-year warranty on all of its hardware products, a 90-day warranty on the media that contains the software embedded in the products. Warranty costs are recognized as part of the Company's cost of sales based on associated material costs, labor costs, and overhead at the time revenue is recognized. Material costs are estimated primarily based upon the historical costs to repair or replace product returns within the warranty period. Labor and overhead costs are estimated primarily based upon historical trends in the cost to support customer cases within the warranty period.
Contract Manufacturer Liabilities, Policy	'
	Contract Manufacturer Liabilities
	The Company establishes a liability for non-cancelable, non-returnable purchase commitments with its contract manufacturers for carrying charges, quantities in excess of its demand forecasts, or obsolete material charges for components purchased by the contract manufacturers to meet the Company’s demand forecast or customer orders. The demand forecasts are based upon historical trends and analysis from the Company's sales and marketing organizations, adjusted for overall market conditions.
Research and Development Expense, Policy	'
	Research and Development
	Costs to research, design, and develop the Company's products are expensed as incurred.
Software Development Costs, Policy	'
	Software Development Costs
	Capitalization of software development costs for software to be sold, leased, or otherwise marketed begins when a product's technological feasibility has been established and ends when a product is available for general release to customers. Generally, the Company's products are released soon after technological feasibility has been established. As a result, costs incurred between achieving technological feasibility and product general availability have not been significant. The Company capitalizes costs associated with internal-use software systems that have reached the application development stage and are primarily attributable to the Company's enterprise resource planning ("ERP") implementation. Such capitalized costs include external direct costs utilized in developing or obtaining the applications and payroll and payroll-related costs for employees, who are directly associated with the development of the applications.
Advertising, Policy	'
	Advertising
	Advertising costs are charged to sales and marketing expense as incurred. Advertising expense was $20.1 million, $20.0 million, and $17.2 million, for 2013, 2012, and 2011, respectively.
Foreign Currency, Policy	'
	Foreign Currency
	Assets and liabilities of foreign operations with non-U.S. Dollar functional currency are translated to U.S. Dollars using exchange rates in effect at the end of the period. Revenue and expenses are translated to U.S. Dollars using average exchange rates for the period. The resulting translation adjustments are included in the Company’s Consolidated Balance Sheets in the stockholders’ equity section as a component of accumulated other comprehensive income. For the Company’s international subsidiaries in which the functional currency is the U.S. dollar, the Company records foreign exchange gains and losses for assets and liabilities in the Consolidated Statements of Operations. Remeasurement adjustments are recorded in other expense, net in the Consolidated Statements of Operations.
Loss Contingencies, Policy	'
	Loss Contingencies
	The Company is subject to the possibility of various loss contingencies arising in the ordinary course of business. Management considers the likelihood of loss related to an asset, or the incurrence of a liability, as well as its ability to reasonably estimate the amount of loss, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether such accruals should be adjusted and whether new accruals are required.
Share-Based Compensation, Policy	'
	Share-Based Compensation
	The Company utilizes the Black-Scholes-Merton (“BSM”) option-pricing model to estimate the fair value of its stock options and Employee Stock Purchase Plan ("ESPP") shares. The Company determines the fair value of its restricted stock units ("RSUs"), restricted stock awards ("RSAs"), and performance share awards ("PSAs") based on the closing market price of the Company’s common stock on the date of grant. Share-based compensation expense is based on the fair value of the underlying awards and amortized on a straight-line basis, net of estimated forfeitures. With respect to PSAs, that generally vest after three years, for the portion of the award attributable to each performance year, the Company recognizes PSA expense on a straight-line basis over the remaining vesting period starting in the period in which the annual performance targets are set for each such performance year, to the extent that the performance target is expected to be met.
	The BSM model requires various highly subjective assumptions that represent management's best estimates of volatility, risk-free interest rate, expected life, and dividend yield. The expected volatility is based on the implied volatility of market-traded options on the Company's common stock, adjusted for other relevant factors including historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected life of the Company’s stock options. The expected life of a stock option award is based on historical experience.
Provision for Income Taxes, Policy	'
	Provision for Income Taxes
	Deferred tax assets and liabilities are recognized for the expected tax consequences of temporary differences between the tax bases of assets and liabilities and their reported amounts. Valuation allowances are recorded to reduce deferred tax assets to the amount that will more likely than not be realized.
	The Company accounts for uncertainty in income taxes using a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon settlement. The Company classifies the liability for unrecognized tax benefits as current to the extent that the Company anticipates payment (or receipt) of cash within one year. Interest and penalties related to uncertain tax positions are recognized in the provision for income taxes.
Concentrations of Risk, Policy	'
	Concentrations of Risk
	Financial instruments that subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, investments, and accounts receivable. The Company invests only in high-quality credit instruments and maintains its cash, cash equivalents and available-for-sale investments in fixed income securities with several high-quality institutions. Deposits held with banks, including those held in foreign branches of global banks, may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand and, therefore, bear minimal credit risk.
	The Company’s derivatives expose it to credit risk to the extent that counterparties may be unable to meet the terms of the agreement. To mitigate concentration of risk related to its derivatives, the Company establishes counterparty limits to major credit-worthy financial institutions. In addition, the potential risk of loss with any one counterparty resulting from this type of credit risk is monitored and the derivatives transacted with these entities are relatively short in duration. Therefore, the Company does not expect material losses as a result of defaults by counterparties.
	Generally, credit risk with respect to accounts receivable is diversified due to the number of entities comprising the Company's customer base and their dispersion across different geographic locations throughout the world. The Company performs ongoing credit evaluations of its customers and generally does not require collateral on accounts receivable. During the years ended December 31, 2013 and December 31, 2011, no single customer accounted for 10% or more of net revenues. During the year ended December 31, 2012, Verizon Communications, Inc. ("Verizon") accounted for 10.3% of net revenues.
	The Company relies on sole suppliers for certain of its components such as application-specific integrated circuits ("ASICs") and custom sheet metal. Additionally, the Company relies primarily on a limited number of significant independent contract manufacturers for the production of its products. The inability of any supplier or manufacturer to fulfill supply requirements of the Company could negatively impact future operating results.
Use of Estimates, Policy	'
	Use of Estimates
	The preparation of the financial statements and related disclosures in conformity with U.S. GAAP requires the Company to make judgments, assumptions, and estimates that affect the amounts reported in the Consolidated Financial Statements and the accompanying notes. The Company bases its estimates and assumptions on current facts, historical experience, and various other factors that it believes are reasonable under the circumstances, to determine the carrying values of assets and liabilities that are not readily apparent from other sources. To the extent there are material differences between the Company's estimates and the actual results, the Company's future consolidated results of operation may be affected.
Recent Accounting Pronouncements, Policy	'
	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.

Significant_Accounting_Policie2

Significant Accounting Policies Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Accounting Policies [Abstract]	'
Property and equipment useful life [Table Text Block]	'
	Depreciation is calculated using the straight-line method, over the estimated useful lives of the following assets:
		Estimated Useful Life (years)
	Computers, equipment, and software	3 to 5
	Furniture and fixtures	5
	Building and building improvements	7 to 40
	Land improvements	10 to 40
	Leasehold improvements	Lease term, not to exceed 10 years

Business_Combinations_Tables

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2013							Dec. 31, 2012										Dec. 31, 2011
Business Combinations [Abstract]	'							'										'
Schedule of purchase consideration allocation for acquisitions [Table Text Block]	'							'										'
	The following table presents the purchase consideration allocations for these acquisitions based upon acquisition-date fair values, including cash and cash equivalents acquired (in millions):
		2013 Acquisitions		2012 Acquisitions		2011 Acquisitions
	Net tangible assets acquired	$	0.1	$	3.5	$	1.7
	Intangible assets acquired	9.9		54.1		28.4
	Goodwill	—		129.7		0.4
	Total	$	10	$	187.3	$	30.5
Finite-Lived and Indefinite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	'							'										'
								The following table presents details of the intangible assets acquired for the business combinations completed during 2012 as of their respective acquisition dates (in millions, except years):
																		The following table presents details of the intangible assets acquired for the business combinations completed during 2011 as of their respective acquisition dates (in millions, except years):
									Contrail			Mykonos			BitGravity
									Weighted	Amount		Weighted	Amount		Weighted	Amount			OpNext			Brilliant
									Average			Average			Average				Weighted Average	Amount		Weighted Average	Amount
									Estimated			Estimated			Estimated				Estimated Useful			Estimated Useful
									Useful			Useful			Useful				Life (In Years)			Life (In Years)
									Life			Life			Life			Existing or core technology	10	$	20.6	5	$	1.3
									(In Years)			(In Years)			(In Years)
								Existing technology	—	$	—	6	$	19.3	3	$	12.4	Support agreements and related relationships	4	5.1		—	—
								Trade name and trademarks	—	—		7	1		—	—		Patents	—	—		5	1.4
								In-process research and development	N/A	17.4		N/A	4		—	—		Total	9	$	25.7	5	$	2.7
								Total	—	$	17.4	6	$	24.3	3	$	12.4

Cash_Equivalents_and_Investmen1

Cash Equivalents and Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Cash Equivalents and Investments [Abstract]	'
Investments in available-for-sale and trading securities [Table Text Block]	'
	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 December 31, 2013 and December 31, 2012 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	As of December 31, 2013
	Fixed income securities:
	Asset-backed securities	$	249.9	$	0.1		$	(0.1	)	$	249.9
	Certificates of deposit	27.6		—			—			27.6
	Commercial paper	6.9		—			—			6.9
	Corporate debt securities	813.6		2			(0.3		)	815.3
	Foreign government debt securities	10.7		—			—			10.7
	Government-sponsored enterprise obligations	306.2		0.1			(0.1		)	306.2
	U.S. government securities	303.3		0.1			(0.1		)	303.3
	Total fixed income securities	1,718.20		2.3			(0.6		)	1,719.90
	Money market funds	1,043.70		—			—			1,043.70
	Mutual funds	3.9		0.1			—			4
	Publicly-traded equity securities	12		104.5			(1.9		)	114.6
	Total available-for-sale securities	2,777.80		106.9			(2.5		)	2,882.20
	Trading securities in mutual funds(*)	15.4		—			—			15.4
	Total	$	2,793.20	$	106.9		$	(2.5	)	$	2,897.60
	Reported as:
	Cash equivalents	$	996.2	$	—		$	—		$	996.2
	Restricted investments	87.5		0.1			—			87.6
	Short-term investments	459		104.9			(2.0		)	561.9
	Long-term investments	1,250.50		1.9			(0.5		)	1,251.90
	Total	$	2,793.20	$	106.9		$	(2.5	)	$	2,897.60
	________________________________
	(*)	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
	Fixed income securities:
	Asset-backed securities	$	226.2	$	0.3		$	(0.1	)	$	226.4
	Certificates of deposit	42.5		—			—			42.5
	Commercial paper	22.4		—			—			22.4
	Corporate debt securities	533.4		2.3			(0.1		)	535.6
	Foreign government debt securities	5		—			—			5
	Government-sponsored enterprise obligations	270.7		0.3			—			271
	U.S. government securities	494.4		0.1			—			494.5
	Total fixed income securities	1,594.60		3			(0.2		)	1,597.40
	Money market funds	1,145.20		—			—			1,145.20
	Mutual funds	2.9		0.1			—			3
	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 [Table Text Block]	'
	The following table presents the maturities of the Company's fixed income securities as of December 31, 2013 (in millions):
		Amortized		Gross Unrealized			Gross Unrealized			Estimated Fair
		Cost		Gains			Losses			Value
	Due within one year	$	467.7	$	0.3		$	—		$	468
	Due between one and five years	1,250.50		2			(0.6		)	1,251.90
	Total	$	1,718.20	$	2.3		$	(0.6	)	$	1,719.90
Available-for-sale investments in an unrealized loss position [Table Text Block]	'
	The following tables present the Company's available-for-sale securities that were in an unrealized loss position as of December 31, 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 December 31, 2013
	Fixed income securities:
	Asset-backed securities(1)	$	153	$	(0.1	)	$	0.6		$	—	$	153.6	$	(0.1	)
	Corporate debt securities(1)	156.1		(0.3		)	9.7			—		165.8		(0.3		)
	Foreign government debt securities(2)	10		—			—			—		10		—
	Government-sponsored enterprise obligations	123.1		(0.1		)	—			—		123.1		(0.1		)
	U.S. government securities	119.7		(0.1		)	—			—		119.7		(0.1		)
	Total fixed income securities	561.9		(0.6		)	10.3			—		572.2		(0.6		)
	Publicly-traded equity securities	6.8		(1.9		)	—			—		6.8		(1.9		)
	Total available-for sale securities	$	568.7	$	(2.5	)	$	10.3		$	—	$	579	$	(2.5	)
	________________________________
	(1) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2013.
	(2) Balance for less than 12 months include investments that were in an immaterial unrealized loss position as of December 31, 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 (1)	$	55.1	$	(0.1	)	$	0.1		$	—	$	55.2	$	(0.1	)
	Certificates of deposit(2)	0.3		—			—			—		0.3		—
	Commercial paper(2)	10		—			—			—		10		—
	Corporate debt securities	116		(0.1		)	—			—		116		(0.1		)
	Government-sponsored enterprise obligations(2)	30		—			—			—		30		—
	U.S. government securities(2)	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	)
	________________________________
	(1) Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of December 31, 2012.
	(2) Balance for less than 12 months include investments that were in an immaterial unrealized loss position as of December 31, 2012.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis [Table Text Block]	'
	The following tables provide a summary of assets and liabilities measured at fair value on a recurring basis and as reported in the Consolidated Balance Sheets (in millions):
		Fair Value Measurements at December 31, 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	$	—	$	249.9		$	—	$	249.9
	Certificates of deposit	—		27.6			—		27.6
	Commercial paper	—		6.9			—		6.9
	Corporate debt securities	—		815.3			—		815.3
	Foreign government debt securities	—		10.7			—		10.7
	Government-sponsored enterprise obligations	—		306.2			—		306.2
	Money market funds (1)	1,043.70		—			—		1,043.70
	Mutual funds (2)	4		—			—		4
	Publicly-traded equity securities	114.6		—			—		114.6
	U.S. government securities	197.2		106.1			—		303.3
	Total available-for-sale securities	1,359.50		1,522.70			—		2,882.20
	Trading securities in mutual funds (3)	15.4		—			—		15.4
	Derivative assets:
	Foreign exchange contracts	—		3			—		3
	Total assets measured at fair value	$	1,374.90	$	1,525.70		$	—	$	2,900.60
	Liabilities measured at fair value:
	Derivative liabilities:
	Foreign exchange contracts	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total liabilities measured at fair value	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total assets measured at fair value, reported as:
	Cash equivalents	$	965.1	$	31.1		$	—	$	996.2
	Restricted investments	87.6		—			—		87.6
	Short-term investments	246.5		315.4			—		561.9
	Long-term investments	75.7		1,176.20			—		1,251.90
	Prepaid expenses and other current assets	—		3			—		3
	Total assets measured at fair value	$	1,374.90	$	1,525.70		$	—	$	2,900.60
	Total liabilities measured at fair value, reported as:
	Other accrued liabilities	$	—	$	(0.7	)	$	—	$	(0.7	)
	Total liabilities measured at fair value	$	—	$	(0.7	)	$	—	$	(0.7	)
	________________________________
	(1)	Balance includes $83.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisitions 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 the 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 the investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis [Table Text Block]	'
	The following table presents assets measured at fair value on a nonrecurring basis and the related impairment losses included in the Consolidated Statements of Operations (in millions):
		As of December 31,
		2013					2012
		Fair Value		Losses			Fair Value		Losses
	Privately-held investments	$	2	$	(2.8	)	$	—	$	(20.0	)
	Purchased intangible assets, net	$	—	—			$	—	(5.4		)
	Total losses for nonrecurring basis			$	(2.8	)			$	(25.4	)

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments [Table Text Block]	'
	The notional amount of the Company's foreign currency derivatives are summarized as follows (in millions):
		As of December 31,
		2013		2012
	Cash flow hedges	$	137.6	$	85.8
	Non-designated derivatives	144.4		112.8
	Total	$	282	$	198.6

