Acquisition - Additional Information (Details) $ / shares in Units, $ in Thousands, $ in Millions					3 Months Ended	12 Months Ended
	Dec. 13, 2021 USD ($)	Dec. 07, 2021 USD ($)	Jun. 17, 2021 USD ($) Unit $ / shares	Jun. 17, 2021 AUD ($) Unit	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill					$ 837,910	$ 838,867
Redflex Holdings Limited
Business Acquisition [Line Items]
Date of acquisition					Jun. 17, 2021
Number of reporting units | Unit			2	2
Goodwill			$ 56,214
Redflex Holdings Limited | Trademarks
Business Acquisition [Line Items]
Identifiable intangible assets useful life			5 years	5 years
Intangible assets			$ 900
Redflex Holdings Limited | Customer Relationships
Business Acquisition [Line Items]
Identifiable intangible assets useful life			10 years	10 years
Intangible assets			$ 25,900
Redflex Holdings Limited | Developed Technology
Business Acquisition [Line Items]
Identifiable intangible assets useful life			8 years 8 months 12 days	8 years 8 months 12 days
Intangible assets			$ 18,200
Redflex Holdings Limited | Scheme Amendment
Business Acquisition [Line Items]
Purchase percentage of outstanding equity			100.00%
Consideration payable per share | $ / shares			$ 0.96
Consideration amount			$ 117,900	$ 152.5
Transaction costs related to acquisition			$ 9,700
T2 Systems Acquisition
Business Acquisition [Line Items]
Date of acquisition		Dec. 07, 2021
Goodwill		$ 195,226
T2 Systems Acquisition | Trademarks
Business Acquisition [Line Items]
Identifiable intangible assets useful life		10 years
Intangible assets		$ 3,200
T2 Systems Acquisition | Customer Relationships
Business Acquisition [Line Items]
Identifiable intangible assets useful life		10 years
Intangible assets		$ 164,300
T2 Systems Acquisition | Developed Technology
Business Acquisition [Line Items]
Identifiable intangible assets useful life		6 years 1 month 6 days
Intangible assets		$ 19,300
T2 Systems Acquisition | T2 Merger Agreement
Business Acquisition [Line Items]
Transaction costs related to acquisition		2,900
Purchase price		$ 353,200
NuPark
Business Acquisition [Line Items]
Date of acquisition	Dec. 13, 2021					Dec. 13, 2021
Identifiable intangible assets useful life	10 years
Intangible assets						$ 300
Purchase price	$ 7,000
Goodwill	$ 3,200
NuPark | Customer Relationships
Business Acquisition [Line Items]
Intangible assets						$ 4,900