Non-controlling interests (Details Textual) - Jun. 30, 2014 - USD ($) $ in Millions	Total
Noncontrolling Interest [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired	51.00%
Fujian Qiaolong [Member]
Noncontrolling Interest [Line Items]
Noncontrolling Interest Increase Decrease from Business Combination Fair Value	$ 2.8
Business Acquisition, Percentage of Voting Interests Acquired	51.00%