Business Segments, Concentration of Credit Risk and Significant Customers (Details 2)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total revenues | Customer concentration risk | Customer A
Significant Customers
Percentage of concentration risk	41.00%	28.00%	23.00%
Total revenues | Customer concentration risk | Customer B
Significant Customers
Percentage of concentration risk	13.00%	26.00%	12.00%
Total revenues | Customer concentration risk | Customer C
Significant Customers
Percentage of concentration risk		12.00%	17.00%
Net accounts receivable | Credit concentration | Three customers
Significant Customers
Percentage of concentration risk		100.00%
Number of customers		3
Net accounts receivable | Credit concentration | Two customers
Significant Customers
Percentage of concentration risk	96.00%
Number of customers	2