Concentration of Risk (Details)	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] item	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] item	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] item	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] item	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] Largest Customer [Member]	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] Largest Customer [Member]	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] Largest Customer [Member]	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] Largest Customer [Member]	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] Second Largest Customer [Member]	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] Second Largest Customer [Member]	Jun. 30, 2014 Sales Revenue Net [Member] Customer Concentration Risk [Member] Second Largest Customer [Member]	Jun. 30, 2013 Sales Revenue Net [Member] Customer Concentration Risk [Member] Third Largest Customer [Member]	Jun. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] item	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] item	Jun. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] Largest Customer [Member]	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] Largest Customer [Member]	Jun. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] Second Largest Customer [Member]	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] Second Largest Customer [Member]	Jun. 30, 2014 Accounts Receivable [Member] Credit Concentration Risk [Member] Third Largest Customer [Member]	Dec. 31, 2013 Accounts Receivable [Member] Credit Concentration Risk [Member] Third Largest Customer [Member]
Concentration of risk
Number of customers	2	3	2	1									3	3
Percentage of concentration risk					15.90%	15.10%	24.50%	10.60%	11.10%	14.70%	12.50%	10.60%			15.00%	23.20%	13.40%	14.20%	12.70%	13.60%