Goodwill_and_Purchased_Intangi1

Goodwill and Purchased Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill [Table Text Block]	'
	The following table presents the goodwill activity allocated to the Company's reportable segments (in millions):
		PSD			SSD			Total
	December 31, 2011	$	1,795.60		$	2,132.50		$	3,928.10
	Additions due to business combinations	70.7			59.6			130.3
	Adjustments to goodwill	—			(0.6		)	(0.6		)
	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		)
	31-Dec-13	$	1,616.60		$	2,441.10		$	4,057.70
Purchased Intangible Assets [Table Text Block]	'
	The Company’s purchased intangible assets were as follows (in millions):
		Gross			Accumulated			Impairments and			Net
					Amortization			Other Charges
	As of December 31, 2013
	Intangible assets with finite lives:
	Technologies and patents	$	581.4		$	(453.4	)	$	(30.5	)	$	97.5
	Customer contracts, support agreements, and	74.3			(62.7		)	(2.2		)	9.4
	related relationships
	Total purchased intangible assets	$	655.7		$	(516.1	)	$	(32.7	)	$	106.9
	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
	Total intangible assets with finite lives	628.4			(484.2		)	(32.7		)	111.5
	IPR&D with indefinite lives	17.4			—			—			17.4
	Total purchased intangible assets	$	645.8		$	(484.2	)	$	(32.7	)	$	128.9
Schedule of Intangible Assets Amortization Included in Consolidated Statements of Operations [Table Text Block]	'
	The following table presents the amortization of intangible assets included in the Consolidated Statements of Operations (in millions):
		Years Ended December 31,
		2013			2012			2011
	Cost of revenues	$	27.3		$	27.6		$	21.7
	Operating expenses:
	Sales and marketing	3.4			3.5			4.1
	General and administrative	1.2			1.2			1.3
	Total operating expenses	4.6			4.7			5.4
	Total	$	31.9		$	32.3		$	27.1
Estimated Future Amortization Expense of Purchased Intangible Assets with Finite Lives [Table Text Block]	'
	December 31, 2013, the estimated future amortization expense of purchased intangible assets with finite lives is as follows (in millions):
	Years Ending December 31,	Amount
	2014	$	36.2
	2015	32.6
	2016	18.5
	2017	10.5
	2018	3.7
	Thereafter	5.4
	Total	$	106.9

Other_Financial_Information_Ta

Other Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Other Financial Information [Abstract]	'
Inventories [Table Text Block]	'
	Inventories are reported within prepaid expenses and other current assets and other long-term assets in the Consolidated Balance Sheets and consisted of the following (in millions):
		As of December 31,
		2013			2012
	Production materials	$	51.3		$	53.1
	Finished goods	1.4			4.1
	Inventories	$	52.7		$	57.2
Property and Equipment [Table Text Block]	'
	Property and equipment, net, consisted of the following (in millions):
		As of December 31,
		2013			2012
	Computers and equipment	$	794.6		$	711.8
	Software	108.4			106.6
	Leasehold improvements	202.6			206.5
	Furniture and fixtures	42.5			28.7
	Building and building improvements	242.6			206.1
	Land and land improvements	238.9			208.2
	Construction-in-process	79.5			112.7
	Property and equipment, gross	1,709.10			1,580.60
	Accumulated depreciation	(826.8		)	(768.7		)
	Property and equipment, net	$	882.3		$	811.9
Other Long-term Assets [Table Text Block]	'
	Other long-term assets consisted of the following (in millions):
		As of December 31,
		2013			2012
	Privately-held investments	$	57.2		$	32
	Licensed software	90.4			84.4
	Federal income tax receivable	20			—
	Financed customer receivable	19.9			—
	Inventory	15.2			—
	Prepaid costs, deposits, and other	31.1			21.9
	Other long-term assets	$	233.8		$	138.3
Warranties [Table Text Block]	'
	Changes in the Company’s warranty reserve were as follows (in millions):
		As of December 31,
		2013			2012
	Beginning balance	$	29.7		$	28.3
	Provisions made during the period, net	28.8			31.9
	Adjustments related to pre-existing warranties	(2.1		)	—
	Actual costs incurred during the period	(28.4		)	(30.5		)
	Ending balance	$	28		$	29.7
Deferred revenue [Table Text Block]	'
	Details of the Company's deferred revenue, as reported in the Consolidated Balance Sheets, were as follows (in millions):
		As of December 31,
		2013			2012
	Deferred product revenue:
	Undelivered product commitments and other product deferrals	$	184.9		$	256.9
	Distributor inventory and other sell-through items	118.7			138.4
	Deferred gross product revenue	303.6			395.3
	Deferred cost of product revenue	(58.6		)	(99.4		)
	Deferred product revenue, net	245			295.9
	Deferred service revenue	824.3			627.5
	Total	$	1,069.30		$	923.4
	Reported as:
	Current	$	705.8		$	693.5
	Long-term	363.5			229.9
	Total	$	1,069.30		$	923.4
Other Expense, Net [Table Text Block]	'
	Other expense, net consisted of the following (in millions):
		Years Ended December 31,
		2013			2012			2011
	Interest income	$	8.7		$	11		$	9.7
	Interest expense	(58.4		)	(52.9		)	(49.5		)
	Other	9.3			25.3			(7.0		)
	Other expense, net	$	(40.4	)	$	(16.6	)	$	(46.8	)

Restructuring_and_Other_Charge1

Restructuring and Other Charges (Tables)	12 Months Ended
	Dec. 31, 2013
Restructuring and Related Activities [Abstract]	'
Summary of restructuring charges [Table Text Block]	'
	The following table presents restructuring and other charges included in cost of revenues and restructuring and other charges in the Consolidated Statements of Operations under the Company's restructuring plans (in millions):
		Years Ended December 31,
		2013		2012		2011
	Severance	$	22.9	$	36.7	$	15.3
	Facilities	10		5.8		0.2
	Contract terminations and other	14.6		57.2		15.1
	Total	$	47.5	$	99.7	$	30.6
	Reported as:
	Cost of revenues	$	8.4	$	52.9	$	—
	Restructuring and other charges	39.1		46.8		30.6
	Total	$	47.5	$	99.7	$	30.6
Changes in the restructuring liability [Table Text Block]	'
	The following table provides a summary of changes in the restructuring liability related to the Company's plans as of December 31, 2013 (in millions):
		December 31,		Charges		Cash			Non-cash			December 31,
		2012				Payments			Settlements and			2013
									Other
	Severance	$	10.6	$	22.9	$	(27.8	)	$	(0.1	)	$	5.6
	Facilities	5.2		10		(6.0		)	(4.1		)	5.1
	Contract terminations and other	2.4		14.6		(9.3		)	(0.6		)	7.1
	Total	$	18.2	$	47.5	$	(43.1	)	$	(4.8	)	$	17.8

LongTerm_Debt_and_Financing_Ta

Long-Term Debt and Financing (Tables)	12 Months Ended
	Dec. 31, 2013
Debt Instruments [Abstract]	'
Long-term Debt [Table Text Block]	'
	The following table summarizes the Company's long-term debt (in millions, except percentages):
		As of December 31, 2013
		Amount			Effective Interest
					Rates
	Senior notes:
	3.10% fixed-rate notes, due 2016	$	300		3.12	%
	4.60% fixed-rate notes, due 2021	300			4.63	%
	5.95% fixed-rate notes, due 2041	400			6.01	%
	Total senior notes	1,000.00
	Unaccreted discount	(0.7		)
	Total	$	999.3

Equity_Equity_Tables

Equity Equity (Tables)	12 Months Ended
	Dec. 31, 2013
Equity [Abstract]	'
Repurchase and Retirement of Common Stock and Net Issuances [Table Text Block]	'
	The following table summarizes the Company's repurchases and retirements of its common stock under its stock repurchase programs and repurchases associated with minimum tax withholdings (in millions, except per share amounts):
		Shares			Average price				Amount
		Repurchased			per share				Repurchased
	2013
	Repurchases under stock repurchase programs	28.9			$	19.76			$	570.6
	Repurchases for tax withholding	0.4			$	20.23			$	7.2
	2012
	Repurchases under stock repurchase programs	35.8			$	18.05			$	645.6
	Repurchases for tax withholding	0.2			$	23.4			$	5
	2011
	Repurchases under stock repurchase programs	17.5			$	30.93			$	541.2
	Repurchases for tax withholding	0.2			$	35.98			$	7.4
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	The components of accumulated other comprehensive income, net of related taxes, as of December 31, 2013 and December 31, 2012 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, 2011	$	0.1			$	(10.9	)		$	(6.8	)	$	(17.6	)
	Other comprehensive gain before reclassifications	3.2				7.4				6.4			17
	Amount reclassified from accumulated other	(1.2		)		6.5				—			5.3
	comprehensive income
	Other comprehensive gain	2				13.9				6.4			22.3
	Balance as of December 31, 2012	$	2.1			$	3			$	(0.4	)	$	4.7
	Other comprehensive gain (loss) before reclassifications	65.1				0.7				(3.4		)	62.4
	Amount reclassified from accumulated other	(1.0		)		(1.5		)		—			(2.5		)
	comprehensive income
	Other comprehensive gain (loss)	64.1				(0.8		)		(3.4		)	59.9
	Balance as of December 31, 2013	$	66.2			$	2.2			$	(3.8	)	$	64.6
	________________________________
	(1)	The reclassifications out of accumulated other comprehensive income during the years ended December 31, 2013 and December 31, 2012 for realized gains on available-for-sale securities of $1.0 million and $1.2 million, respectively, are included in other expense, net, in the Consolidated Statements of Operations.
	(2)	The reclassifications out of accumulated other comprehensive income during the year ended December 31, 2013 for realized gains on cash flow hedges are included within cost of revenues of $1.1 million and sales and marketing of $4.3 million and for realized losses within research and development of $3.4 million and general and administrative of $0.5 million for which the hedged transactions relate in the Consolidated Statements of Operations. The reclassifications out of accumulated other comprehensive income during the year ended December 31, 2012 for realized losses on cash flow hedges are included within cost of revenues of $0.9 million, research and development of $2.3 million, sales and marketing of $2.0 million, and general and administrative of $1.3 million for which the hedged transactions relate in the Consolidated Statements of Operations.

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	'
	The following table summarizes the Company’s stock option activity and related information as of and for the three years ended December 31, 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, 2010	49.4			$	21.9			4.1		$	744.5
	Granted	5.6			37.17
	Canceled	(1.9	)		26.76
	Exercised	(13.9	)		21.13
	Expired	(0.6	)		34.32
	Balance as of December 31, 2011	38.6			$	23.98			3.7		$	75.3
	Granted	3.1			22.81
	Assumed(*)	0.9			0.57
	Canceled	(2.8	)		26.64
	Exercised	(3.6	)		11.71
	Expired	(2.1	)		26.97
	Balance as of December 31, 2012	34.1			$	24.13			3.1		$	52.5
	Granted	—			—
	Canceled	(1.3	)		29.56
	Exercised	(5.6	)		15.58
	Expired	(4.1	)		28.35
	Balance as of December 31, 2013	23.1			$	25.15			2.4		$	44.6
	As of December 31, 2013:
	Vested and expected-to-vest options	22.8			$	25.24			2.4		$	42
	Exercisable options	20.5			$	25.4			2		$	30
	_____________________________
	(*)	Stock options assumed in connection with the acquisition of Contrail.
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]	'
	The following table summarizes additional information regarding outstanding and exercisable options as of December 31, 2013:
			Options Outstanding									Options Exercisable
	Range of Exercise Price		Number Outstanding			Weighted Average		Weighted Average				Number	Weighted Average
	(In dollars)		(In millions)			Remaining		Exercise Price				Exercisable	Exercise Price
						Contractual Life		(In dollars)				(In millions)	(In dollars)
						(In years)
	$0.03 - $15.09		2.9			3.9		$	10.89			2.3	$	13.76
	$16.00 - $21.12		2.4			1.4		18.41				2.3	18.33
	$21.43 - $23.84		2.4			2.2		22.46				2.1	22.6
	$23.89 - $24.20		2.6			2.3		24.16				2.1	24.15
	$24.25 - $25.49		2.3			1.3		25.07				2.3	25.07
	$25.50 - $26.90		3.2			1.8		26.55				3.2	26.55
	$26.97 - $29.89		3.1			2.6		28.54				2.9	28.52
	$29.93 - $38.93		2.2			2.2		33.31				1.9	33.16
	$40.26 - $40.26		1.1			4		40.26				0.8	40.26
	$44.00 - $44.00		0.9			4.1		44				0.6	44
	$0.03 - $44.00		23.1			2.4		$	25.15			20.5	$	25.4
Schedule of Nonvested Share Activity [Table Text Block]	'
	The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the three years ended December 31, 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, 2010	14.2			$	25.94			1.7		$	522.9
	RSUs granted	7.3			31.75
	PSAs granted(1)	4.5			38.64
	RSUs vested(6)	(1.7	)		23.26
	PSAs vested(6)	(0.8	)		24.76
	RSUs canceled	(1.0	)		31.57
	PSAs canceled	(2.9	)		30.72
	Balance as of December 31, 2011	19.6			$	30.27			1.5		$	400.5
	RSUs granted	9.9			20.79
	RSUs assumed(3)(4)	0.2			22.21
	PSAs granted(2)	2.2			23.07
	RSAs assumed(4)	5.8			19.59
	RSUs vested(6)	(3.1	)		27.04
	PSAs vested(6)	(1.9	)		18.21
	RSAs vested(6)	(0.7	)		19.59
	RSUs canceled	(2.9	)		27.77
	PSAs canceled	(2.3	)		29.71
	Balance as of December 31, 2012	26.8			$	27.76			1.7		$	565
	RSUs granted	10.3			20.32
	PSAs granted(5)	2.2			21.27
	RSUs vested(6)	(6.1	)		26.15
	PSAs vested(6)	(1.1	)		28.52
	RSAs vested(6)	(1.6	)		19.59
	RSUs canceled	(3.4	)		22.99
	PSAs canceled	(1.7	)		29.1
	Balance at December 31, 2013	25.4			$	23.44			1.1		$	573.5
	As of December 31, 2013:
	Vested and expected-to-vest RSUs, RSAs	20.8			$	23.77			1		$	469.2
	and PSAs
	________________________________
	(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 is estimated at 1.9 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 4.5 million shares.
	(2)	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 0.9 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.
	(3)	RSUs assumed in connection with the acquisition of Mykonos.
	(4)	RSUs and RSAs assumed in connection with the acquisition of Contrail.
	-5	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.
	-6	Total fair value of RSUs, RSAs, and PSAs vested during 2013, 2012, and 2011 was $221.5 million, $132.0 million, and $57.7 million, respectively.
Shares available for grant [Table Text Block]	'
	The following table presents the stock activity and the total number of shares available for grant under the 2006 Plan as of December 31, 2013 (in millions):
		Number of Shares
	Balance as of December 31, 2012	57.3
	RSUs and PSAs granted (1)	(26.1	)
	RSUs and PSAs canceled (1)	12.6
	Options canceled (2)	1.2
	Options expired (2)	4.1
	Balance as of December 31, 2013	49.1
	________________________________
	(1)	RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant under the 2006 Plan are counted against shares authorized under the plan as two and one-tenth shares of common stock for each share subject to such award. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term.
	(2)	Includes canceled or expired options under the 1996 Plan and the 2000 Plan that expired after May 18, 2006, which become available for grant under the 2006 Plan according to its terms.
Schedule Of Share-based Payment Award, Stock Options and Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	'
	The weighted-average assumptions used and the resulting estimates of fair value for stock options and ESPP were as follows:
		Years Ended December 31,
		2013		2012		2011
	Stock Options:
	Volatility	—		45%		43%
	Risk-free interest rate	—		0.70%		1.50%
	Expected life (years)	0 years		4.2		4.1
	Dividend yield	—		—		—
	Weighted-average fair value per share	—		$8.47		$13.17
	ESPP:
	Volatility	36%		47%		41%
	Risk-free interest rate	0.10%		0.10%		0.20%
	Expected life (years)	0.5		0.5		0.5
	Dividend yield	—		—		—
	Weighted-average fair value per share	$5.54		$5.53		$7.48
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	'
	Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and ESPP was recorded in the following cost and expense categories in the Company's Consolidated Statements of Operations (in millions):
		Years Ended December 31,
		2013				2012				2011
	Cost of revenues - Product	$	4.7			$	4.6			$	4.6
	Cost of revenues - Service	15.4				17				15.7
	Research and development	127.6				109.1				97.7
	Sales and marketing	70.9				81.6				70.9
	General and administrative	26				31.1				33.3
	Total	$	244.6			$	243.4			$	222.2
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	'
	The following table summarizes share-based compensation expense by award type (in millions):
		Years Ended December 31,
		2013				2012				2011
	Stock options	$	31.5			$	58.9			$	76.2
	RSUs, RSAs, and PSAs	196.8				163.7				127.5
	ESPP	16.3				20.8				18.5
	Total	$	244.6			$	243.4			$	222.2
Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]	'
	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 December 31, 2013 (in millions, except years):
		Unrecognized				Weighted Average
		Compensation Cost				Period
						(In Years)
	Stock options	$	33.6			1.8
	RSUs, RSAs, and PSAs	$	279.1			1.8

