Commitments and Contingent Liabilities - Summary of Off-Balance Sheet Financial Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
ONE YEAR AND LESS	$ 169,299.6	$ 183,566.4
OVER ONE YEAR	18,310.9	18,410.2
TOTAL	187,610.5	201,976.6
Undrawn Commitments
Loss Contingencies [Line Items]
Commitments, participated to others	299.3	366.6
Custody Securities Lent with Indemnification
Loss Contingencies [Line Items]
ONE YEAR AND LESS	149,303.1	170,445.3
OVER ONE YEAR	0.0	0.0
TOTAL	149,303.1	170,445.3
Secured by Cash Deposits or Participated to Others | Standby Letters of Credit
Loss Contingencies [Line Items]
TOTAL	37.2	30.5
Standby Letter of Credit and Financial Guarantee
Loss Contingencies [Line Items]
Guarantor obligations, current carrying value	7,178.8	2,309.6
Undrawn Commitments
Loss Contingencies [Line Items]
ONE YEAR AND LESS	12,146.2	9,567.0
OVER ONE YEAR	17,233.4	17,855.2
TOTAL	29,379.6	27,422.2
Standby Letters of Credit
Loss Contingencies [Line Items]
ONE YEAR AND LESS	7,815.4	3,485.6
OVER ONE YEAR	1,076.7	553.9
TOTAL	8,892.1	4,039.5
Commercial Letters of Credit
Loss Contingencies [Line Items]
ONE YEAR AND LESS	34.9	68.5
OVER ONE YEAR	0.8	1.1
TOTAL	$ 35.7	$ 69.6