Revenues - Changes in Balances of Deferred Costs to Obtain and Fulfill Contracts (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Deferred Costs to Obtain Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance at beginning of period	$ 779
Costs deferred	70
Amortization	(359)
Balance at end of period	490
Deferred Costs to Fulfill Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance at beginning of period	281
Costs deferred	81
Amortization	(134)
Balance at end of period	$ 228