Line of Business Information - Narrative (Details) - 12 months ended Dec. 31, 2020	line_of_business	segment	Total
Segment Reporting Information [Line Items]
Number of lines of business	2	2
Minimum | Investment Servicing and Management Services | Investment Servicing and Investment Management
Segment Reporting Information [Line Items]
Percentage of consolidated revenues by segment			70.00%
Minimum | Processing and Other Services | Investment Servicing and Investment Management
Segment Reporting Information [Line Items]
Percentage of consolidated revenues by segment			20.00%
Maximum | Investment Servicing and Management Services | Investment Servicing and Investment Management
Segment Reporting Information [Line Items]
Percentage of consolidated revenues by segment			80.00%
Maximum | Processing and Other Services | Investment Servicing and Investment Management
Segment Reporting Information [Line Items]
Percentage of consolidated revenues by segment			30.00%