Revenues, Costs to Obtain and Fulfill Contracts (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($)
Costs to obtain and fulfill contracts [Abstract]
Deferred costs expected period of benefit	30 months
Deferred Costs to Obtain Contracts [Member]
Changes in Balances of Deferred Costs to Obtain and Fulfill Contracts [Abstract]
Balance at beginning of period	$ 1,413
Costs deferred	275
Amortization	(571)
Balance at end of period	1,117
Deferred Costs to Fulfill Contracts [Member]
Changes in Balances of Deferred Costs to Obtain and Fulfill Contracts [Abstract]
Balance at beginning of period	606
Costs deferred	101
Amortization	(310)
Balance at end of period	$ 397