Commitments and contingencies (Details 2) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) item
Employment contracts
Number of officers with whom the entity entered into employment contracts | item	9
Underpaid revenue share payments and related interest
Other matters
Claim value | $	$ 4,600
Letter of Credit
Letters of credit
Current issued borrowing capacity | $	$ 3,643
Term period of Letters of Credit agreements	11 months
Number of drafts drawn under Letters of Credit | item	0