Fair value measurements (Details 1) (USD $)	6 Months Ended
	Jun. 30, 2014
Fair Value Inputs, Equity, Quantitative Information [Line Items]
Balance, Beginning	$ 6,623,448
Profit sharing and equity from earnings of OC-BVI	190,954
Distribution of earnings from OC-BVI	(727,200)
Balance, Ending	$ 6,087,202