Fair Value Measurements (Details Narrative) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($) integer	Dec. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)
Number of corporate bonds | integer	59
Unrealized gain on corporate bonds	$ 1,584
Realized gain on corporate bonds	242
Amortized cost of investments	128,474
Carrying amount of corporate bonds	130,058	$ 137,867
Carrying amount of other long-term debt	88,993		$ 88,857
Fair value of other long-term debt	95,606		$ 92,541
Fair Value, Measurements, Recurring [Member]
Assets measured at fair value	$ 130,058