Fair Value Measurement (Narrative)(Details) (USD $)	9 Months Ended	12 Months Ended
Sep. 30, 2012	Dec. 31, 2011	Oct. 22, 2012	Jan. 17, 2012 Company A [Member]	Jan. 17, 2012 Residential Construction Industry [Member]	Jan. 17, 2012 Cement Business [Member] Company B [Member]	Sep. 30, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Equity Securities	$ 20,100,000	$ 17,400,000					$ 2,600,000	$ 2,600,000
Other-than-temporary impairment	$ 0	$ (415,287)
Recovery of temporary impairment			36.00%	60.00%	34.00%	93.00%

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

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

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

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+ Details

- Definition

The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References+ Details