Concentration of Risk (Details)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014 Consolidated revenue Customer concentration risk item	Sep. 30, 2013 Consolidated revenue Customer concentration risk item	Sep. 30, 2014 Consolidated revenue Customer concentration risk item	Sep. 30, 2013 Consolidated revenue Customer concentration risk item	Sep. 30, 2014 Consolidated revenue Customer concentration risk One customer	Sep. 30, 2013 Consolidated revenue Customer concentration risk One customer	Sep. 30, 2014 Consolidated revenue Customer concentration risk One customer	Sep. 30, 2013 Consolidated revenue Customer concentration risk One customer	Sep. 30, 2014 Consolidated revenue Customer concentration risk Second customer	Sep. 30, 2013 Consolidated revenue Customer concentration risk Second customer	Sep. 30, 2014 Consolidated revenue Customer concentration risk Second customer	Sep. 30, 2013 Consolidated revenue Customer concentration risk Second customer	Sep. 30, 2014 Consolidated gross accounts receivable Credit concentration risk item	Dec. 31, 2013 Consolidated gross accounts receivable Credit concentration risk item	Sep. 30, 2014 Consolidated gross accounts receivable Credit concentration risk One customer	Dec. 31, 2013 Consolidated gross accounts receivable Credit concentration risk One customer	Sep. 30, 2014 Consolidated gross accounts receivable Credit concentration risk Second customer	Dec. 31, 2013 Consolidated gross accounts receivable Credit concentration risk Second customer	Dec. 31, 2013 Consolidated gross accounts receivable Credit concentration risk Third customer
Concentration of risk
Number of customers	2	2	2	2									2	3
Percentage of concentration risk					11.00%	19.00%	18.80%	10.90%	10.50%	14.50%	10.80%	10.40%			27.10%	23.20%	14.80%	14.20%	13.60%