Segment Information and Concentration of Business Risk, Revenue from Significant Partners (Details) - Partner	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue [Member] | Customer Concentration [Member] | Partner A [Member]
Significant Partners [Abstract]
Concentration percentage	47.00%	4.00%
Revenue [Member] | Customer Concentration [Member] | Partner B [Member]
Significant Partners [Abstract]
Concentration percentage	36.00%	25.00%
Revenue [Member] | Customer Concentration [Member] | Partner C [Member]
Significant Partners [Abstract]
Concentration percentage	12.00%	5.00%
Revenue [Member] | Customer Concentration [Member] | Partner D [Member]
Significant Partners [Abstract]
Concentration percentage	0.00%	56.00%
Contracts Receivables [Member] | Credit Concentration [Member] | Significant Partners [Member]
Significant Partners [Abstract]
Concentration percentage	87.00%		84.00%
Number of significant partners	1		2