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Derivatives and Hedging Activity - Summary of Amounts of Derivative Gains (Losses) Recognized In Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
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Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | $ 44.9 | $ (26.3) | $ 82.4 | $ 71.0
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.9) | 2.0 | (2.4) | 0.8
Amount of Gain Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | 0.6 | 0.9 | 2.3 | 2.3
Interest Rate Contracts [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | $ (0.3) | $ (0.2) | $ (0.9) | $ (0.8)
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration] |  | Interest Expense | Interest Expense | Interest Expense | Interest Expense
Foreign Exchange Contracts [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | $ 0.1 | $ 2.9 | $ 0.9 | $ (2.7)
Amount of Gain Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | $ (0.1) |  | $ (0.1) |
Derivative Instrument, Gain (Loss) Reclassified from AOCI into Income, Effective Portion, Statement of Income or Comprehensive Income [Extensible Enumeration] |  | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax | Revenue from Contract with Customer, Excluding Assessed Tax
Interest expense [Member] | Interest Rate Contracts [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | $ 56.2 | $ 45.5 | $ 65.0 | $ 181.0
Commission revenue [Member] | Foreign Exchange Contracts [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | (11.3) | (71.8) | 17.4 | (110.0)
Compensation expense [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.4) | (0.4) | (1.4) | (0.6)
Amount of Gain Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | 0.4 | 0.5 | 1.4 | 1.3
Operating expense [Member] |  |  |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |  |  |
Amount of Gain (Loss) Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.3) | (0.3) | (1.0) | (0.5)
Amount of Gain Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | $ 0.3 | $ 0.4 | $ 1.0 | $ 1.0
[1] | For the three and nine-month periods ended September 30, 2023, the amount excluded from the assessment of hedge effectiveness for our foreign exchange contracts recognized in accumulated other comprehensive loss was a loss of $0.1 million and a gain of $0.7 million, respectively. For the three and nine-month periods ended September 30, 2022, the amount excluded from the assessment of hedge effectiveness for our foreign exchange contracts recognized in accumulated other comprehensive loss was a gain of $0.8 million and $1.3 million, respectively.

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