Goodwill (Details Textual) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Impairment of goodwill	$ 0	$ 0	$ 2,541,476
Income Tax Reconciliation, Nondeductible Expense, Impairment Losses			$ 2,541,476

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

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+ Details