2. Investments (Details Narrative)	12 Months Ended
	Dec. 31, 2017
Corporate Bond Securities [Member]
Schedule of Investments [Line Items]
Securities maturity length	41 months 15 days
Certificates of deposit [Member] | Minimum [Member]
Schedule of Investments [Line Items]
Securities maturity length	1 month
Certificates of deposit [Member] | Maximum [Member]
Schedule of Investments [Line Items]
Securities maturity length	11 months 6 days