Segments_Tables

Segments (Tables)	12 Months Ended
	Dec. 31, 2013
Segment Reporting [Abstract]	'
Financial information for each segment [Table Text Block]	'
	The following table summarizes financial information for each segment used by the CODM (in millions):
		Years Ended December 31,
		2013			2012			2011
	PSD product revenues:
	Routing	$	2,243.60		$	1,946.80		$	2,166.10
	Switching	638			554.8			495.8
	Total PSD product revenues	2,881.60			2,501.60			2,661.90
	PSD service revenues	796.6			769.2			645
	Total PSD revenues	3,678.20			3,270.80			3,306.90
	SSD product revenues:
	Security	564.3			669.9			698.3
	Routing	74			90.6			118.1
	Total SSD product revenues	638.3			760.5			816.4
	SSD service revenues	352.6			334.1			325.4
	Total SSD revenues	990.9			1,094.60			1,141.80
	Total net revenues	$	4,669.10		$	4,365.40		$	4,448.70
	Segment contribution margin:
	PSD	$	1,621.00		$	1,276.40		$	1,426.80
	SSD	398.4			473.6			504.4
	Total segment contribution margin	2,019.40			1,750.00			1,931.20
	Corporate unallocated expenses (1)	(1,123.5		)	(1,068.7		)	(1,013.9		)
	Amortization of purchased intangible assets (2)	(31.9		)	(32.3		)	(27.1		)
	Share-based compensation expense	(244.6		)	(243.4		)	(222.2		)
	Share-based payroll tax expense	(5.1		)	(1.1		)	(9.3		)
	Restructuring and other charges (3)	(47.5		)	(99.7		)	(30.6		)
	Acquisition-related charges (4)	(0.9		)	(2.0		)	(9.6		)
	Other unallocated expense	—			5.3			—
	Total operating income	565.9			308.1			618.5
	Other expense, net	(40.4		)	(16.6		)	(46.8		)
	Income before income taxes and noncontrolling interest	$	525.5		$	291.5		$	571.7
	________________________________
	(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.
	(4)	Amount includes acquisition-related costs reported in cost of revenues and operating expenses
Net revenues by geographic region [Table Text Block]	'
	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):
		Years Ended December 31,
		2013			2012			2011
	Americas:
	United States	$	2,381.50		$	2,067.50		$	2,015.80
	Other	232			218.4			222.2
	Total Americas	2,613.50			2,285.90			2,238.00
	Europe, Middle East, and Africa	1,256.90			1,266.30			1,339.80
	Asia Pacific	798.7			813.2			870.9
	Total	$	4,669.10		$	4,365.40		$	4,448.70
Property and equipment by geographic region [Table Text Block]	'
	The following table presents geographic information for property and equipment, net (in millions):
		As of December 31,
		2013			2012
	United States	$	801.3		$	725.5
	International	81			86.4
	Property and equipment, net	$	882.3		$	811.9

Income_Taxes_Income_Taxes_Tabl

Income Taxes Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Tax Disclosure [Abstract]	'
Components of income before the provision for income taxes and noncontrolling interest [Table Text Block]	'
	The components of income before the provision for income taxes and noncontrolling interest are summarized as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Domestic	$	248.7		$	114.1		$	218.4
	Foreign	276.8			177.4			353.3
	Total income before provision for income taxes and	$	525.5		$	291.5		$	571.7
	noncontrolling interest
Schedule of Components of Provision for Income Taxes [Table Text Block]	'
	The provision for income taxes is summarized as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Current provision:
	Federal	$	(12.9	)	$	94.3		$	19.5
	States	(5.0		)	8.4			0.9
	Foreign	32.5			37.1			47.8
	Total current provision	14.6			139.8			68.2
	Deferred provision (benefit):
	Federal	51.2			(28.8		)	23
	States	(2.7		)	(1.5		)	0.6
	Foreign	22.6			3.5			(3.6		)
	Total deferred provision (benefit)	71.1			(26.8		)	20
	Income tax benefits attributable to employee stock plan activity	—			(8.0		)	58.5
	Total provision for income taxes	$	85.7		$	105		$	146.7
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	'
	The provision for income taxes differs from the amount computed by applying the federal statutory rate to income before provision for income taxes as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Expected provision at 35% rate	$	184		$	102		$	200.1
	State taxes (benefit), net of federal benefit	(3.6		)	2			2
	Foreign income at different tax rates	(37.7		)	(11.6		)	(50.4		)
	Research and development credits	(32.5		)	(0.5		)	(21.3		)
	Share-based compensation	25.6			22.4			16.7
	Settlement with tax authorities	(28.3		)	—			—
	Domestic production activities	(26.3		)	—			—
	Equity investment gain on acquisition	—			(5.3		)	—
	Other	4.5			(4.0		)	(0.4		)
	Total provision for income taxes	$	85.7		$	105		$	146.7
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	'
	Significant components of the Company's deferred tax assets and liabilities are as follows (in millions):
		As of December 31,
		2013			2012
	Deferred tax assets:
	Net operating loss carry-forwards	$	1.1		$	10
	Foreign tax credit carry-forwards	63.4			58
	Research and other credit carry-forwards	106.6			95.3
	Deferred revenue	71			98.6
	Stock-based compensation	86.1			97.5
	Reserves and accruals not currently deductible	153.9			175.2
	Other	13.7			13.6
	Total deferred tax assets	495.8			548.2
	Valuation allowance	(155.7		)	(141.0		)
	Deferred tax assets, net of valuation allowance	340.1			407.2
	Deferred tax liabilities:
	Property and equipment basis differences	(3.1		)	(1.0		)
	Purchased intangibles	(10.1		)	(40.8		)
	Unremitted foreign earnings	(258.9		)	(229.1		)
	Deferred compensation and other	(38.7		)	—
	Other	(0.4		)	(1.2		)
	Total deferred tax liabilities	(311.2		)	(272.1		)
	Net deferred tax assets	$	28.9		$	135.1
Reconciliation of Unrecognized Tax Benefits [Table Text Block]	'
	A reconciliation of the beginning and ending amount of the Company's total gross unrecognized tax benefits was as follows (in millions):
		Years Ended December 31,
		2013			2012			2011
	Balance at beginning of year	$	136.1		$	132.2		$	116.4
	Tax positions related to current year:
	Additions	15.8			8.8			17.6
	Tax positions related to prior years:
	Additions	22.6			0.9			6.4
	Reductions	(2.2		)	—			—
	Settlements	(31.1		)	(1.2		)	(5.4		)
	Lapses in statutes of limitations	(3.6		)	(4.6		)	(2.8		)
	Balance at end of year	$	137.6		$	136.1		$	132.2
Schedule of Breakdown Between Current and Long-term Deferred Tax Assets and Deferred Tax Liabilities [Table Text Block]	'
	The breakdown between current and long-term deferred tax assets and deferred tax liabilities are as follows (in millions):
		As of December 31,
		2013			2012
	Current deferred tax assets	$	79.8		$	172.6
	Current deferred tax liabilities	—			—
	Long-term deferred tax assets	2.4			—
	Long-term deferred tax liabilities	(53.3		)	(37.5		)
	Total net deferred tax assets	$	28.9		$	135.1

Net_Income_per_Share_Tables

Net Income per Share (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings Per Share [Abstract]	'
Schedule of Calculation of Basic and Diluted Net Income Per Share [Table Text Block]	'
	The Company computed basic and diluted net income per share attributable to Juniper Networks common stockholders as follows (in millions, except per share amounts):
		Years Ended December 31,
		2013		2012		2011
	Numerator:
	Net income attributable to Juniper Networks	$	439.8	$	186.5	$	425.1
	Denominator:
	Weighted-average shares used to compute basic net income per share	501.8		520.9		529.8
	Dilutive effect of employee stock awards	8.5		5.3		11.6
	Weighted-average shares used to compute diluted net income	510.3		526.2		541.4
	per share
	Net income per share attributable to Juniper Networks common
	stockholders:
	Basic	$	0.88	$	0.36	$	0.8
	Diluted	$	0.86	$	0.35	$	0.79

Commitments_and_Contingencies_1

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	'
	The following table summarizes the Company’s future minimum payments under non-cancelable operating leases for each of the next five years and thereafter as of December 31, 2013 (in millions):
	Years Ending December 31,	Amount
	2014	$	49.4
	2015	38.4
	2016	31.1
	2017	26.8
	2018	22.6
	Thereafter	56.9
	Total	$	225.2

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2013
Selected Quarterly Financial Information [Abstract]	'
Schedule of Selected Quarterly Financial Data (Unaudited) [Table Text Block]	'
	The tables below set forth selected unaudited financial data for each quarter of the two years ended December 31, 2013 (in millions, except per share amounts):
	Year Ended December 31, 2013		First Quarter			Second Quarter			Third Quarter			Fourth Quarter
	Net revenues:
	Product		$	781.8		$	863.8		$	900.8		$	973.5
	Service		277.4			286.9			284.8			300.1
	Total net revenues		1,059.20			1,150.70			1,185.60			1,273.60
	Cost of revenues:
	Product		278.2			321.3			325.5			351.6
	Service		110.2			108.9			113.6			118.4
	Total cost of revenues (2)		388.4			430.2			439.1			470
	Gross margin		670.8			720.5			746.5			803.6
	Operating expenses:
	Research and development(1)		262.2			257.7			264.6			258.7
	Sales and marketing(4)		256.1			267.1			269.5			283.2
	General and administrative(4)		58.5			49.2			61.4			48.2
	Restructuring and other charges(2)		7			8			6			18.1
	Total operating expenses		583.8			582			601.5			608.2
	Operating income		87			138.5			145			195.4
	Other expense, net		(10.1		)	(12.6		)	(7.5		)	(10.2		)
	Income before income taxes		76.9			125.9			137.5			185.2
	Income tax (benefit) provision		(14.1		)	28			38.4			33.4
	Net income		$	91		$	97.9		$	99.1		$	151.8
	Net income per share:(3)
	Basic		$	0.18		$	0.19		$	0.2		$	0.3
	Diluted		$	0.18		$	0.19		$	0.19		$	0.3
	_______________________________
	(1)	In the second quarter of 2013, the Company extended the useful lives of certain computers and equipment based on 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. This change in accounting estimate decreased depreciation expense within research and development expense by approximately $11.0 million or $0.01 per diluted share for the second quarter of 2013, $9.4 million or $0.01 for the third quarter of 2013, and $7.9 million or $0.01 for the fourth quarter of 2013.
	(2)	In the third quarter of 2013, the Company implemented the 2013 Restructuring Plan for workforce reductions, contract terminations, and project cancellations and recorded restructuring charges of $7.4 million and $3.7 million to operating expenses and cost of revenues, respectively. In the fourth quarter of 2013, the Company continued to implement restructuring activities under the 2013 Restructuring Plan and primarily recorded charges to operating expenses of $17.6 million.
	(3)	Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.
	(4)	Certain amounts in the prior quarters' Condensed Consolidated Statements of Operations have been reclassified to conform to the current year presentation.
	Year Ended December 31, 2012		First Quarter			Second Quarter			Third Quarter(1)			Fourth Quarter
	Net revenues:
	Product		$	771.9		$	804.7		$	838.2		$	847.3
	Service		260.6			269.1			280.1			293.5
	Total net revenues		1,032.50			1,073.80			1,118.30			1,140.80
	Cost of revenues:
	Product		280.6			292.6			334.7			296.1
	Service		117.8			113.3			109.8			111.7
	Total cost of revenues(2)		398.4			405.9			444.5			407.8
	Gross margin		634.1			667.9			673.8			733
	Operating expenses:
	Research and development		269.6			268.7			288.2			275.1
	Sales and marketing(4)		258.6			260.4			261.8			264.7
	General and administrative(4)		56.2			48.9			50			51.7
	Restructuring and other charges(2)		2			3.2			31			10.6
	Total operating expenses		586.4			581.2			631			602.1
	Operating income		47.7			86.7			42.8			130.9
	Other (expense) income, net		(24.4		)	2.8			(4.0		)	9
	Income before income taxes		23.3			89.5			38.8			139.9
	Income tax provision		7			31.8			22			44.2
	Net income		$	16.3		$	57.7		$	16.8		$	95.7
	Net income per share(3)
	Basic		$	0.03		$	0.11		$	0.03		$	0.19
	Diluted		$	0.03		$	0.11		$	0.03		$	0.19
	_______________________________
	-1	During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.
	-2	In the third quarter of 2012, the Company implemented the 2012 Restructuring Plan for workforce reductions, facility consolidations or closures, and supply chain and procurement efficiencies and recorded restructuring charges of $29.5 million. In connection with its restructuring activities, the Company also recorded certain inventory and intangible asset impairment charges totaling $52.4 million to cost of revenues. In the fourth quarter of 2012, the Company continued to implement restructuring activities under the 2012 Restructuring Plan.
	(3)	Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.

Description_of_Business_and_Ba1

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

Significant_Accounting_Policie3

Significant Accounting Policies (Details) (USD $)

12 Months Ended

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Dec. 31, 2013

Dec. 31, 2012

Customer Concentration Risk [Member]

Customer Concentration Risk [Member]

Performance Shares (PSAs) [Member]

Minimum [Member]

Maximum [Member]

Computer, Equipment and Software [Member]

Computer, Equipment and Software [Member]

Furniture and fixtures [Member]

Building and building Improvements [Member]

Building and building Improvements [Member]

Land Improvements [Member]

Land Improvements [Member]

Leasehold improvements [Member]

Depreciable Assets [Member]

Depreciable Assets [Member]

Depreciable Assets [Member]

Depreciable Assets [Member]

Sales Revenue, Segment [Member]

Customer

Customer

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

Verizon [Member]

Customer Concentration Risk [Member]

Significant Accounting Policies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity of Highly Liquid Investments

'3 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturity period of non designated hedges derivatives

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maturities of Cash Flow Hedge Derivatives

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and Equipment, Useful Life

'

'

'

'

'

'

'

'

'3 years

'5 years

'5 years

'7 years

'40 years

'10 years

'40 years

'10 years

'

'

'

'

'

Change in accounting estimate- depreciation expense impact

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

($7.90)

($9.40)

($11)

$28.30

'

Change in accounting estimate, diluted net income per share impact

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$0.01

$0.01

$0.01

$0.04

'

Contractual Period

'

'

'

'

'

'

'1 year

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

Contractual Support Period

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warranty Period Hardware (in years)

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warranty Period Software (in days)

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Advertising Expense

$20.10

$20

$17.20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Award vesting period

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

More than likely percentage of being realized upon settlement, tax benefit

50.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liability for unrecognized tax benefits as current

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Customers Accounting for Ten Percent or More of Net Revenues

'

'

'

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Concentration Risk, Percentage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

10.30%

Business_Combinations_Purchase

Business Combinations, Purchase Price Allocation (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Business Acquisition [Line Items]	'	'	'
Goodwill	$4,057.70	$4,057.80	$3,928.10
2013 Acquisitions [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Net tangible assets acquired	0.1	'	'
Intangible assets acquired	9.9	'	'
Goodwill	0	'	'
Total	10	'	'
2012 Acquisitions [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Net tangible assets acquired	'	3.5	'
Intangible assets acquired	'	54.1	'
Goodwill	'	129.7	'
Total	'	187.3	'
2011 Acquisitions [Member]	'	'	'
Business Acquisition [Line Items]	'	'	'
Net tangible assets acquired	'	'	1.7
Intangible assets acquired	'	'	28.4
Goodwill	'	'	0.4
Total	'	'	$30.50

Business_Combinations_Intangib

Business Combinations, Intangible Assets Acquired (Details) (USD $)

Dec. 31, 2012

Dec. 14, 2012

Dec. 14, 2012

Dec. 14, 2012

Dec. 14, 2012

Feb. 13, 2012

Feb. 13, 2012

Feb. 13, 2012

Feb. 13, 2012

Mar. 08, 2012

Mar. 08, 2012

Mar. 08, 2012

Mar. 08, 2012

Dec. 31, 2011

Feb. 09, 2011

Feb. 09, 2011

Feb. 09, 2011

Feb. 09, 2011

Feb. 18, 2011

Feb. 18, 2011

Feb. 18, 2011

Feb. 18, 2011

In Millions, unless otherwise specified

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity OpNext [Member]

Business Acquisition Acquired Entity OpNext [Member]

Business Acquisition Acquired Entity OpNext [Member]

Business Acquisition Acquired Entity OpNext [Member]

Business Acquisition Acquired Entity Brilliant [Member]

Business Acquisition Acquired Entity Brilliant [Member]

Business Acquisition Acquired Entity Brilliant [Member]

Business Acquisition Acquired Entity Brilliant [Member]

In Process Research and Development [Member]

Existing technology [Member]

Trade name and trademarks [Member]

In Process Research and Development [Member]

Existing technology [Member]

Trade name and trademarks [Member]

In Process Research and Development [Member]

Existing technology [Member]

Trade name and trademarks [Member]

Existing technology [Member]

Support agreements and related relationships [Member]

Patents [Member]

Existing technology [Member]

Support agreements and related relationships [Member]

Patents [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Acquired finite-lived intangible asset, weighted average estimated useful life (in years)

'

'

'

'

'

'6 years

'

'6 years

'7 years

'3 years

'

'3 years

'

'

'9 years

'10 years

'4 years

'

'5 years

'5 years

'

'5 years

Intangible assets acquired

$54.10

$17.40

$17.40

$0

$0

$24.30

$4

$19.30

$1

$12.40

$0

$12.40

$0

$28.40

$25.70

$20.60

$5.10

$0

$2.70

$1.30

$0

$1.40

Business_Combinations_Textuals

Business Combinations, Textuals (Details) (USD $)

12 Months Ended

12 Months Ended

0 Months Ended

12 Months Ended

0 Months Ended

0 Months Ended

0 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 14, 2012

Dec. 31, 2012

Dec. 13, 2012

Dec. 14, 2012

Feb. 13, 2012

Feb. 13, 2012

Mar. 08, 2012

Mar. 08, 2012

Feb. 09, 2011

Feb. 18, 2011

Acquisition

Acquisition

Acquisition

PSD Segment [Member]

PSD Segment [Member]

PSD Segment [Member]

SSD Segment [Member]

SSD Segment [Member]

SSD Segment [Member]

