Related party transactions (Details) (USD $)	Dec. 31, 2012	Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2009	May 21, 2009	Nov. 20, 2007	Jul. 01, 2006
Company made an unsecured loan to ERC in millions							1.4
Annual interest rate of unsecured loan to ERC							8.00%
Balance of the two notes and accrued interest					$ 3,970,897
Company made a loan to PIAMI						630,000
Company made additional net advances on the loan to PIAMI in millions		360,000				6.3
Balance due including accrued interest PIAMI in millions				11.1
Outstanding principal and interest in millions			10.4
Payments from PIAMI		715,000
The Company and several other defendants settled a lawsuit	225,000
Paid the entire amount and has a note receivable from one of the other defendants	$ 112,500