Financial Instruments-Available for Sale Securities (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair value of short term investment unrealized holdings and gains
Amortized Cost	$ 30,237		$ 42,979
Aggregate fair value	30,230us-gaap_AvailableForSaleSecurities		42,987us-gaap_AvailableForSaleSecurities
Unrealized Holdings gains	0	8
Unrealized Holdings Losses	$ 7	$ 0

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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-Publisher FASB

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This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.2)

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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