Revenue Recognition - Performance Obligations (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 18,091	$ 11,082	$ 12,027	$ 12,486
Government
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 141,207	$ 150,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Restaurant/Retail
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	60 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01 | Government
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	1 year
Performance obligations	$ 67,995
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Restaurant/Retail
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation, percentage	100.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Restaurant/Retail | Current
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligation, percentage	71.00%
Performance obligations, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01 | Government
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	1 year
Performance obligations	$ 39,101
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-07-01 | Government
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	1 year
Performance obligations	$ 22,647
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-07-01 | Government
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period
Performance obligations	$ 11,464