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Cash Equivalents And Investments (Schedule Of Estimated Fair Value Of Available-For-Sale Securities) (Details) (USD $)
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Mar. 31, 2015
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Dec. 31, 2014
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| Schedule of Available-for-sale Securities [Line Items] | ||
| Fair Value | $ 15,905,000us-gaap_AvailableForSaleSecuritiesDebtSecurities | $ 17,216,000us-gaap_AvailableForSaleSecuritiesDebtSecurities |
| Investments [Member] | ||
| Schedule of Available-for-sale Securities [Line Items] | ||
| Due within one year, Amortized Cost |
4,634,000us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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| Due after one year through five years, Amortized Cost |
10,582,000us-gaap_AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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| Amortized Cost |
15,216,000us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAmortizedCost / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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| Due within one year, Fair Value |
4,878,000us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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| Due after one year through five years, Fair Value |
10,585,000us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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| Fair Value |
$ 15,463,000us-gaap_AvailableForSaleSecuritiesDebtSecurities / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
$ 16,143,000us-gaap_AvailableForSaleSecuritiesDebtSecurities / jcs_AdditionalInvestmentInformationAxis = us-gaap_InvestmentsMember |
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- Definition
Amount of available-for-sale debt securities at fair value maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of available-for-sale debt securities at cost, net of adjustments, which include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the next rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments. No definition available.
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- Definition
Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second rolling twelve months through the fifth rolling twelve months following the latest balance sheet presented. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments. No definition available.
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- Definition
Amount of available-for-sale debt securities at fair value maturing in the next fiscal year following the latest fiscal year. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of debt securities categorized neither as held-to-maturity nor trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Details
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