Concentration of Business Risk (Details)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2013 Revenue Partner A	Sep. 30, 2012 Revenue Partner A	Sep. 30, 2013 Revenue Partner A	Sep. 30, 2012 Revenue Partner A	Sep. 30, 2013 Revenue Partner B	Sep. 30, 2012 Revenue Partner B	Sep. 30, 2013 Revenue Partner B	Sep. 30, 2012 Revenue Partner B	Sep. 30, 2013 Revenue Partner C	Sep. 30, 2012 Revenue Partner C	Sep. 30, 2013 Revenue Partner C	Sep. 30, 2012 Revenue Partner C	Sep. 30, 2013 Revenue Partner D	Sep. 30, 2012 Revenue Partner D	Sep. 30, 2013 Revenue Partner D	Sep. 30, 2012 Revenue Partner D	Sep. 30, 2013 Contract receivables Significant Partners entity	Dec. 31, 2012 Contract receivables Significant Partners entity
Concentration of business risk
Concentration percentage	48.00%	18.00%	22.00%	7.00%	18.00%	0.00%	21.00%	0.00%	25.00%	21.00%	16.00%	7.00%	0.00%	41.00%	31.00%	78.00%	93.00%	83.00%
Number of significant partners																	2	4