Restructuring - Restructuring Charges By Plan (Details) - DN Now Plan [Member] $ in Millions	Dec. 31, 2021 USD ($)
Severance
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	$ 200.2
Severance | Eurasia Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	89.4
Severance | Americas Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	16.1
Severance | Retail Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	39.9
Severance | Corporate And Reconciling Items [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	54.8
Other Restructuring
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	18.7
Other Restructuring | Eurasia Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	2.6
Other Restructuring | Americas Banking Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	0.1
Other Restructuring | Retail Segment [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	3.8
Other Restructuring | Corporate And Reconciling Items [Member]
Restructuring Cost and Reserve [Line Items]
Costs incurred to date	$ 12.2