Significant Concentrations and Risks (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 Supplier	Jun. 30, 2012	Dec. 31, 2012
Significant concentrations and risks (Textual)
Cash and pledged bank deposits in financial institutions	$ 299		$ 299		$ 255
Number of major supplier			3
Purchase (net of VAT) from major supplier	67	155	246	275
Purchase from major supplier percentage	64.00%	83.00%	80.00%	80.00%
Purchase from largest supplier, Amount	52	148	187	237
Purchase from largest supplier, Percentage	50.00%	72.00%	61.00%	70.00%
Purchase of heavy oil	140.9
Sale of heavy oil	140.53
Trading loss of heavy oil	$ 0.37