Revenue Recognition - Schedule of Performance Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Support contract timing			12
Revenue, Remaining Performance Obligation [Roll Forward]
Beginning balance			$ 16,000	$ 14,134
Change in deferred revenue			(430)	(327)
Changes in customer deposits			(2,008)	1,272
Ending balance	$ 13,562	$ 15,079	13,562	15,079
Performance obligations	13,562	15,079	13,562	15,079	$ 13,562	$ 16,000
Restaurant/Retail
Revenue, Remaining Performance Obligation [Roll Forward]
Beginning balance			10,900
Change in deferred revenue	(3,600)	$ (3,900)	(7,700)	$ (9,000)
Ending balance	10,500		10,500
Performance obligations	10,500		10,900		10,500	10,900
Government
Revenue, Remaining Performance Obligation [Roll Forward]
Beginning balance			148,700
Ending balance	129,613		129,613
Performance obligations	$ 129,613		$ 129,613		129,613	148,700
Funded performance obligations					$ 35,500	$ 32,800
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Payment period			30 days
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Payment period			90 days