Commitments, Contingencies and Off-Balance Sheet Arrangements - Contractual Obligations (Detail) $ in Millions	Sep. 30, 2022 USD ($)
Senior Notes [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, Thereafter	$ 1,600.0
Contractual Obligations, Payments Due by Period, Total	1,600.0
Note Purchase Agreements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2023	250.0
Contractual Obligations, Payments Due by Period, 2024	475.0
Contractual Obligations, Payments Due by Period, 2025	200.0
Contractual Obligations, Payments Due by Period, 2026	640.0
Contractual Obligations, Payments Due by Period, Thereafter	2,683.0
Contractual Obligations, Payments Due by Period, Total	4,248.0
Credit Agreement [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	190.0
Contractual Obligations, Payments Due by Period, Total	190.0
Premium Financing Debt Facility [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	245.4
Contractual Obligations, Payments Due by Period, Total	245.4
Interest On Debt [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	61.6
Contractual Obligations, Payments Due by Period, 2023	229.0
Contractual Obligations, Payments Due by Period, 2024	212.3
Contractual Obligations, Payments Due by Period, 2025	197.7
Contractual Obligations, Payments Due by Period, 2026	178.8
Contractual Obligations, Payments Due by Period, Thereafter	1,568.5
Contractual Obligations, Payments Due by Period, Total	2,447.9
Total Debt Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	497.0
Contractual Obligations, Payments Due by Period, 2023	479.0
Contractual Obligations, Payments Due by Period, 2024	687.3
Contractual Obligations, Payments Due by Period, 2025	397.7
Contractual Obligations, Payments Due by Period, 2026	818.8
Contractual Obligations, Payments Due by Period, Thereafter	5,851.5
Contractual Obligations, Payments Due by Period, Total	8,731.3
Operating Lease Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	17.0
Contractual Obligations, Payments Due by Period, 2023	103.5
Contractual Obligations, Payments Due by Period, 2024	78.0
Contractual Obligations, Payments Due by Period, 2025	63.7
Contractual Obligations, Payments Due by Period, 2026	51.4
Contractual Obligations, Payments Due by Period, Thereafter	109.0
Contractual Obligations, Payments Due by Period, Total	422.6
Less Sublease Arrangements [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Receivable by Period, 2022	(0.2)
Contractual Obligations, Payments Receivable by Period, 2023	(0.5)
Contractual Obligations, Payments Receivable by Period, 2024	(0.3)
Contractual Obligations, Payments Receivable by Period, 2025	(0.2)
Contractual Obligations, Payments Receivable by Period, 2026	(0.2)
Contractual Obligations, Payments Receivable by Period, Thereafter	(0.2)
Contractual Obligations, Payments Receivable by Period, Total	(1.6)
Outstanding Purchase Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	29.5
Contractual Obligations, Payments Due by Period, 2023	95.7
Contractual Obligations, Payments Due by Period, 2024	82.6
Contractual Obligations, Payments Due by Period, 2025	33.7
Contractual Obligations, Payments Due by Period, 2026	16.1
Contractual Obligations, Payments Due by Period, Thereafter	26.2
Contractual Obligations, Payments Due by Period, Total	283.8
Total Contractual Obligations [Member]
Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]
Contractual Obligations, Payments Due by Period, 2022	543.3
Contractual Obligations, Payments Due by Period, 2023	677.7
Contractual Obligations, Payments Due by Period, 2024	847.6
Contractual Obligations, Payments Due by Period, 2025	494.9
Contractual Obligations, Payments Due by Period, 2026	886.1
Contractual Obligations, Payments Due by Period, Thereafter	5,986.5
Contractual Obligations, Payments Due by Period, Total	$ 9,436.1

Commitments Contingencies And Off Balance Sheet Arrangements [Line Items]

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Recorded unconditional purchase obligation due after fourth year.

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Recorded unconditional purchase obligation receivable.

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Recorded unconditional purchase obligation receivable after forth year.

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Recorded unconditional purchase obligation receivable in fourth year.

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Recorded unconditional purchase obligation receivable in remainder of fiscal year.

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- Definition

Recorded unconditional purchase obligation receivable in second year.

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Recorded unconditional purchase obligation receivable in third year.

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- Definition

Recorded unconditional purchase obligation receivable within one year.

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- Definition

Amount of the recorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 6
-URI https://asc.fasb.org/extlink&oid=123406679&loc=d3e25383-109308

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- Definition

Amount of recorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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- Definition

Amount of recorded unconditional purchase obligation to be paid in remainder of current fiscal year.

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Amount of recorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of recorded unconditional purchase obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of recorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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