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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
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Mar. 31, 2022 | Mar. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | $ 60.5 | $ 74.1
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.9) | (1.7)
Amount of Gain (Loss) Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | 0.5 | 0.6
Interest expense [Member] | Interest Rate Contracts [Member] |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | 67.0 | 75.8
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.3) | (0.3)
Commission revenue [Member] | Foreign Exchange Contracts [Member] |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of Gain (Loss) Recognized in Accumulated Other Comprehensive Loss | [1] | (6.5) | (1.7)
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.3) | (0.9)
Amount of Gain (Loss) Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  |  | (0.1)
Compensation expense [Member] |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.2) | (0.3)
Amount of Gain (Loss) Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | 0.3 | 0.4
Operating expense [Member] |  |  |
Derivative Instruments, Gain (Loss) [Line Items] |  |  |
Amount of Loss Reclassified from Accumulated Other Comprehensive Loss into Earnings |  | (0.1) | (0.2)
Amount of Gain (Loss) Recognized in Earnings Related to Amount Excluded from Effectiveness Testing |  | $ 0.2 | $ 0.3
[1] | For the three-month periods ended March 31, 2022 and 2021, the amount excluded from the assessment of hedge effectiveness for our foreign exchange contracts recognized in accumulated other comprehensive loss was a loss of $0.7 million and $1.2 million, respectively.

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