Fair Value Measurements (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value Disclosures [Abstract]
Unrealized gains/ (losses) from marketable securities	$ (82)	$ (486)	$ (1,083)
Proceeds from available for sale municipal bonds	16,838	12,507	11,877
Realized gain on other income, investment and interest	$ 229	$ 95	$ 69

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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- Definition

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) and the change in net unrealized holding gain (loss) is included in earnings for the period.

+ References

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

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-Subparagraph (SX 210.5-03.7(c))

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