Revenue Recognition - Performance Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 11,076	$ 11,082	$ 12,478	$ 12,486
Government Segment
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 140,066	$ 150,500
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | Government Segment
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 56,238
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 | Government Segment
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 47,328
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01 | Government Segment
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 24,434
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01 | Government Segment
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance obligations	$ 12,066