Significant Accounting Policies - Estimated Useful Lives for Significant Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Purchased software, including capitalized software development costs
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Computer hardware
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Furniture and office equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum | Furniture and office equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years