2013 Acquisitions [Member]

2012 Acquisitions [Member]

2011 Acquisitions [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Contrail [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity Mykonos [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity BitGravity [Member]

Business Acquisition Acquired Entity OpNext [Member]

Business Acquisition Acquired Entity Brilliant [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2012 Acquisitions [Member]

2011 Acquisitions [Member]

2011 Acquisitions [Member]

PSD Segment [Member]

SSD Segment [Member]

SSD Segment [Member]

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Length of time subsequent to acquisition date may result in changes of additional information

'12 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Businesses Acquired

1

3

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Goodwill

$4,057.70

$4,057.80

$3,928.10

$1,616.60

$1,866.30

$1,795.60

$2,441.10

$2,191.50

$2,132.50

$0

$129.70

$0.40

'

'

'

$70.70

'

$58.50

'

$0.50

$0.30

$0.10

Business combination, cash consideration

'

'

'

'

'

'

'

'

'

10

187.3

30.5

'

'

'

'

'

'

'

'

'

'

Intangible assets acquired

'

'

'

'

'

'

'

'

'

9.9

54.1

28.4

17.4

'

'

'

24.3

'

12.4

'

25.7

2.7

Acquired finite-lived intangible asset, weighted average estimated useful life (in years)

'

'

'

'

'

'

'

'

'

'5 years

'

'

'

'

'

'

'6 years

'

'3 years

'

'9 years

'5 years

Business Combination, Acquisition Related Costs

0.9

[1]

2

[1]

9.6

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Business Combination, Step Acquisition, Equity Interest in Acquiree, Percentage

'

'

'

'

'

'

'

'

'

'

'

'

12.00%

'

'

'

'

'

'

'

'

'

Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

'

'

'

'

Business combination, consideration transferred

'

'

'

'

'

'

'

'

'

10

187.3

30.5

91.7

'

'

'

'

'

'

'

'

'

Net tangible assets acquired

'

'

'

'

'

'

'

'

'

0.1

3.5

1.7

'

'

'

'

'

'

'

'

'

'

Business Combination, Recognized Identifiable Tangible Assets Acquired and Liabilities Assumed, Net

'

'

'

'

'

'

'

'

'

'

'

'

3.6

'

'

'

0.2

'

0.1

'

'

1.7

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents

'

'

'

'

'

'

'

'

'

'

'

'

8.6

'

'

'

'

'

'

'

'

'

Privately-held investments

57.2

32

'

'

'

'

'

'

'

'

'

'

'

'

3

'

'

'

'

'

'

'

Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value

'

'

'

'

'

'

'

'

'

'

'

'

17.7

'

'

'

'

'

'

'

'

'

Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain

'

'

'

'

'

'

'

'

'

'

'

'

'

14.7

'

'

'

'

'

'

'

'

Business Acquisition, Percentage of Voting Interests Acquired

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

100.00%

'

'

'

'

'

Payments to Acquire Businesses, Gross

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$82.60

'

$13

'

$26

$4.50

[1]

Amount includes acquisition-related costs reported in cost of revenues and operating expenses.

Cash_Equivalents_and_Investmen2

Cash Equivalents and Investments - Available for Sale Securities (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	$2,777.80		$2,745.70
Available-for-sale Securities, gross unrealized gain	106.9		3.1
Available-for-sale securities, gross unrealized loss	-2.5		-0.3
Available-for-sale securities, estimated fair value	2,882.20		2,748.50
Trading securities:	'		'
Trading securities, amortized cost	15.4	[1]	12.6	[1]
Trading securities, gross unrealized gain	0	[1]	0	[1]
Trading securities, gross unrealized loss	0	[1]	0	[1]
Trading securities, estimated fair value	15.4	[1]	12.6	[1]
Available-for-sale and Trading Investments [Abstract]	'		'
Total investments, amortized cost	2,793.20		2,758.30
Total investments, gross unrealized gains	106.9		3.1
Total investments, gross unrealized losses	-2.5		-0.3
Total investments, estimated fair value	2,897.60		2,761.10
Cash equivalents [Member]	'		'
Available-for-sale and Trading Investments [Abstract]	'		'
Total investments, amortized cost	996.2		1,225.90
Total investments, gross unrealized gains	0		0
Total investments, gross unrealized losses	0		0
Total investments, estimated fair value	996.2		1,225.90
Restricted investments [Member]	'		'
Available-for-sale and Trading Investments [Abstract]	'		'
Total investments, amortized cost	87.5		105.5
Total investments, gross unrealized gains	0.1		0.1
Total investments, gross unrealized losses	0		0
Total investments, estimated fair value	87.6		105.6
Short-term investments [Member]	'		'
Available-for-sale and Trading Investments [Abstract]	'		'
Total investments, amortized cost	459		441.3
Total investments, gross unrealized gains	104.9		0.3
Total investments, gross unrealized losses	-2		-0.1
Total investments, estimated fair value	561.9		441.5
Long-term investments [Member]	'		'
Available-for-sale and Trading Investments [Abstract]	'		'
Total investments, amortized cost	1,250.50		985.6
Total investments, gross unrealized gains	1.9		2.7
Total investments, gross unrealized losses	-0.5		-0.2
Total investments, estimated fair value	1,251.90		988.1
Fixed Income Securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	1,718.20		1,594.60
Available-for-sale Securities, gross unrealized gain	2.3		3
Available-for-sale securities, gross unrealized loss	-0.6		-0.2
Available-for-sale securities, estimated fair value	1,719.90		1,597.40
Asset-backed securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	249.9		226.2
Available-for-sale Securities, gross unrealized gain	0.1		0.3
Available-for-sale securities, gross unrealized loss	-0.1		-0.1
Available-for-sale securities, estimated fair value	249.9		226.4
Certificates of deposit [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	27.6		42.5
Available-for-sale Securities, gross unrealized gain	0		0
Available-for-sale securities, gross unrealized loss	0		0
Available-for-sale securities, estimated fair value	27.6		42.5
Commercial Paper [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	6.9		22.4
Available-for-sale Securities, gross unrealized gain	0		0
Available-for-sale securities, gross unrealized loss	0		0
Available-for-sale securities, estimated fair value	6.9		22.4
Corporate debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	813.6		533.4
Available-for-sale Securities, gross unrealized gain	2		2.3
Available-for-sale securities, gross unrealized loss	-0.3		-0.1
Available-for-sale securities, estimated fair value	815.3		535.6
Foreign government debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	10.7		5
Available-for-sale Securities, gross unrealized gain	0		0
Available-for-sale securities, gross unrealized loss	0		0
Available-for-sale securities, estimated fair value	10.7		5
Government-sponsored enterprise obligations [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	306.2		270.7
Available-for-sale Securities, gross unrealized gain	0.1		0.3
Available-for-sale securities, gross unrealized loss	-0.1		0
Available-for-sale securities, estimated fair value	306.2		271
US government securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	303.3		494.4
Available-for-sale Securities, gross unrealized gain	0.1		0.1
Available-for-sale securities, gross unrealized loss	-0.1		0
Available-for-sale securities, estimated fair value	303.3		494.5
Publicly-traded equity securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	12		3
Available-for-sale Securities, gross unrealized gain	104.5		0
Available-for-sale securities, gross unrealized loss	-1.9		-0.1
Available-for-sale securities, estimated fair value	114.6		2.9
Money market funds [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	1,043.70		1,145.20
Available-for-sale Securities, gross unrealized gain	0		0
Available-for-sale securities, gross unrealized loss	0		0
Available-for-sale securities, estimated fair value	1,043.70		1,145.20
Mutual funds [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities, amortized cost	3.9		2.9
Available-for-sale Securities, gross unrealized gain	0.1		0.1
Available-for-sale securities, gross unrealized loss	0		0
Available-for-sale securities, estimated fair value	$4		$3
[1]	Balance includes the Company's non-qualified deferred compensation plan assets.

Cash_Equivalents_and_Investmen3

Cash Equivalents and Investments - Maturities of Available for Sale Investments (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Cash Equivalents and Investments [Abstract]	'
Amortized cost due within one year	$467.70
Gross unrealized gains due within one year	0.3
Gross unrealized losses due within one year	0
Estimated fair value due within one year	468
Amortized cost due between one and five years	1,250.50
Gross unrealized gains due between one and five years	2
Gross unrealized losses due between one and five years	-0.6
Estimated fair value due between one and five year	1,251.90
Total investments, amortized cost	1,718.20
Total investments, gross unrealized gains	2.3
Total investments, gross unrealized losses	-0.6
Total investments, estimated fair value	$1,719.90

Cash_Equivalents_and_Investmen4

Cash Equivalents and Investments - Unrealized Loss for Trading and Available for Sale Investments (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	$568.70		$282.50
Unrealized loss, less than 12 months	-2.5		-0.3
Fair value, 12 months or greater	10.3		0.1
Unrealized loss, 12 months or greater	0		0
Total fair value, Available-for-sale investments in continuous unrealized loss position	579		282.6
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-2.5		-0.3
Fixed Income Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	561.9		279.6
Unrealized loss, less than 12 months	-0.6		-0.2
Fair value, 12 months or greater	10.3		0.1
Unrealized loss, 12 months or greater	0		0
Total fair value, Available-for-sale investments in continuous unrealized loss position	572.2		279.7
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-0.6		-0.2
Asset-backed securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	153	[1]	55.1	[2]
Unrealized loss, less than 12 months	-0.1	[1]	-0.1	[2]
Fair value, 12 months or greater	0.6	[1]	0.1	[2]
Unrealized loss, 12 months or greater	0	[1]	0	[2]
Total fair value, Available-for-sale investments in continuous unrealized loss position	153.6	[1]	55.2	[2]
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-0.1	[1]	-0.1	[2]
Certificates of deposit [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		0.3	[3]
Unrealized loss, less than 12 months	'		0	[3]
Fair value, 12 months or greater	'		0	[3]
Unrealized loss, 12 months or greater	'		0	[3]
Total fair value, Available-for-sale investments in continuous unrealized loss position	'		0.3	[3]
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	'		0	[3]
Commercial Paper [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	'		10	[3]
Unrealized loss, less than 12 months	'		0	[3]
Fair value, 12 months or greater	'		0	[3]
Unrealized loss, 12 months or greater	'		0	[3]
Total fair value, Available-for-sale investments in continuous unrealized loss position	'		10	[3]
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	'		0	[3]
Corporate debt securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	156.1	[1]	116
Unrealized loss, less than 12 months	-0.3	[1]	-0.1
Fair value, 12 months or greater	9.7	[1]	0
Unrealized loss, 12 months or greater	0	[1]	0
Total fair value, Available-for-sale investments in continuous unrealized loss position	165.8	[1]	116
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-0.3	[1]	-0.1
Foreign government debt securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	10	[4]	'
Unrealized loss, less than 12 months	0	[4]	'
Fair value, 12 months or greater	0	[4]	'
Unrealized loss, 12 months or greater	0	[4]	'
Total fair value, Available-for-sale investments in continuous unrealized loss position	10	[4]	'
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	0	[4]	'
Government-sponsored enterprise obligations [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	123.1		30	[3]
Unrealized loss, less than 12 months	-0.1		0	[3]
Fair value, 12 months or greater	0		0	[3]
Unrealized loss, 12 months or greater	0		0	[3]
Total fair value, Available-for-sale investments in continuous unrealized loss position	123.1		30	[3]
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-0.1		0	[3]
US government securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	119.7		68.2	[3]
Unrealized loss, less than 12 months	-0.1		0	[3]
Fair value, 12 months or greater	0		0	[3]
Unrealized loss, 12 months or greater	0		0	[3]
Total fair value, Available-for-sale investments in continuous unrealized loss position	119.7		68.2	[3]
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	-0.1		0	[3]
Publicly-traded equity securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Fair value, less than 12 months	6.8		2.9
Unrealized loss, less than 12 months	-1.9		-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	6.8		2.9
Total unrealized loss, Available-for-sale investments in continuous unrealized loss position	($1.90)		($0.10)
[1]	Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of DecemberB 31, 2013.
[2]	Balance greater than 12 months includes investments that were in an immaterial unrealized loss position as of DecemberB 31, 2012.
[3]	Balance for less than 12 months include investments that were in an immaterial unrealized loss position as of DecemberB 31, 2012.
[4]	Balance for less than 12 months include investments that were in an immaterial unrealized loss position as of DecemberB 31, 2013.

Cash_Equivalents_and_Investmen5

Cash Equivalents and Investments - Textuals (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	Investment	Investment
Cash Equivalents and Investments [Abstract]	'	'	'
Total investments In unrealized loss position	178	98	'
Privately-held investments	$57.20	$32	'
Cost Method Investments, Amount Reclassified to Short-term Investments Subsequent to Investee Initial Public Offering	12.2	'	'
Unrealized Gain on Cost Method Investments Recorded Upon Investee Public Offering	102.7	'	'
Other than temporary impairment of privately held equity investments	$2.80	$20	$1.80

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	$2,882.20		$2,748.50
Trading securities:	'		'
Trading securities, estimated fair value	15.4	[1]	12.6	[1]
Fair Value Measurements (Textuals)	'		'
Restricted investments	83.6		102.6
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount	287.4		'
Fair Value, Inputs, Level 1 [Member]	'		'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'		'
Long-term Debt, Fair Value	1,023.50		1,090.70
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	1,374.90		1,692.50
Liabilities measured at fair value:	'		'
Total liabilities 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	1,525.70		1,072.10
Liabilities measured at fair value:	'		'
Total liabilities measured at fair value	-0.7		-0.1
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:	'		'
Total liabilities measured at fair value	0		0
Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Total assets measured at fair value	2,900.60		2,764.60
Liabilities measured at fair value:	'		'
Total liabilities measured at fair value	-0.7		-0.1
Available-for-sale Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	1,359.50		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 measured at fair value on a recurring basis	1,522.70		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 measured at fair value on a recurring basis	0		0
Available-for-sale Securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	2,882.20		2,748.50
Asset-backed securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	249.9		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	249.9		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 measured at fair value on a recurring basis	0		0
Asset-backed securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	249.9		226.4
Certificates of deposit [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	27.6		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	27.6		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 measured at fair value on a recurring basis	0		0
Certificates of deposit [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	27.6		42.5
Commercial Paper [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	6.9		22.4
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	0		0
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	6.9		22.4
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	0		0
Commercial Paper [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	6.9		22.4
Corporate debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	815.3		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	815.3		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 measured at fair value on a recurring basis	0		0
Corporate debt securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	815.3		535.6
Foreign government debt securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	10.7		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	10.7		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 measured at fair value on a recurring basis	0		0
Foreign government debt securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	10.7		5
Government-sponsored enterprise obligations [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	306.2		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	306.2		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 measured at fair value on a recurring basis	0		0
Government-sponsored enterprise obligations [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	306.2		271
Money market funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	1,043.70	[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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	0	[2]	0	[3]
Money market funds [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	1,043.70	[2]	1,145.20	[3]
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	4	[4]	1	[4]
Trading securities:	'		'
Trading securities, estimated fair value	15.4	[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 measured at fair value on a recurring basis	0	[4]	2	[4]
Trading securities:	'		'
Trading securities, estimated fair value	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 measured at fair value on a recurring basis	0	[4]	0	[4]
Trading securities:	'		'
Trading securities, estimated fair value	0	[5]	0	[5]
Mutual funds [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	4	[4]	3	[4]
Trading securities:	'		'
Trading securities, estimated fair value	15.4	[5]	12.6	[5]
US Government Securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	303.3		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 measured at fair value on a recurring basis	197.2		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 measured at fair value on a recurring basis	106.1		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 measured at fair value on a recurring basis	0		0
US Government Securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	303.3		494.5
Publicly-traded equity securities [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	114.6		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 measured at fair value on a recurring basis	114.6		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 measured at fair value on a recurring basis	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 measured at fair value on a recurring basis	0		0
Publicly-traded equity securities [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale securities:	'		'
Available-for-sale securities measured at fair value on a recurring basis	114.6		2.9
Foreign exchange contract [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets measured at fair value on a recurring basis	0		0
Liabilities measured at fair value:	'		'
Derivative liability measured at fair value on a recurring basis	0		0
Foreign exchange contract [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets measured at fair value on a recurring basis	3		3.5
Liabilities measured at fair value:	'		'
Derivative liability measured at fair value on a recurring basis	-0.7		-0.1
Foreign exchange contract [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets measured at fair value on a recurring basis	0		0
Liabilities measured at fair value:	'		'
Derivative liability measured at fair value on a recurring basis	0		0
Foreign exchange contract [Member] | Total Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Derivative assets:	'		'
Derivative assets measured at fair value on a recurring basis	3		3.5
Liabilities measured at fair value:	'		'
Derivative liability measured at fair value on a recurring basis	($0.70)		($0.10)
[1]	Balance includes the Company's non-qualified deferred compensation plan assets.
[2]	Balance includes $83.6 million of restricted investments measured at fair market value, related to the Company's D&O trust and acquisitions 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 the investments measured at fair value related to the Company's non-qualified deferred compensation plan assets.

