Revenue Recognition - Schedule of Performance Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 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	$ 14,258
Contract with Customer, Liability, Revenue Recognized			(4,677)	828
Contract With Customer, Liability, Changes In Customer Deposits			1,390	(115)
Ending balance	$ 12,713	$ 14,971	12,713	14,971
Performance obligations	12,713	14,971	12,713	14,971	$ 12,713	$ 16,000
Restaurant/Retail
Revenue, Remaining Performance Obligation [Roll Forward]
Beginning balance			10,900
Contract with Customer, Liability, Revenue Recognized	(2,200)	$ (2,100)	(9,900)	$ (8,600)
Ending balance	9,900		9,900
Performance obligations	9,900		10,900		9,900	10,900
Government
Revenue, Remaining Performance Obligation [Roll Forward]
Beginning balance			148,700
Ending balance	162,455		162,455
Performance obligations	$ 162,455		$ 162,455		162,455	148,700
Funded performance obligations					$ 36,000	$ 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