XML 84 R41.htm IDEA: XBRL DOCUMENT v2.4.1.9
Cash Equivalents, and Investments, Narrative (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Investment
Mar. 31, 2014
Dec. 31, 2014
Investment
Cash Equivalents and Investments [Abstract]      
Total investments in unrealized loss position 354us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1   437us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Available-for-sale securities, other than temporary impairment $ 0us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities $ 1.6us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNetAvailableforsaleSecurities  
Available-for-sale securities, gross realized gains 165.5us-gaap_AvailableForSaleSecuritiesGrossRealizedGains    
Privately-held investments 93.1jnpr_PrivatelyheldInvestments   89.9jnpr_PrivatelyheldInvestments
Privately held investments at fair value 50.3jnpr_Privatelyheldinvestmentsatfairvalue   47.5jnpr_Privatelyheldinvestmentsatfairvalue
Unrealized gain (loss) on privately-held debt securities $ 0us-gaap_UnrealizedGainLossOnMarketableSecuritiesCostMethodInvestmentsAndOtherInvestments $ 0us-gaap_UnrealizedGainLossOnMarketableSecuritiesCostMethodInvestmentsAndOtherInvestments