Fair_Value_Measurements_by_Bal

Fair Value Measurements by Balance Sheet Grouping (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash equivalents measured at fair value	$965.10	$1,048.70
Restricted investments measured at fair value	87.6	103.6
Short-term investments measured at fair value	246.5	224.4
Long-term investments measured at fair value	75.7	315.8
Prepaid expenses and other current assets measured at fair value	0	0
Total assets measured at fair value	1,374.90	1,692.50
Other accrued liabilities measured at fair value	0	0
Total liabilities measured at fair value	0	0
Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash equivalents measured at fair value	31.1	177.2
Restricted investments measured at fair value	0	2
Short-term investments measured at fair value	315.4	217.1
Long-term investments measured at fair value	1,176.20	672.3
Prepaid expenses and other current assets measured at fair value	3	3.5
Total assets measured at fair value	1,525.70	1,072.10
Other accrued liabilities measured at fair value	-0.7	-0.1
Total liabilities measured at fair value	-0.7	-0.1
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
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
Total assets measured at fair value	0	0
Other accrued liabilities measured at fair value	0	0
Total liabilities measured at fair value	0	0
Total Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash equivalents measured at fair value	996.2	1,225.90
Restricted investments measured at fair value	87.6	105.6
Short-term investments measured at fair value	561.9	441.5
Long-term investments measured at fair value	1,251.90	988.1
Prepaid expenses and other current assets measured at fair value	3	3.5
Total assets measured at fair value	2,900.60	2,764.60
Other accrued liabilities measured at fair value	-0.7	-0.1
Total liabilities measured at fair value	($0.70)	($0.10)

Fair_Value_Measurements_Assets

Fair Value Measurements, Assets and Liabilities Measured On A Nonrecurring Basis (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Other than temporary impairment of privately held equity investments	($2.80)	($20)	($1.80)
Fair Value, Measurements, Nonrecurring [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Liability measured at non-recurring basis	0	0	'
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Fair value of intangible asset subsequent to impairment	0	0	'
Impairment of intangible assets (excluding goodwill)	0	-5.4	'
Asset Impairment Charges	-2.8	-25.4	'
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Cost Method Investment, Privately Held Companies [Member]	'	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'	'
Privately-held investments measured on nonrecurring basis	2	0	'
Other than temporary impairment of privately held equity investments	($2.80)	($20)	'

Derivative_Instruments_Details

Derivative Instruments (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivative	$282	$198.60
Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivative	137.6	85.8
Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Notional amount of foreign currency derivative	$144.40	$112.80

Derivative_Instruments_Cash_Fl

Derivative Instruments, Cash Flow Hedges (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]	'	'	'
Maximum Length of Time Hedged in Cash Flow Hedge	'1 year	'	'
Foreign exchange contract [Member] | Cash flow hedging [Member]	'	'	'
Derivatives, Fair Value [Line Items]	'	'	'
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion	$1	'	$7.90
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion	'	7.2	'
Operating expenses [Member] | Foreign exchange contract [Member] | Cash flow hedging [Member]	'	'	'
Derivatives, Fair Value [Line Items]	'	'	'
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion	0.7	'	0.7
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	'	$7.50	'

Derivative_Instruments_NonDesi

Derivative Instruments, Non-Designated Hedges (Details) (Foreign exchange contract [Member], Other (expense) income, net [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Foreign exchange contract [Member] | Other (expense) income, net [Member]	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'
Derivative instruments not designated as hedging instruments, gain (loss), net	$0.90	$1	$1.50

Goodwill_and_Purchased_Intangi2

Goodwill and Purchased Intangible Assets (Details) (USD $)	12 Months Ended							9 Months Ended	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013
				PSD [Member]	PSD [Member]	SSD [Member]	SSD [Member]	Security other [Member]	Business Acquisition Acquired Entity Contrail [Member]
								PSD [Member]	PSD [Member]
Goodwill [Roll Forward]	'	'	'	'	'	'	'	'	'
Goodwill, beginning of period	$4,057,800,000	$3,928,100,000	'	$1,866,300,000	$1,795,600,000	$2,191,500,000	$2,132,500,000	'	'
Additions due to business combinations	'	130,300,000	'	'	70,700,000	'	59,600,000	'	'
Adjustments to goodwill	'	-600,000	'	'	0	'	-600,000	'	'
Reclassifications	0	'	'	-249,600,000	'	249,600,000	'	179,000,000	70,600,000
Foreign currency translation adjustment	-100,000	'	'	-100,000	'	0	'	'	'
Goodwill, end of period	4,057,700,000	4,057,800,000	3,928,100,000	1,616,600,000	1,866,300,000	2,441,100,000	2,191,500,000	'	'
Impairments to goodwill	$0	$0	$0	'	'	'	'	'	'

Goodwill_and_Purchased_Intangi3

Goodwill and Purchased Intangible Assets, Finite Lived Intangible Assets by Class (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Purchased Intangible Assets [Line Items]	'	'	'
Finite-Lived Intangible Assets, Gross	'	$628.40	'
Finite-Lived Intangible Assets, Accumulated Amortization	'	-484.2	'
Finite-Lived Intangible Assets, Accumulated Impairment and Other Charges	'	32.7	'
Finite-Lived Intangible Assets, Net	106.9	111.5	'
Total purchased intangible assets, gross	655.7	645.8	'
Total purchased intangible assets, accumulated amortization	-516.1	-484.2	'
Accumulated intangible asset impairment and other charges	-32.7	-32.7	'
Total purchased intangible assets, net	106.9	128.9	'
Amortization of Intangible Assets	31.9	32.3	27.1
Carrying value of intangible assets	5.4	'	'
Intangible assets no longer utilized	10.7	'	'
Impairment of intangible assets	16.1	'	'
In Process Research and Development [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Indefinite-Lived Intangible Assets	'	17.4	'
Indefinite-Lived Intangible Assets, Accumulated impairment and Other Charges	'	0	'
Technologies and patents [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Finite-Lived Intangible Assets, Gross	581.4	554.1	'
Finite-Lived Intangible Assets, Accumulated Amortization	-453.4	-425	'
Finite-Lived Intangible Assets, Accumulated Impairment and Other Charges	30.5	30.5	'
Finite-Lived Intangible Assets, Net	97.5	98.6	'
Customer Contracts, Support Agreements, and Related Relationships [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Finite-Lived Intangible Assets, Gross	74.3	'	'
Finite-Lived Intangible Assets, Accumulated Amortization	-62.7	'	'
Finite-Lived Intangible Assets, Accumulated Impairment and Other Charges	2.2	'	'
Finite-Lived Intangible Assets, Net	9.4	'	'
Customer contracts, support agreements, and related relationships [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Finite-Lived Intangible Assets, Gross	'	74.3	'
Finite-Lived Intangible Assets, Accumulated Amortization	'	-59.2	'
Finite-Lived Intangible Assets, Accumulated Impairment and Other Charges	'	2.2	'
Finite-Lived Intangible Assets, Net	'	12.9	'
Cost of revenues [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Amortization of Intangible Assets	27.3	27.6	21.7
Selling and marketing [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Amortization of Intangible Assets	3.4	3.5	4.1
General and administrative [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Amortization of Intangible Assets	1.2	1.2	1.3
Operating expenses [Member]	'	'	'
Purchased Intangible Assets [Line Items]	'	'	'
Amortization of Intangible Assets	$4.60	$4.70	$5.40

Goodwill_and_Purchased_Intangi4

Goodwill and Purchased Intangible Assets, Estimated Future Amortization Expense Intangible Assets (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'	'
2014	$36.20	'
2015	32.6	'
2016	18.5	'
2017	10.5	'
2018	3.7	'
Thereafter	5.4	'
Finite-Lived Intangible Assets, Net	$106.90	$111.50

Other_Financial_Information_In

Other Financial Information, Inventories (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2013
Schedule of Inventory [Line Items]	'	'
Production materials	$53.10	$51.30
Finished goods	4.1	1.4
Total inventories, net	57.2	52.7
Inventory held in excess of forecasted demand	44.3	'
Restructuring Plan 2012 [Member]	'	'
Schedule of Inventory [Line Items]	'	'
Inventory held in excess of forecasted demand	$36.30	'

Other_Financial_Information_Pr

Other Financial Information, Property and Equipment (Details) (USD $)

12 Months Ended

3 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Computers and equipment [Member]

Computers and equipment [Member]

Software [Member]

Software [Member]

Leasehold improvements [Member]

Leasehold improvements [Member]

Furniture and fixtures [Member]

Furniture and fixtures [Member]

Building and building Improvements [Member]

Building and building Improvements [Member]

Land and land improvements [Member]

Land and land improvements [Member]

Restructuring Plan 2011 [Member]

Property and Equipment [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, gross

$1,709.10

$1,580.60

'

$794.60

$711.80

$108.40

$106.60

$202.60

$206.50

$42.50

$28.70

$242.60

$206.10

$238.90

$208.20

'

Construction-in-process, gross

79.5

112.7

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accumulated depreciation

-826.8

-768.7

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, net

882.3

811.9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation expense

148.2

154.7

142.2

'

'

'

'

'

'

'

'

'

'

'

'

'

Asset impairment charge in restructuring and other charges

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$13.50

Other_Financial_Information_Ot

Other Financial Information, Other Long-Term Assets (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other Financial Information [Abstract]	'	'
Privately-held investments	$57.20	$32
Licensed software	90.4	84.4
Federal income tax receivable	20	0
Financed customer receivable	19.9	0
Inventory	15.2	0
Prepaid costs, deposits, and other	31.1	21.9
Other long-term assets	$233.80	$138.30

Other_Financial_Information_Wa

Other Financial Information, Warranties (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Warranty Reserve [Roll Forward]	'	'
Beginning balance	$29.70	$28.30
Provisions made during the period, net	28.8	31.9
Change in estimate	-2.1	0
Actual costs incurred during the period	-28.4	-30.5
Ending balance	$28	$29.70

Other_Financial_Information_De

Other Financial Information, Deferred Revenue (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Deferred Revenue [Abstract]	'	'
Deferred revenue, net	$1,069.30	$923.40
Deferred Revenue Reported as [Abstract]	'	'
Deferred revenue, current	705.8	693.5
Deferred revenue, long-term	363.5	229.9
Deferred product revenue [Member]	'	'
Deferred Revenue [Abstract]	'	'
Undelivered product commitments and other product deferrals	184.9	256.9
Distributor inventory and other sell-through items	118.7	138.4
Deferred gross product revenue	303.6	395.3
Deferred cost of product revenue	-58.6	-99.4
Deferred revenue, net	245	295.9
Deferred service revenue [Member]	'	'
Deferred Revenue [Abstract]	'	'
Deferred revenue, net	$824.30	$627.50

Other_Financial_Information_Ot1

Other Financial Information, Other Expense, Net (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Interest income

'

'

'

'

'

'

'

'

$8.70

$11

$9.70

Interest expense

'

'

'

'

'

'

'

'

-58.4

-52.9

-49.5

Other

'

'

'

'

'

'

'

'

9.3

25.3

-7

Other expense, net

-10.2

-7.5

-12.6

-10.1

9

-4

[1]

2.8

-24.4

-40.4

-16.6

-46.8

Cost-method investments, realized gains (loss)

'

'

'

'

'

'

'

'

7.1

45.5

'

Other than temporary impairment of privately held equity investments

'

'

'

'

'

'

'

'

2.8

20

1.8

Interest expense, long-term debt

'

'

'

'

'

'

'

'

45.2

40

37.7

Capitalized interest

'

'

'

'

'

'

'

'

1.9

7.1

1.2

Legal fees

'

'

'

'

'

'

'

'

7

'

'

2012 Acquisitions [Member] | Business Acquisition Acquired Entity Contrail [Member]

'

'

'

'

'

'

'

'

'

'

'

Business Acquisition [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Cost method investments, gain on acquisition

'

'

'

'

'

'

'

'

'

$14.70

'

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

Restructuring_and_Other_Charge2

Restructuring and Other Charges (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restructuring Reserve [Roll Forward]	'	'	'
31-Dec-12	$18.20	'	'
Charges	47.5	99.7	30.6
Cash Payments	-43.1	'	'
Non-cash Settlements and Other	-4.8	'	'
31-Dec-13	17.8	18.2	'
Restructuring Plan 2013 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	28.3	'	'
Restructuring Plan 2012 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	112.6	'	'
Restructuring Reserve [Roll Forward]	'	'	'
Charges	19.3	'	'
Severance [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
31-Dec-12	10.6	'	'
Charges	22.9	36.7	15.3
Cash Payments	-27.8	'	'
Non-cash Settlements and Other	-0.1	'	'
31-Dec-13	5.6	10.6	'
Severance [Member] | Restructuring Plan 2013 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	18.3	'	'
Severance [Member] | Restructuring Plan 2011 [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
Charges	-0.1	'	'
Facilities [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
31-Dec-12	5.2	'	'
Charges	10	5.8	0.2
Cash Payments	-6	'	'
Non-cash Settlements and Other	-4.1	'	'
31-Dec-13	5.1	5.2	'
Contract terminations and other [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
31-Dec-12	2.4	'	'
Charges	14.6	57.2	15.1
Cash Payments	-9.3	'	'
Non-cash Settlements and Other	-0.6	'	'
31-Dec-13	7.1	2.4	'
Contract terminations and other [Member] | Restructuring Plan 2013 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	10	'	'
Cost of revenues [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
Charges	8.4	52.9	0
Cost of revenues [Member] | Restructuring Plan 2013 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	3.3	'	'
Cost of revenues [Member] | Restructuring Plan 2012 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	58	'	'
Restructuring and other charges [Member]	'	'	'
Restructuring Reserve [Roll Forward]	'	'	'
Charges	39.1	46.8	30.6
Restructuring and other charges [Member] | Restructuring Plan 2013 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	25	'	'
Restructuring and other charges [Member] | Restructuring Plan 2012 [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring cost incurred to date	54.6	'	'
Maximum [Member] | Severance [Member]	'	'	'
Restructuring Reserve [Line Items]	'	'	'
Restructuring expected cost	$2	'	'

LongTerm_Debt_and_Financing_De

Long-Term Debt and Financing (Details) (USD $)	12 Months Ended					12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Mar. 31, 2011	Dec. 31, 2013	Mar. 31, 2011	Dec. 31, 2013	Mar. 31, 2011	Dec. 31, 2013
				Fixed Rate Note Due 2016 [Member]	Fixed Rate Note Due 2016 [Member]	Fixed Rate Note Due 2021 [Member]	Fixed Rate Note Due 2021 [Member]	Fixed Rate Note Due 2041 [Member]	Fixed Rate Note Due 2041 [Member]	Financing guarantee with recourse [Member]
Long-Term Debt [Line Items]	'	'	'	'	'	'	'	'	'	'
Debt Instrument, Maturity Date	'	'	'	15-Mar-16	'	15-Mar-21	'	15-Mar-41	'	'
Debt Instrument, Interest Rate, Stated Percentage	'	'	'	3.10%	'	4.60%	'	5.95%	'	'
Change of Control Repurchase Price Percentage	101.00%	'	'	'	'	'	'	'	'	'
Long-term Debt, Gross	$1,000,000,000	'	'	$300,000,000	$300,000,000	$300,000,000	$300,000,000	$400,000,000	$400,000,000	'
Unaccreted Discount	-700,000	'	'	'	'	'	'	'	'	'
Long-term debt	999,300,000	999,200,000	'	'	'	'	'	'	'	'
Debt Instrument, Interest Rate, Effective Percentage	'	'	'	3.12%	'	4.63%	'	6.01%	'	'
Financing Arrangements [Abstract]	'	'	'	'	'	'	'	'	'	'
Number of days due from receivable	'30 days	'	'	'	'	'	'	'	'	'
Sale of receivables	898,400,000	677,800,000	738,200,000	'	'	'	'	'	'	'
Proceeds from sale and collection of receivables	843,900,000	679,800,000	686,500,000	'	'	'	'	'	'	'
Receivables from sale of receivables	189,800,000	147,600,000	'	'	'	'	'	'	'	'
Guarantor obligations, current carrying value	'	'	'	'	'	'	'	'	'	30,200,000
Cash received from financing provider that has not been recognized as revenue	$62,300,000	$30,700,000	'	'	'	'	'	'	'	'

Equity_Stock_Repurchase_Activi

Equity, Stock Repurchase Activities (Details) (USD $)	1 Months Ended	12 Months Ended			1 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Jul. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 28, 2010	Jun. 30, 2012
					2010 Stock Repurchase Program [Member]	2012 Stock Repurchase Program [Member]
Stock repurchase program, authorized amount	$1,000,000,000	'	'	'	$1,000,000,000	$1,000,000,000
Stock repurchase program, remaining authorized repurchase amount	'	997,700,000	'	'	'	'
Repurchases under stock repurchase programs, shares repurchased	'	28.9	35.8	17.5	'	'
Repurchases under stock repurchase programs, average price per share	'	$19.76	$18.05	$30.93	'	'
Repurchases under stock repurchase programs, amount repurchased	'	570,600,000	645,600,000	541,200,000	'	'
Repurchases for tax withholding, shares repurchased	'	0.4	0.2	0.2	'	'
Repurchases for tax withholding, average price per share	'	$20.23	$23.40	$35.98	'	'
Repurchases for tax withholding, amount repurchased	'	$7,200,000	$5,000,000	$7,400,000	'	'

