Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2020 reporting_unit
Property, Plant and Equipment [Line Items]
Fair value of recognized acquired assets (percent)	100.00%
Non controlling interest in acquisitions (percent)	100.00%
Recognized liabilities acquired (percent)	100.00%
Number of reporting units	1
Estimated forfeitures (percent)	3.00%
Percentage of excess in projected benefit obligation and fair value assets to be amortized (percent)	10.00%
Buildings
Property, Plant and Equipment [Line Items]
Useful life of property and equipment	50 years
Minimum
Property, Plant and Equipment [Line Items]
Useful life of property and equipment	3 years
Intangible assets, useful life, years	2 years
Reporting period lag between Parent Company and Consolidated Entity	1 month
Minimum | Software development
Property, Plant and Equipment [Line Items]
Useful life of property and equipment	5 years
Maximum
Property, Plant and Equipment [Line Items]
Sales commissions amortization period	6 years
Useful life of property and equipment	7 years
Intangible assets, useful life, years	12 years
Settlement period for Fund and Investor Receivables	4 days
Reporting period lag between Parent Company and Consolidated Entity	3 months
Maximum | Software development
Property, Plant and Equipment [Line Items]
Useful life of property and equipment	7 years