Revenues - Changes in Balances of Deferred Costs to Obtain and Fulfill Contracts (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Deferred Costs to Obtain Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance at beginning of period	$ 779
Costs deferred	104
Amortization	(510)
Balance at end of period	373
Deferred Costs to Fulfill Contracts [Member]
Capitalized Contract Cost [Line Items]
Balance at beginning of period	281
Costs deferred	129
Amortization	(190)
Balance at end of period	$ 220