Equity_Equity_Accumulated_Othe

Equity Equity, Accumulated Other Comprehensive Income, Net of Tax (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

'

'

'

$4.70

'

'

'

($17.60)

$4.70

($17.60)

'

Other comprehensive gain (loss) before reclassifications

'

'

'

'

'

'

'

'

62.4

17

'

Amount reclassified from accumulated other comprehensive income

'

'

'

'

'

'

'

'

-2.5

5.3

'

Other comprehensive gain (loss)

'

'

'

'

'

'

'

'

59.9

22.3

-16.3

Ending Balance

64.6

'

'

'

4.7

'

'

'

64.6

4.7

-17.6

Other expense

-10.2

-7.5

-12.6

-10.1

9

-4

[1]

2.8

-24.4

-40.4

-16.6

-46.8

Cost of revenues

470

[2]

439.1

[2]

430.2

[2]

388.4

[2]

407.8

[3]

444.5

[1],[3]

405.9

[3]

398.4

[3]

1,727.70

1,656.60

1,580.10

Selling and marketing expense

283.2

[4]

269.5

[4]

267.1

[4]

256.1

[4]

264.7

[4]

261.8

[1],[4]

260.4

[4]

258.6

[4]

1,075.90

1,045.50

1,005.20

Research and development expense

258.7

[5]

264.6

[5]

257.7

[5]

262.2

[5]

275.1

288.2

[1]

268.7

269.6

1,043.20

1,101.60

1,026.80

General and administrative expense

48.2

[4]

61.4

[4]

49.2

[4]

58.5

[4]

51.7

[4]

50

[1],[4]

48.9

[4]

56.2

[4]

217.3

206.8

187.5

Unrealized Gains (Losses) on Available-for- Sale Securities [Member]

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

'

'

'

2.1

[6]

'

'

'

0.1

[6]

2.1

[6]

0.1

[6]

'

Other comprehensive gain (loss) before reclassifications

'

'

'

'

'

'

'

'

65.1

[6]

3.2

[6]

'

Amount reclassified from accumulated other comprehensive income

'

'

'

'

'

'

'

'

-1

[6]

-1.2

[6]

'

Other comprehensive gain (loss)

'

'

'

'

'

'

'

'

64.1

[6]

2

[6]

'

Ending Balance

66.2

[6]

'

'

'

2.1

[6]

'

'

'

66.2

[6]

2.1

[6]

'

Other expense

'

'

'

'

'

'

'

'

1

1.2

'

Unrealized Gains (Losses) on Cash Flow Hedges [Member]

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

'

'

'

3

[7]

'

'

'

-10.9

[7]

3

[7]

-10.9

[7]

'

Other comprehensive gain (loss) before reclassifications

'

'

'

'

'

'

'

'

0.7

[7]

7.4

[7]

'

Amount reclassified from accumulated other comprehensive income

'

'

'

'

'

'

'

'

-1.5

[7]

6.5

[7]

'

Other comprehensive gain (loss)

'

'

'

'

'

'

'

'

-0.8

[7]

13.9

'

Ending Balance

2.2

[7]

'

'

'

3

[7]

'

'

'

2.2

[7]

3

[7]

'

Cost of revenues

'

'

'

'

'

'

'

'

1.1

0.9

'

Selling and marketing expense

'

'

'

'

'

'

'

'

4.3

2

'

Research and development expense

'

'

'

'

'

'

'

'

3.4

2.3

'

General and administrative expense

'

'

'

'

'

'

'

'

0.5

1.3

'

Foreign Currency Translation Adjustments [Member]

'

'

'

'

'

'

'

'

'

'

'

Accumulated Other Comprehensive Income, Net of Tax [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance

'

'

'

-0.4

'

'

'

-6.8

-0.4

-6.8

'

Other comprehensive gain (loss) before reclassifications

'

'

'

'

'

'

'

'

-3.4

6.4

'

Amount reclassified from accumulated other comprehensive income

'

'

'

'

'

'

'

'

0

0

'

Other comprehensive gain (loss)

'

'

'

'

'

'

'

'

-3.4

6.4

'

Ending Balance

($3.80)

'

'

'

($0.40)

'

'

'

($3.80)

($0.40)

'

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

[2]

In the third quarter of 2013, the Company implemented the 2013 Restructuring Plan for workforce reductions, contract terminations, and project cancellations and recorded restructuring charges of $7.4 million and $3.7 million to operating expenses and cost of revenues, respectively. In the fourth quarter of 2013, the Company continued to implement restructuring activities under the 2013 Restructuring Plan and primarily recorded charges to operating expenses of $17.6 million.

[3]

In the third quarter of 2012, the Company implemented the 2012 Restructuring Plan for workforce reductions, facility consolidations or closures, and supply chain and procurement efficiencies and recorded restructuring charges of $29.5 million. In connection with its restructuring activities, the Company also recorded certain inventory and intangible asset impairment charges totaling $52.4 million to cost of revenues. In the fourth quarter of 2012, the Company continued to implement restructuring activities under the 2012 Restructuring Plan.

[4]

Certain amounts in the prior quarters' Condensed Consolidated Statements of Operations have been reclassified to conform to the current year presentation.

[5]

In the second quarter of 2013, the Company extended the useful lives of certainB computers and equipmentB based on actual historical usage,B 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. This change in accounting estimate decreased depreciation expense within research and development expense by approximately $11.0 million or $0.01 per diluted share for the second quarter of 2013, $9.4 million or $0.01 for the third quarter of 2013, and $7.9 million or $0.01 for the fourth quarter of 2013.

[6]

The reclassifications out of accumulated other comprehensive income during the years ended DecemberB 31, 2013 and DecemberB 31, 2012 for realized gains on available-for-sale securities of $1.0 million and $1.2 million, respectively, are included in other expense, net, in the Consolidated Statements of Operations.

[7]

The reclassifications out of accumulated other comprehensive income during the year ended DecemberB 31, 2013 for realized gains on cash flow hedges are included within cost of revenues of $1.1 million and sales and marketing of $4.3 million and for realized losses within research and development of $3.4 million and general and administrative of $0.5 million for which the hedged transactions relate in the Consolidated Statements of Operations. The reclassifications out of accumulated other comprehensive income during the year ended DecemberB 31, 2012 for realized losses on cash flow hedges are included within cost of revenues of $0.9 million, research and development of $2.3 million, sales and marketing of $2.0 million, and general and administrative of $1.3 million for which the hedged transactions relate in the Consolidated Statements of Operations.

Employee_Benefit_Plans_Details

Employee Benefit Plans (Details) (USD $)

12 Months Ended

1 Months Ended

12 Months Ended

12 Months Ended

12 Months Ended

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2012

31-May-11

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

MyKonos and Contrail [Member]

Equity Incentive Plan 2006 [Member]

Equity Incentive Plan 2006 [Member]

Equity Incentive Plan 2006 [Member]

Plan 1996 and 2000 [Member]

Employee Stock Purchase Plan 2008 [Member]

Performance Shares (PSAs) [Member]

Performance Shares (PSAs) [Member]

Performance Shares (PSAs) [Member]

Stock Compensation Plan [Member]

Stock Options [Member]

RSUs and PSAs [Member]

From 2006 [Member]

Prior to 2006 [Member]

Equity Incentive Plan 2006 [Member]

Equity Incentive Plan 2006 [Member]

Stock Options [Member]

Stock Options [Member]

Equity Incentive Plan 2006 [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate Number Of Shares Subject to PSAs Granted

'

'

'

'

'

'

'

'

'

'

1,100,000

900,000

1,900,000

'

'

'

'

'

Share-Based Compensation Plans

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common Stock, Capital Shares Reserved for Future Issuance

'

'

'

'

'

'

'

'

'

19,000,000

'

'

'

103,800,000

'

'

'

'

Number of Shares in Authorized

'

'

'

'

'

'

149,500,000

'

'

'

'

'

'

'

'

'

'

'

Maximum Additional Shares Expire Unexercised, Under 1996 and 2000 Plan

'

'

'

'

'

'

'

'

75,000,000

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized

'

'

'

'

'

30,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Shares, Outstanding

'

'

'

'

'

'

43,800,000

'

'

'

'

'

'

'

'

'

'

'

Number of Shares Available for Future Issuance

'

'

'

'

'

'

49,100,000

57,300,000

'

6,200,000

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period

'

'

'

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'7 years

'10 years

Share-based Compensation Arrangement by Share-based Payment Award, Vest Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'4 years

'

'

'

Shared-based Compensation Arrangement Based Solely on Continuing Employment, Vest Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'3 years

'

'

Shared-based Compensation Arrangement. Other Than Based on Continuing Employment, Vest Period

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'1 year

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Assumed Awards

'

'

'

'

7,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Assumed Awards Exempt from Registration

'

'

'

'

5,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding Stock Options and RSU's from Awards Assumed

4,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price

'

'

'

'

'

'

'

'

'

15.00%

'

'

'

'

'

'

'

'

Periodic Payroll Deduction - Percentage of Base Salary

'

'

'

'

'

'

'

'

'

10.00%

'

'

'

'

'

'

'

'

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

'

'

'

'

'

'

'

'

Stock Option Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance, Number of Shares

34,100,000

38,600,000

49,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Granted, Number of Shares

0

3,100,000

5,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Assumed, Number of Shares

'

900,000

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Canceled, Number of Shares

-1,300,000

-2,800,000

-1,900,000

'

'

'

-1,200,000

[2]

'

'

'

'

'

'

'

'

'

'

'

Options Exercised, Number of Shares

-5,600,000

-3,600,000

-13,900,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Expired, Number of Shares

-4,100,000

-2,100,000

-600,000

'

'

'

-4,100,000

[2]

'

'

'

'

'

'

'

'

'

'

'

Ending Balance, Number of Shares

23,100,000

34,100,000

38,600,000

49,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance, Weighted Average Exercise Price

$24.13

$23.98

$21.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Granted, Weighted Average Exercise Price

$0

$22.81

$37.17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Assumed, Weighted Average Exercise Price

'

$0.57

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Canceled, Weighted Average Exercise Price

$29.56

$26.64

$26.76

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Exercised, Weighted Average Exercise Price

$15.58

$11.71

$21.13

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Options Expired, Weighted Average Exercise Price

$28.35

$26.97

$34.32

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Ending Balance, Weighted Average Exercise Price

$25.15

$24.13

$23.98

$21.90

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Weighted Average Remaining Contractual Term at Period End

'2 years 4 months 24 days

'3 years 1 month 6 days

'3 years 8 months 12 days

'4 years 1 month 6 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate Intrinsic Value at Period End

44,600,000

52,500,000

75,300,000

744,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested or Expected-to-Vest Options, Number of Shares at Period End

22,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested or Expected-to-Vest Options, Weighted Average Exercise Price at Period End

$25.24

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested and Expected-to-Vest Options, Weighted Average Remaining Contractual Term at Period End

'2 years 4 months 24 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Vested or Expected-to-Vest Options, Aggregate Intrinsic Value at Period End

42,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercisable Options, Number of Shares at Period End

20,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercisable Options, Weighted Average Exercise Price at Period End

$25.40

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercisable Options, Weighted Average Remaining Contractual Term at Period End

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercisable Options, Aggregate Intrinsic Value at Period End

30,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share Price

$22.57

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value

29,400,000

27,900,000

249,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Fair Value of Options Vested

45,200,000

70,900,000

80,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum shares to be Issued on achievement of performance goals in respect of PSAs

'

'

'

'

'

'

'

'

'

'

0

0

0

'

'

'

'

'

Maximum shares to be issued on achievement of performance goals in respect of PSAs

'

'

'

'

'

'

'

'

'

'

2,200,000

2,200,000

4,500,000

'

'

'

'

'

Equity Instruments Other than Options, Vested in Period, Fair Value

$221,500,000

$132,000,000

$57,700,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Stock options assumed in connection with the acquisition of Contrail.

[2]

Includes canceled or expired options under the 1996 Plan and the 2000 Plan that expired after May 18, 2006, which become available for grant under the 2006 Plan according to its terms.

Employee_Benefit_Plans_Options

Employee Benefit Plans, Options Outstanding Exercise Price Range (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Number Outstanding (in number of shares)	23.1	'	'	'
Weighted Average Remaining Contractual Life (in years)	'2 years 4 months 24 days	'	'	'
Weighted Average Exercise (in dollars)	$25.15	$24.13	$23.98	$21.90
Number Exercisable (in number of shares)	20.5	'	'	'
Weighted Average Exercise Price (in dollars)	$25.40	'	'	'
$0.03 - $15.09	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$0.03	'	'	'
Exercise Price Range, Upper Range Limit	$15.09	'	'	'
Number Outstanding (in number of shares)	2.9	'	'	'
Weighted Average Remaining Contractual Life (in years)	'3 years 10 months 24 days	'	'	'
Weighted Average Exercise (in dollars)	$10.89	'	'	'
Number Exercisable (in number of shares)	2.3	'	'	'
Weighted Average Exercise Price (in dollars)	$13.76	'	'	'
$16.00 - $21.12	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$16	'	'	'
Exercise Price Range, Upper Range Limit	$21.12	'	'	'
Number Outstanding (in number of shares)	2.4	'	'	'
Weighted Average Remaining Contractual Life (in years)	'1 year 4 months 24 days	'	'	'
Weighted Average Exercise (in dollars)	$18.41	'	'	'
Number Exercisable (in number of shares)	2.3	'	'	'
Weighted Average Exercise Price (in dollars)	$18.33	'	'	'
$21.43 - $23.84	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$21.43	'	'	'
Exercise Price Range, Upper Range Limit	$23.84	'	'	'
Number Outstanding (in number of shares)	2.4	'	'	'
Weighted Average Remaining Contractual Life (in years)	'2 years 2 months 12 days	'	'	'
Weighted Average Exercise (in dollars)	$22.46	'	'	'
Number Exercisable (in number of shares)	2.1	'	'	'
Weighted Average Exercise Price (in dollars)	$22.60	'	'	'
$23.89 - $24.20	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$23.89	'	'	'
Exercise Price Range, Upper Range Limit	$24.20	'	'	'
Number Outstanding (in number of shares)	2.6	'	'	'
Weighted Average Remaining Contractual Life (in years)	'2 years 3 months 18 days	'	'	'
Weighted Average Exercise (in dollars)	$24.16	'	'	'
Number Exercisable (in number of shares)	2.1	'	'	'
Weighted Average Exercise Price (in dollars)	$24.15	'	'	'
$24.25 - $25.49	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$24.25	'	'	'
Exercise Price Range, Upper Range Limit	$25.49	'	'	'
Number Outstanding (in number of shares)	2.3	'	'	'
Weighted Average Remaining Contractual Life (in years)	'1 year 3 months 18 days	'	'	'
Weighted Average Exercise (in dollars)	$25.07	'	'	'
Number Exercisable (in number of shares)	2.3	'	'	'
Weighted Average Exercise Price (in dollars)	$25.07	'	'	'
$25.50 - $26.90	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$25.50	'	'	'
Exercise Price Range, Upper Range Limit	$26.90	'	'	'
Number Outstanding (in number of shares)	3.2	'	'	'
Weighted Average Remaining Contractual Life (in years)	'1 year 9 months 18 days	'	'	'
Weighted Average Exercise (in dollars)	$26.55	'	'	'
Number Exercisable (in number of shares)	3.2	'	'	'
Weighted Average Exercise Price (in dollars)	$26.55	'	'	'
$26.97 - $29.89	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$26.97	'	'	'
Exercise Price Range, Upper Range Limit	$29.89	'	'	'
Number Outstanding (in number of shares)	3.1	'	'	'
Weighted Average Remaining Contractual Life (in years)	'2 years 7 months 6 days	'	'	'
Weighted Average Exercise (in dollars)	$28.54	'	'	'
Number Exercisable (in number of shares)	2.9	'	'	'
Weighted Average Exercise Price (in dollars)	$28.52	'	'	'
$29.93 - $38.93	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$29.93	'	'	'
Exercise Price Range, Upper Range Limit	$38.93	'	'	'
Number Outstanding (in number of shares)	2.2	'	'	'
Weighted Average Remaining Contractual Life (in years)	'2 years 2 months 12 days	'	'	'
Weighted Average Exercise (in dollars)	$33.31	'	'	'
Number Exercisable (in number of shares)	1.9	'	'	'
Weighted Average Exercise Price (in dollars)	$33.16	'	'	'
$40.26 - $40.26	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$40.26	'	'	'
Exercise Price Range, Upper Range Limit	$40.26	'	'	'
Number Outstanding (in number of shares)	1.1	'	'	'
Weighted Average Remaining Contractual Life (in years)	'4 years	'	'	'
Weighted Average Exercise (in dollars)	$40.26	'	'	'
Number Exercisable (in number of shares)	0.8	'	'	'
Weighted Average Exercise Price (in dollars)	$40.26	'	'	'
$44.00 - $44.00	'	'	'	'
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]	'	'	'	'
Exercise Price Range, Lower Range Limit	$44	'	'	'
Exercise Price Range, Upper Range Limit	$44	'	'	'
Number Outstanding (in number of shares)	0.9	'	'	'
Weighted Average Remaining Contractual Life (in years)	'4 years 1 month 6 days	'	'	'
Weighted Average Exercise (in dollars)	$44	'	'	'
Number Exercisable (in number of shares)	0.6	'	'	'
Weighted Average Exercise Price (in dollars)	$44	'	'	'

