Cash, Cash Equivalents, And Marketable Securities Cash, Cash Equivalents, And Marketable Securities narrative (Details) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Cash, Cash Equivalents And Marketable Securities [Abstract]
Available-for-sale Securities, Gross Unrealized Gains	$ 3,341,000
Available-for-sale Equity Securities, Amortized Cost Basis	0
Available-for-sale Securities, Equity Securities	$ 3,341,000	$ 0

Amount of equity securities categorized neither as held-to-maturity nor as trading.

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-Name Emerging Issues Task Force (EITF)

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-Publisher FASB

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Reference 10: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Before tax and reclassification adjustments amount of unrealized holding gain (loss) and transfers on available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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+ Details