Revenues - Disaggregation of Revenues (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenues		$ 7,275	$ 12,476	$ 15,935	$ 25,924
Subscriptions [Member]
Disaggregation Of Revenue [Line Items]
Revenues		4,938	9,427	11,271	19,853
Strategic Agreements [Member]
Disaggregation Of Revenue [Line Items]
Revenues		2,337	3,049	4,664	6,071
United States of America [Member]
Disaggregation Of Revenue [Line Items]
Revenues		5,527	9,292	12,082	19,333
United Kingdom [Member]
Disaggregation Of Revenue [Line Items]
Revenues		904	1,483	1,904	3,028
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	[1]	$ 844	$ 1,701	$ 1,949	$ 3,563

[1] No individual country within the “Other” category accounted for 10% or more of revenues, net for any period presented.