Summary of Significant Accounting Policies - Estimated Useful Lives by Major Asset Category (Details)	12 Months Ended
	Dec. 31, 2020
Minimum | Contractual and Customer Relationships
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	3 years
Minimum | Non-compete Agreements
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	3 years
Minimum | Developed Technology
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	5 years
Maximum | Contractual and Customer Relationships
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	15 years
Maximum | Non-compete Agreements
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	5 years
Maximum | Developed Technology
Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	7 years
Computer Hardware and Software
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Computer Software, Intangible Asset | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Computer Software, Intangible Asset | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Signage
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Agent Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Agent Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Useful life (in years)	10 years