Employee_Benefit_Plans_Share_B

Employee Benefit Plans, Share Based Compensation, Equity Instruments Other Than Options (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Employee Stock Purchase Plan	'		'		'		'
Common Stock, Shares, Issued	495,200,000		508,400,000		'		'
Employee Stock Purchase Plan 2008 [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Incremental offering period as approved by the Board	'6 months		'		'		'
Employee Stock Purchase Plan	'		'		'		'
Stock Issued During Period, Shares, Employee Stock Purchase Plans	3,300,000		3,500,000		2,400,000		'
Stock Issued During Period, Average Price Per Share, Employee Stock Purchase Plans	$16.53		$16.26		$21.53		'
Common Stock, Shares, Issued	12,800,000		'		'		'
Number of Shares Available for Future Issuance	6,200,000		'		'		'
Restricted Stock Units (RSUs) [Member]	'		'		'		'
Restricted Stock Units And Performance Share Awards Activities	'		'		'		'
Awards Granted, Number of Shares	10,300,000		9,900,000		7,300,000		'
Awards Assumed, Number of Shares	'		200,000	[1],[2]	'		'
Awards Vested, Number of Shares	-6,100,000		-3,100,000		-1,700,000		'
Awards Canceled, Number of Shares	-3,400,000		-2,900,000		-1,000,000		'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'		'		'		'
Awards Granted, Weighted Average Grant-Date Fair Value	$20.32		$20.79		$31.75		'
Awards Assumed, Weighted Average Grant-Date Fair Value	'		$22.21	[1],[2]	'		'
Awards Vested, Weighted Average Grant-Date Fair Value	$26.15		$27.04		$23.26		'
Awards Canceled, Weighted Average Grant-Date Fair Value	$22.99		$27.77		$31.57		'
Restricted Stock Units (RSUs) [Member] | Minimum [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Award vesting period	'3 years		'		'		'
Restricted Stock Units (RSUs) [Member] | Maximum [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Award vesting period	'4 years		'		'		'
Performance Shares (PSAs) [Member]	'		'		'		'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'		'		'		'
Award vesting period	'3 years		'		'		'
Restricted Stock Units And Performance Share Awards Activities	'		'		'		'
Awards Granted, Number of Shares	2,200,000	[3]	2,200,000	[4]	4,500,000	[5]	'
Awards Vested, Number of Shares	-1,100,000		-1,900,000		-800,000		'
Awards Canceled, Number of Shares	-1,700,000		-2,300,000		-2,900,000		'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'		'		'		'
Awards Granted, Weighted Average Grant-Date Fair Value	$21.27	[3]	$23.07	[4]	$38.64	[5]	'
Awards Vested, Weighted Average Grant-Date Fair Value	$28.52		$18.21		$24.76		'
Awards Canceled, Weighted Average Grant-Date Fair Value	$29.10		$29.71		$30.72		'
Aggregate Number Of Shares Subject to PSAs Granted	1,100,000		900,000		1,900,000		'
Minimum shares to be Issued on achievement of performance goals in respect of PSAs	0		0		0		'
Maximum shares to be issued on achievement of performance goals in respect of PSAs	2,200,000		2,200,000		4,500,000		'
RSUs, RSAs, and PSAs [Member]	'		'		'		'
Restricted Stock Units And Performance Share Awards Activities	'		'		'		'
Beginning Balance, Number of Shares	26,800,000		19,600,000		14,200,000		'
Ending Balance, Number of Shares	25,400,000		26,800,000		19,600,000		14,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'		'		'		'
Beginning Balance, Weighted Average Grant-Date Fair Value	$27.76		$30.27		$25.94		'
Ending Balance, Weighted Average Grant-Date Fair Value	$23.44		$27.76		$30.27		$25.94
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	'1 year 1 month 6 days		'1 year 8 months 12 days		'1 year 6 months		'1 year 8 months 12 days
RSUs and PSAs, Aggregate Intrinsic Value at Period End	$573.50		$565		$400.50		$522.90
Vested and Expected-to-Vest RSUs and PSAs, Number of Shares at Period End	20,800,000		'		'		'
Vested and Expected-to-Vest RSUs and PSAs, Weighted Average Grant-Date Fair Value at Period End	$23.77		'		'		'
Vested and Expected-to-Vest RSUs and PSAs, Weighted Average Remaining Contractual Term at Period End	'1 year		'		'		'
Vested and Expected-to-Vest RSUs and PSAs, Aggregate Intrinsic Value at Period End	$469.20		'		'		'
RSA [Member]	'		'		'		'
Restricted Stock Units And Performance Share Awards Activities	'		'		'		'
Awards Assumed, Number of Shares	5,800,000	[2]	'		'		'
Awards Vested, Number of Shares	-1,600,000		-700,000		'		'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]	'		'		'		'
Awards Assumed, Weighted Average Grant-Date Fair Value	$19.59	[2]	'		'		'
Awards Vested, Weighted Average Grant-Date Fair Value	$19.59		$19.59		'		'
[1]	RSUs and RSAs assumed in connection with the acquisition of Contrail.
[2]	RSUs assumed in connection with the acquisition of Mykonos.
[3]	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.
[4]	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 0.9 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.
[5]	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 is estimated at 1.9 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 4.5 million shares.

Employee_Benefit_Plans_Shares_

Employee Benefit Plans, Shares Available For Grant (Details)	12 Months Ended				1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	31-May-11	Dec. 31, 2013
				Restricted Stock Units and Performance Share Awards [Member]	Equity Incentive Plan 2006 [Member]	Equity Incentive Plan 2006 [Member]
Shares Available For Grant	'	'	'	'	'	'
Beginning Balance, Number of Shares	'	'	'	'	'	57.3
Additional Shares Authorized for Issuance, Number of Shares	'	'	'	'	30	'
Awards Granted, Number of Shares	'	'	'	'	'	-26.1	[1]
Options Granted, Number of Shares	0	-3.1	-5.6	'	'	'
Awards Canceled, Number of Shares	'	'	'	'	'	12.6	[1]
Options Canceled, Number of Shares	1.3	2.8	1.9	'	'	1.2	[2]
Options Expired, Number of Shares	4.1	2.1	0.6	'	'	4.1	[2]
Ending Balance, Number of Shares	'	'	'	'	'	49.1
Fair Market Value on Date of Grant For RSUS And PSAS Issued at Discount, Maximum Percentage	'	'	'	100.00%	'	'
Common Stock for Each Share Subject to RSUs and PSAs	2.1	'	'	'	'	'
[1]	RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant under the 2006 Plan are counted against shares authorized under the plan as two and one-tenth shares of common stock for each share subject to such award. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term.
[2]	Includes canceled or expired options under the 1996 Plan and the 2000 Plan that expired after May 18, 2006, which become available for grant under the 2006 Plan according to its terms.

Employee_Benefit_Plans_Assumpt

Employee Benefit Plans, Assumptions and Resulting Estimates of Fair Value (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Options [Member]	'	'	'
Estimates of Fair Value	'	'	'
Volatility	0.00%	45.00%	43.00%
Risk-free interest rate	0.00%	0.70%	1.50%
Expected life (years)	'0 years	'4 years 2 months 12 days	'4 years 1 month 6 days
Dividend yield	0.00%	0.00%	0.00%
Weighted-average fair value per share	$0	$8.47	$13.17
Employee Stock Purchase Plan [Member]	'	'	'
Estimates of Fair Value	'	'	'
Volatility	36.00%	47.00%	41.00%
Risk-free interest rate	0.10%	0.10%	0.20%
Expected life (years)	'6 months	'6 months	'6 months
Dividend yield	0.00%	0.00%	0.00%
Weighted-average fair value per share	$5.54	$5.53	$7.48

Employee_Benefit_Plans_Share_B1

Employee Benefit Plans, Share Based Compensation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	$244.60	$243.40	$222.20
Stock Options [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	31.5	58.9	76.2
Unrecognized Compensation Cost	33.6	'	'
Weighted Average Period that Unrecognized Compensation Cost Will be Recognized (in years)	'1 year 9 months 18 days	'	'
Restricted Stock Units and Performance Share Awards [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	196.8	163.7	127.5
Unrecognized Compensation Cost	279.1	'	'
Weighted Average Period that Unrecognized Compensation Cost Will be Recognized (in years)	'1 year 9 months 18 days	'	'
Employee Stock Purchase Plan [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	16.3	20.8	18.5
Cost of Revenues, Product [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	4.7	4.6	4.6
Cost of Revenues, Service [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	15.4	17	15.7
Research and Development Expense [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	127.6	109.1	97.7
Selling and Marketing Expense [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	70.9	81.6	70.9
General and Administrative Expense [Member]	'	'	'
Stock Based Compensation Expense Recorded in Cost and Expense Categories	'	'	'
Share-Based Compensation Expense	$26	$31.10	$33.30

Employee_Benefit_Plans_401k_pl

Employee Benefit Plans, 401(k) plan and Deferred Compensation Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Benefit Textuals [Abstract]	'	'	'
Employee Contribution Matched in Percent	30.00%	'	'
Matching Contributions to Plan	$20.70	$20.20	$16.30
NQDC [Member]	'	'	'
Employee Benefit Textuals [Abstract]	'	'	'
Deferred Compensation Liability	$15.40	$12.60	'

Segments_Details

Segments (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

$1,273.60

$1,185.60

$1,150.70

$1,059.20

$1,140.80

$1,118.30

[1]

$1,073.80

$1,032.50

$4,669.10

$4,365.40

$4,448.70

Segment Operating Income [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Segment contribution margin

'

'

'

'

'

'

'

'

2,019.40

1,750

1,931.20

Corporate unallocated expenses

'

'

'

'

'

'

'

'

-1,123.50

[2]

-1,068.70

[2]

-1,013.90

[2]

Amortization of purchased intangible assets

'

'

'

'

'

'

'

'

-31.9

[3]

-32.3

[3]

-27.1

[3]

Share-based compensation expense

'

'

'

'

'

'

'

'

-244.6

-243.4

-222.2

Share-based payroll tax expense

'

'

'

'

'

'

'

'

-5.1

-1.1

-9.3

Restructuring and other charges

'

'

'

'

'

'

'

'

-47.5

[4]

-99.7

[4]

-30.6

[4]

Acquisition-related charges

'

'

'

'

'

'

'

'

-0.9

[5]

-2

[5]

-9.6

[5]

Other unallocated expense

'

'

'

'

'

'

'

'

0

5.3

0

Operating income

195.4

145

138.5

87

130.9

42.8

[1]

86.7

47.7

565.9

308.1

618.5

Other expense, net

-10.2

-7.5

-12.6

-10.1

9

-4

[1]

2.8

-24.4

-40.4

-16.6

-46.8

Income before income taxes and noncontrolling interest

185.2

137.5

125.9

76.9

139.9

38.8

[1]

89.5

23.3

525.5

291.5

571.7

Depreciation by Segment [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Depreciation expense

'

'

'

'

'

'

'

'

148.2

154.7

142.2

PSD [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

3,678.20

3,270.80

3,306.90

Segment Operating Income [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Segment contribution margin

'

'

'

'

'

'

'

'

1,621

1,276.40

1,426.80

Depreciation by Segment [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Depreciation expense

'

'

'

'

'

'

'

'

117.3

116.9

104.9

PSD Product [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

2,881.60

2,501.60

2,661.90

Routing [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

2,243.60

1,946.80

2,166.10

Switching [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

638

554.8

495.8

PSD Service [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

796.6

769.2

645

SSD [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

990.9

1,094.60

1,141.80

Segment Operating Income [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Segment contribution margin

'

'

'

'

'

'

'

'

398.4

473.6

504.4

Depreciation by Segment [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Depreciation expense

'

'

'

'

'

'

'

'

30.9

37.8

37.3

SSD Product [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

638.3

760.5

816.4

Security [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

564.3

669.9

698.3

Routing [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

74

90.6

118.1

SSD Service [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues [Abstract]

'

'

'

'

'

'

'

'

'

'

'

Net revenues

'

'

'

'

'

'

'

'

$352.60

$334.10

$325.40

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

[2]

Amount includes unallocated costs for global functions such as sales, marketing, and general and administrative.

[3]

Amount includes amortization expense of purchased intangible assets reported in cost of revenues and operating expenses.

[4]

Amount includes restructuring and other charges reported in cost of revenues and operating expenses.

[5]

Amount includes acquisition-related costs reported in cost of revenues and operating expenses.

Segments_Geographical_Details

Segments, Geographical (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

$1,273.60

$1,185.60

$1,150.70

$1,059.20

$1,140.80

$1,118.30

[1]

$1,073.80

$1,032.50

$4,669.10

$4,365.40

$4,448.70

Property and equipment, net

882.3

'

'

'

811.9

'

'

'

882.3

811.9

'

United States [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

'

'

'

'

'

'

'

'

2,381.50

2,067.50

2,015.80

Property and equipment, net

801.3

'

'

'

725.5

'

'

'

801.3

725.5

'

Other Americas [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

'

'

'

'

'

'

'

'

232

218.4

222.2

Americas [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

'

'

'

'

'

'

'

'

2,613.50

2,285.90

2,238

EMEA [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

'

'

'

'

'

'

'

'

1,256.90

1,266.30

1,339.80

Asia Pacific [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Total net revenues

'

'

'

'

'

'

'

'

798.7

813.2

870.9

International [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Property and equipment, net

$81

'

'

'

$86.40

'

'

'

$81

$86.40

'

Verizon [Member] | Sales Revenue, Segment [Member] | Customer Concentration Risk [Member]

'

'

'

'

'

'

'

'

'

'

'

Net Revenues by Geographic Region [Line Items]

'

'

'

'

'

'

'

'

'

'

'

Concentration Risk, Percentage

'

'

'

'

'

'

'

'

'

10.30%

'

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

Income_Taxes_Details

Income Taxes (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Components of income before provision for income taxes and noncontrolling interest

'

'

'

'

'

'

'

'

'

'

'

Domestic

'

'

'

'

'

'

'

'

$248.70

$114.10

$218.40

Foreign

'

'

'

'

'

'

'

'

276.8

177.4

353.3

Income before income taxes and noncontrolling interest

185.2

137.5

125.9

76.9

139.9

38.8

[1]

89.5

23.3

525.5

291.5

571.7

Current provision:

'

'

'

'

'

'

'

'

'

'

'

Federal

'

'

'

'

'

'

'

'

-12.9

94.3

19.5

States

'

'

'

'

'

'

'

'

-5

8.4

0.9

Foreign

'

'

'

'

'

'

'

'

32.5

37.1

47.8

Total current provision

'

'

'

'

'

'

'

'

14.6

139.8

68.2

Deferred provision (benefit):

'

'

'

'

'

'

'

'

'

'

'

Federal

'

'

'

'

'

'

'

'

51.2

-28.8

23

States

'

'

'

'

'

'

'

'

-2.7

-1.5

0.6

Foreign

'

'

'

'

'

'

'

'

22.6

3.5

-3.6

Total deferred provision (benefit)

'

'

'

'

'

'

'

'

71.1

-26.8

20

Income tax benefits attributable to employee stock plan activity

'

'

'

'

'

'

'

'

0

-8

58.5

Total provision for income taxes

33.4

38.4

28

-14.1

44.2

22

[1]

31.8

7

85.7

105

146.7

Income tax reconciliation

'

'

'

'

'

'

'

'

'

'

'

Expected provision at 35% rate

'

'

'

'

'

'

'

'

184

102

200.1

State taxes (benefit), net of federal benefit

'

'

'

'

'

'

'

'

-3.6

2

2

Foreign income at different tax rates

'

'

'

'

'

'

'

'

-37.7

-11.6

-50.4

Research and development credits

'

'

'

'

'

'

'

'

32.5

0.5

21.3

Share-based compensation

'

'

'

'

'

'

'

'

25.6

22.4

16.7

Settlement with tax authorities

'

'

'

'

'

'

'

'

-28.3

0

0

Domestic production activities

'

'

'

'

'

'

'

'

-26.3

0

0

Equity investment gain on acquisition

'

'

'

'

'

'

'

'

0

-5.3

0

Other

'

'

'

'

'

'

'

'

4.5

-4

-0.4

Total provision for income taxes

33.4

38.4

28

-14.1

44.2

22

[1]

31.8

7

85.7

105

146.7

Net income tax benefit related to items unique during current year

'

'

'

'

'

'

'

'

64.2

'

'

Income tax benefit for a multi-year claim related to the U.S. production activities deduction

'

'

'

'

'

'

'

'

19.7

'

'

U.S. federal R&D tax credit resulting from the American Taxpayer Relief Act of 2012

'

'

'

'

'

'

'

'

$16.20

'

'

