Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Maturity date of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in CCYY-MM-DD format.

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Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

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Fair value of financial and nonfinancial obligations.

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Amount before tax, after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Financial Instruments Measured At Fair Value, on Recurring Basis (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	$ 99.5		$ 99.5		$ 46.6
Investments, Fair Value Disclosure [Abstract]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	5.1		5.1
Level 2
Investments, Fair Value Disclosure [Abstract]
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	0.0	$ 0.1	0.0	$ 0.1
Available-for-sale Securities, Gross Realized Gain (Loss)	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Level 2 \| Minimum [Member]
Investments, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale, Maturity Date	Jan. 01, 2027		Jan. 01, 2027
Level 2 \| Maximum [Member]
Investments, Fair Value Disclosure [Abstract]
Debt Securities, Available-for-sale, Maturity Date	Dec. 31, 2033		Dec. 31, 2033
Fair Value, Recurring
Assets, Fair Value Disclosure [Abstract]
Total	$ 3.0		$ 3.0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	99.5		99.5
Business Combination, Contingent Consideration, Liability	5.0		5.0
Total	104.5		104.5
Investments, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Current	3.0		3.0
Fair Value, Recurring \| Level 1
Assets, Fair Value Disclosure [Abstract]
Total	0.0		0.0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	0.0		0.0
Business Combination, Contingent Consideration, Liability	0.0		0.0
Total	0.0		0.0
Investments, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Current	0.0		0.0
Fair Value, Recurring \| Level 2
Assets, Fair Value Disclosure [Abstract]
Total	3.0		3.0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	99.5		99.5
Business Combination, Contingent Consideration, Liability	0.0		0.0
Total	99.5		99.5
Investments, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Current	3.0		3.0
Fair Value, Recurring \| Level 3
Assets, Fair Value Disclosure [Abstract]
Total	0.0		0.0
Liabilities, Fair Value Disclosure [Abstract]
Interest rate swaps	0.0		0.0
Business Combination, Contingent Consideration, Liability	5.0		5.0
Total	5.0		5.0
Investments, Fair Value Disclosure [Abstract]
Available-for-sale Securities, Current	$ 0.0		$ 0.0