Balance Sheet Offsetting - Summary of Gross Presentation, Instruments Offset (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Financial assets:
Gross Amount Recognized	$ 36.1	$ 18.4
Gross Amount Offset	0.0	0.0
Net Amount Presented	36.1	18.4
Gross Amounts Not Offset, Financial Instruments	0.0	(1.9)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	36.1	16.5
Financial liabilities:
Gross Amount Recognized	197.3	81.6
Gross Amount Offset	0.0	0.0
Net Amount Presented	197.3	81.6
Gross Amounts Not Offset, Financial Instruments	0.0	(1.9)
Gross Amounts Not Offset, Collateral	(188.1)	(77.9)
Net Amount	9.2	1.8
Foreign exchange contracts
Financial assets:
Gross Amount Recognized	8.6	1.2
Gross Amount Offset	0.0	0.0
Net Amount Presented	8.6	1.2
Gross Amounts Not Offset, Financial Instruments	0.0	0.0
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	8.6	1.2
Financial liabilities:
Gross Amount Recognized	9.2	1.8
Gross Amount Offset	0.0	0.0
Net Amount Presented	9.2	1.8
Gross Amounts Not Offset, Financial Instruments	0.0	0.0
Gross Amounts Not Offset, Collateral		0.0
Net Amount	9.2	1.8
Counterparty A \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	0.0	0.2
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	0.2
Gross Amounts Not Offset, Financial Instruments	0.0	(0.2)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	0.0	0.0
Financial liabilities:
Gross Amount Recognized	6.4	2.3
Gross Amount Offset	0.0	0.0
Net Amount Presented	6.4	2.3
Gross Amounts Not Offset, Financial Instruments	0.0	(0.2)
Gross Amounts Not Offset, Collateral	(6.4)	(2.1)
Net Amount	0.0	0.0
Counterparty B \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	0.0	0.1
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	0.1
Gross Amounts Not Offset, Financial Instruments	0.0	(0.1)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	0.0	0.0
Financial liabilities:
Gross Amount Recognized	9.9	5.5
Gross Amount Offset	0.0	0.0
Net Amount Presented	9.9	5.5
Gross Amounts Not Offset, Financial Instruments	0.0	(0.1)
Gross Amounts Not Offset, Collateral	(9.9)	(5.4)
Net Amount	0.0	0.0
Counterparty C \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	0.0	0.4
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	0.4
Gross Amounts Not Offset, Financial Instruments	0.0	(0.4)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	0.0	0.0
Financial liabilities:
Gross Amount Recognized	64.2	28.2
Gross Amount Offset	0.0	0.0
Net Amount Presented	64.2	28.2
Gross Amounts Not Offset, Financial Instruments	0.0	(0.4)
Gross Amounts Not Offset, Collateral	(64.2)	(27.8)
Net Amount	0.0	0.0
Counterparty D \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	0.0	0.1
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	0.1
Gross Amounts Not Offset, Financial Instruments	0.0	(0.1)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	0.0	0.0
Financial liabilities:
Gross Amount Recognized	24.6	10.9
Gross Amount Offset	0.0	0.0
Net Amount Presented	24.6	10.9
Gross Amounts Not Offset, Financial Instruments	0.0	(0.1)
Gross Amounts Not Offset, Collateral	(24.6)	(10.8)
Net Amount	0.0	0.0
Counterparty E \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	27.5	15.3
Gross Amount Offset	0.0	0.0
Net Amount Presented	27.5	15.3
Gross Amounts Not Offset, Financial Instruments	0.0	0.0
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	27.5	15.3
Financial liabilities:
Gross Amount Recognized	0.0	0.0
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	0.0
Gross Amounts Not Offset, Financial Instruments	0.0	0.0
Gross Amounts Not Offset, Collateral		0.0
Net Amount	0.0	0.0
Other Counterparties \| Interest Rate Swaps/Caps
Financial assets:
Gross Amount Recognized	0.0	1.1
Gross Amount Offset	0.0	0.0
Net Amount Presented	0.0	1.1
Gross Amounts Not Offset, Financial Instruments	0.0	(1.1)
Gross Amounts Not Offset, Collateral	0.0	0.0
Net Amount	0.0	0.0
Financial liabilities:
Gross Amount Recognized	83.0	32.9
Gross Amount Offset	0.0	0.0
Net Amount Presented	83.0	32.9
Gross Amounts Not Offset, Financial Instruments	0.0	(1.1)
Gross Amounts Not Offset, Collateral	(83.0)	(31.8)
Net Amount	$ 0.0	$ 0.0

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