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

Income_Taxes_Deferred_Taxes_De

Income Taxes, Deferred Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:	'	'
Net operating loss carry-forwards	$1,100,000	$10,000,000
Foreign tax credit carry-forwards	63,400,000	58,000,000
Research and other credit carry-forwards	106,600,000	95,300,000
Deferred revenue	71,000,000	98,600,000
Stock-based compensation	86,100,000	97,500,000
Reserves and accruals not currently deductible	153,900,000	175,200,000
Other	13,700,000	13,600,000
Total deferred tax assets	495,800,000	548,200,000
Valuation allowance	-155,700,000	-141,000,000
Deferred tax assets, net of valuation allowance	340,100,000	407,200,000
Deferred tax liabilities:	'	'
Property and equipment basis differences	-3,100,000	-1,000,000
Purchased intangibles	-10,100,000	-40,800,000
Unremitted foreign earnings	-258,900,000	-229,100,000
Deferred compensation and other	-38,700,000	0
Other	-400,000	-1,200,000
Total deferred tax liabilities	311,200,000	272,100,000
Net deferred tax assets	28,900,000	135,100,000
Current deferred tax assets	79,800,000	172,600,000
Current deferred tax liabilities	0	0
Long-term deferred tax assets	2,400,000	0
Long-term deferred tax liabilities	-53,300,000	-37,500,000
Valuation Allowance, Amount	155,700,000	141,000,000
Change in DTA valuation allowance	14,700,000	4,200,000
Cumulative undistributed earnings of certain foreign subsidiaries	1,500,000,000	'
Federal [Member]	'	'
Deferred tax liabilities:	'	'
Net operating loss carry-forwards	1,200,000	'
California [Member]	'	'
Deferred tax liabilities:	'	'
Net operating loss carry-forwards	40,600,000	'
Tax credit carry-forwards	208,100,000	'
Tax credit carry-forward to be credited to APIC when realized	20,100,000	'
California Deferred Tax Assets [Member]	'	'
Deferred tax assets:	'	'
Valuation allowance	-109,200,000	'
Deferred tax liabilities:	'	'
Valuation Allowance, Amount	109,200,000	'
Massachusetts Deferred Tax Assets [Member]	'	'
Deferred tax assets:	'	'
Valuation allowance	-9,700,000	'
Deferred tax liabilities:	'	'
Valuation Allowance, Amount	9,700,000	'
Capital Loss Carryforward [Member]	'	'
Deferred tax assets:	'	'
Valuation allowance	-36,800,000	'
Deferred tax liabilities:	'	'
Valuation Allowance, Amount	$36,800,000	'

Income_Taxes_Income_Tax_Contin

Income Taxes, Income Tax Contingencies (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Dec. 31, 2009	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
					Maximum [Member]	India Tax Authority [Member]	Other Long Term Liabilities [Member]	Other Long Term Liabilities [Member]	Other Long Term Liabilities [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]	'	'	'	'	'	'	'	'	'
Unrecognized Tax Benefits	'	$136.10	$132.20	$116.40	'	'	'	'	'
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	'	15.8	8.8	17.6	'	'	'	'	'
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	'	22.6	0.9	6.4	'	'	'	'	'
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions	'	-2.2	0	0	'	'	'	'	'
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities	'	-31.1	-1.2	-5.4	'	'	'	'	'
Unrecognized Tax Benefits, Reductions Resulting from Lapse of Applicable Statute of Limitations	'	-3.6	-4.6	-2.8	'	'	'	'	'
Unrecognized Tax Benefits	132.2	137.6	136.1	132.2	'	'	'	'	'
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	'	128.8	'	'	'	'	'	'	'
Interest and penalties accrued related to unrecognized tax benefits	'	'	'	'	'	'	18.4	16.7	17.3
Tax expense (benefit) recognized for net interest and penalties in the Consolidated Statements of Operations	'	0.6	-0.6	-1.6	'	'	'	'	'
Possible decrease in gross unrecognized tax benefits within next 12 months	'	'	'	'	1.6	'	'	'	'
Settlement including interest with the IRS related to intercompany R&D cost sharing arrangement	'	19.6	'	'	'	'	'	'	'
Tax benefit recorded from settlement with tax authority	7	'	'	'	'	'	'	'	'
Penalties and interest accrued related to investigation of 2004 to 2008 tax return by India tax authorities	'	'	'	'	'	$4.60	'	'	'

Net_Income_per_Share_Details

Net Income per Share (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Numerator:

'

'

'

'

'

'

'

'

'

'

'

Net income attributable to Juniper Networks

$151.80

$99.10

$97.90

$91

$95.70

$16.80

[1]

$57.70

$16.30

$439.80

$186.50

$425.10

Denominator:

'

'

'

'

'

'

'

'

'

'

'

Weighted-average shares used to compute basic net income per share

'

'

'

'

'

'

'

'

501.8

520.9

529.8

Dilutive effect of employee stock awards

'

'

'

'

'

'

'

'

8.5

5.3

11.6

Weighted-average shares used to compute diluted net income per share

'

'

'

'

'

'

'

'

510.3

526.2

541.4

Net income per share attributable to Juniper Networks common stockholders:

'

'

'

'

'

'

'

'

'

'

'

Basic (in dollars per share)

$0.30

[2]

$0.20

[2]

$0.19

[2]

$0.18

[2]

$0.19

[2]

$0.03

[1],[2]

$0.11

[2]

$0.03

[2]

$0.88

$0.36

$0.80

Diluted (in dollars per share)

$0.30

[2]

$0.19

[2]

$0.19

[2]

$0.18

[2]

$0.19

[2]

$0.03

[1],[2]

$0.11

[2]

$0.03

[2]

$0.86

$0.35

$0.79

Net Income per Share Textuals

'

'

'

'

'

'

'

'

'

'

'

Anti-dilutive shares excluded from computation of diluted earnings per share

'

'

'

'

'

'

'

'

13.2

32.3

17.4

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

[2]

Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.

Commitments_and_Contingencies_2

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013	Mar. 31, 2011	Dec. 31, 2013	Mar. 31, 2011	Dec. 31, 2013	Mar. 31, 2011
				Fixed Rate Note Due 2016 [Member]	Fixed Rate Note Due 2016 [Member]	Fixed Rate Note Due 2021 [Member]	Fixed Rate Note Due 2021 [Member]	Fixed Rate Note Due 2041 [Member]	Fixed Rate Note Due 2041 [Member]
Purchase Commitment, Excluding Long-term Commitment [Line Items]	'	'	'	'	'	'	'	'	'
2014	$49,400,000	'	'	'	'	'	'	'	'
2015	38,400,000	'	'	'	'	'	'	'	'
2016	31,100,000	'	'	'	'	'	'	'	'
2017	26,800,000	'	'	'	'	'	'	'	'
2018	22,600,000	'	'	'	'	'	'	'	'
Thereafter	56,900,000	'	'	'	'	'	'	'	'
Operating leases	225,200,000	'	'	'	'	'	'	'	'
Rent expense	52,800,000	63,200,000	65,700,000	'	'	'	'	'	'
Purchase commitments	491,400,000	'	'	'	'	'	'	'	'
Accrual for estimated carrying charges or obsolete materials charges	22,900,000	'	'	'	'	'	'	'	'
Long-term debt	999,300,000	999,200,000	'	'	'	'	'	'	'
Long-term Debt, Gross	1,000,000,000	'	'	300,000,000	300,000,000	300,000,000	300,000,000	400,000,000	400,000,000
Debt Instrument, Interest Rate, Stated Percentage	'	'	'	3.10%	'	4.60%	'	5.95%	'
Indemnity-related and service-related escrows	89,500,000	'	'	'	'	'	'	'	'
Campus build-out commitments	13,100,000	'	'	'	'	'	'	'	'
Other Contractual Obligations	$10,300,000	'	'	'	'	'	'	'	'

Commitments_and_Contingencies_3

Commitments and Contingencies, Guarantees (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financing guarantee with recourse [Member]	'	'
Guarantor Obligations [Line Items]	'	'
Guarantor obligations, current carrying value	$30.20	'
Financing guarantees, bank guarantees, and standby letters of credit [Member]	'	'
Guarantor Obligations [Line Items]	'	'
Guarantor obligations, current carrying value	$40.10	$12.60

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Unaudited) (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, except Per Share data, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Net revenues:

'

'

'

'

'

'

'

'

'

'

'

Product

$973.50

$900.80

$863.80

$781.80

$847.30

$838.20

[1]

$804.70

$771.90

$3,519.90

$3,262.10

$3,478.30

Service

300.1

284.8

286.9

277.4

293.5

280.1

[1]

269.1

260.6

1,149.20

1,103.30

970.4

Total net revenues

1,273.60

1,185.60

1,150.70

1,059.20

1,140.80

1,118.30

[1]

1,073.80

1,032.50

4,669.10

4,365.40

4,448.70

Cost of revenues:

'

'

'

'

'

'

'

'

'

'

'

Product

351.6

325.5

321.3

278.2

296.1

334.7

[1]

292.6

280.6

1,276.60

1,204

1,155.30

Service

118.4

113.6

108.9

110.2

111.7

109.8

[1]

113.3

117.8

451.1

452.6

424.8

Total cost of revenues

470

[2]

439.1

[2]

430.2

[2]

388.4

[2]

407.8

[3]

444.5

[1],[3]

405.9

[3]

398.4

[3]

1,727.70

1,656.60

1,580.10

Gross margin

803.6

746.5

720.5

670.8

733

673.8

[1]

667.9

634.1

2,941.40

2,708.80

2,868.60

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Research and development

258.7

[4]

264.6

[4]

257.7

[4]

262.2

[4]

275.1

288.2

[1]

268.7

269.6

1,043.20

1,101.60

1,026.80

Sales and marketing

283.2

[5]

269.5

[5]

267.1

[5]

256.1

[5]

264.7

[5]

261.8

[1],[5]

260.4

[5]

258.6

[5]

1,075.90

1,045.50

1,005.20

General and administrative

48.2

[5]

61.4

[5]

49.2

[5]

58.5

[5]

51.7

[5]

50

[1],[5]

48.9

[5]

56.2

[5]

217.3

206.8

187.5

Amortization of purchased intangibles

'

'

'

'

'

'

'

'

31.9

32.3

27.1

Restructuring and other charges

18.1

[2]

6

[2]

8

[2]

7

[2]

10.6

[3]

31

[1],[3]

3.2

[3]

2

[3]

'

'

'

Total operating expenses

608.2

601.5

582

583.8

602.1

631

[1]

581.2

586.4

2,375.50

2,400.70

2,250.10

Operating income

195.4

145

138.5

87

130.9

42.8

[1]

86.7

47.7

565.9

308.1

618.5

Other expense, net

-10.2

-7.5

-12.6

-10.1

9

-4

[1]

2.8

-24.4

-40.4

-16.6

-46.8

Income before income taxes and noncontrolling interest

185.2

137.5

125.9

76.9

139.9

38.8

[1]

89.5

23.3

525.5

291.5

571.7

Income tax provision

33.4

38.4

28

-14.1

44.2

22

[1]

31.8

7

85.7

105

146.7

Consolidated net income

'

'

'

'

'

'

'

'

439.8

186.5

425

Adjust for net loss attributable to noncontrolling interest

'

'

'

'

'

'

'

'

0

0

0.1

Net income attributable to Juniper Networks

151.8

99.1

97.9

91

95.7

16.8

[1]

57.7

16.3

439.8

186.5

425.1

Net income per share attributable to Juniper Networks common stockholders:

'

'

'

'

'

'

'

'

'

'

'

Basic (in dollars per share)

$0.30

[6]

$0.20

[6]

$0.19

[6]

$0.18

[6]

$0.19

[6]

$0.03

[1],[6]

$0.11

[6]

$0.03

[6]

$0.88

$0.36

$0.80

Diluted (in dollars per share)

$0.30

[6]

$0.19

[6]

$0.19

[6]

$0.18

[6]

$0.19

[6]

$0.03

[1],[6]

$0.11

[6]

$0.03

[6]

$0.86

$0.35

$0.79

Out of period adjustment

'

'

'

'

'

8.2

'

'

'

'

'

Out of period adjustment, prototype development costs

'

'

'

'

'

18.6

'

'

'

'

'

Out of period adjustment, reversal of revenue obligations

'

'

'

'

'

6.2

'

'

'

'

'

Out of period adjustments, inventory purchase

'

'

'

'

'

4.2

'

'

'

'

'

Restructuring Plan 2013 [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Restructuring and other charges

17.6

'

'

'

'

'

'

'

'

'

'

Restructuring Plan 2012 [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Restructuring and other charges

'

'

'

'

'

29.5

'

'

'

'

'

Net income per share attributable to Juniper Networks common stockholders:

'

'

'

'

'

'

'

'

'

'

'

Restructuring related asset impairment charges

'

'

'

'

'

52.4

'

'

'

'

'

Operating expenses [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Amortization of purchased intangibles

'

'

'

'

'

'

'

'

4.6

4.7

5.4

Operating expenses [Member] | Restructuring Plan 2013 [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Restructuring and other charges

'

7.4

'

'

'

'

'

'

'

'

'

Cost of Sales [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Amortization of purchased intangibles

'

'

'

'

'

'

'

'

27.3

27.6

21.7

Cost of Sales [Member] | Restructuring Plan 2013 [Member]

'

'

'

'

'

'

'

'

'

'

'

Operating expenses:

'

'

'

'

'

'

'

'

'

'

'

Restructuring and other charges

'

3.7

'

'

'

'

'

'

'

'

'

Depreciable Assets [Member]

'

'

'

'

'

'

'

'

'

'

'

Net income per share attributable to Juniper Networks common stockholders:

'

'

'

'

'

'

'

'

'

'

'

Change in accounting estimate- depreciation expense impact

($7.90)

($9.40)

($11)

'

'

'

'

'

$28.30

'

'

Change in accounting estimate, diluted net income per share impact

$0.01

$0.01

$0.01

'

'

'

'

'

$0.04

'

'

[1]

During the third quarter of 2012, the Company recorded net out of period adjustments reducing income before income taxes and noncontrolling interest by $8.2 million. These net adjustments resulted in increased research and development expense by $18.6 million related to prototype development costs, partially offset by increased net revenues of $6.2 million related to the reversal of certain revenue obligations and reduced cost of revenues by $4.2 million related to inventory purchases. The Company assessed the materiality of these adjustments, using relevant quantitative and qualitative factors, and determined that these adjustments, both individually and in the aggregate, were not material to any previously reported period.

[2]

In the third quarter of 2013, the Company implemented the 2013 Restructuring Plan for workforce reductions, contract terminations, and project cancellations and recorded restructuring charges of $7.4 million and $3.7 million to operating expenses and cost of revenues, respectively. In the fourth quarter of 2013, the Company continued to implement restructuring activities under the 2013 Restructuring Plan and primarily recorded charges to operating expenses of $17.6 million.

[3]

In the third quarter of 2012, the Company implemented the 2012 Restructuring Plan for workforce reductions, facility consolidations or closures, and supply chain and procurement efficiencies and recorded restructuring charges of $29.5 million. In connection with its restructuring activities, the Company also recorded certain inventory and intangible asset impairment charges totaling $52.4 million to cost of revenues. In the fourth quarter of 2012, the Company continued to implement restructuring activities under the 2012 Restructuring Plan.

[4]

In the second quarter of 2013, the Company extended the useful lives of certainB computers and equipmentB based on actual historical usage,B 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. This change in accounting estimate decreased depreciation expense within research and development expense by approximately $11.0 million or $0.01 per diluted share for the second quarter of 2013, $9.4 million or $0.01 for the third quarter of 2013, and $7.9 million or $0.01 for the fourth quarter of 2013.

[5]

Certain amounts in the prior quarters' Condensed Consolidated Statements of Operations have been reclassified to conform to the current year presentation.

[6]

Net income per share is computed independently. Therefore, the sum of the quarterly net income per share may not equal the total computed for the year or any cumulative interim period.

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	1 Months Ended					2 Months Ended
	Jul. 31, 2013	Feb. 28, 2014	Feb. 28, 2014	Feb. 28, 2014	Feb. 28, 2014	Feb. 25, 2014
		Subsequent Event [Member]	First Quarter of 2015 [Member]	First Quarter of 2014 [Member]	Third Quarter of 2014 [Member]	WANDL, Inc, [Member]
			Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
Subsequent Event [Line Items]	'	'	'	'	'	'
Expected return to shareholders, amount	'	$3,000,000,000	'	'	'	'
Expected return to shareholders, period	'	'3 years	'	'	'	'
Stock repurchase program, authorized amount	1,000,000,000	'	2,000,000,000	1,200,000,000	'	'
Cash dividends per share	'	'	'	'	$0.10	'
Business combination, consideration transferred	'	'	'	'	'	$30,000,000

Schedule_II_Valuation_and_Qual1

Schedule II- Valuation and Qualifying Account (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts [Member]	'	'	'
Movement in Valuation Allowances and Reserves [Roll Forward]	'	'	'
Balance at the beginning of year	$9.50	$9.50	$10.10
Charged to (Reversed from) Costs and Expenses	-3.8	0.1	-0.2
Write-offs, Net of Recoveries	-0.3	-0.1	-0.4
Balance at the end of year	5.4	9.5	9.5
Sales Returns Reserve [Member]	'	'	'
Movement in Valuation Allowances and Reserves [Roll Forward]	'	'	'
Balance at the beginning of year	52.7	52	52.8
Charged as a Reduction in Revenues	35	40	44.9
Charged to Other Accounts	61.5	48.6	64.6
Used	-100.2	-87.9	-110.3
Balance at the end of year	$49	$52.70	$52