Short-Term Debt - Additional Information (Detail) - USD ($)				9 Months Ended	12 Months Ended
	Oct. 30, 2020	Jul. 14, 2020	Feb. 06, 2020	Sep. 30, 2020	Dec. 31, 2019
Line Of Credit Facility [Line Items]
Weighted-average interest rate				0.82%	2.56%
Line of credit facility maximum borrowing capacity				$ 850,000,000	$ 550,000,000
3-year Accounts Receivable Facility [Member]
Line Of Credit Facility [Line Items]
Credit facility amendment date		Jul. 14, 2020
Line of credit facility maximum borrowing capacity		$ 150,000,000		$ 150,000,000	$ 150,000,000
Credit facility maturity date				Mar. 22, 2021	Mar. 22, 2021
3-year Accounts Receivable Facility [Member] | Subsequent Event [Member]
Line Of Credit Facility [Line Items]
Credit facility amendment date	Oct. 30, 2020
Line of credit facility maximum borrowing capacity	$ 150,000,000
364-day Credit Agreement [Member]
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity			$ 300,000,000
Credit facility maturity period			364 days
Credit facility maturity date			Feb. 04, 2021
Minimum [Member]
Line Of Credit Facility [Line Items]
Commitment fees, percentage				0.125%
Maximum [Member]
Line Of Credit Facility [Line Items]
Commitment fees, percentage				0.35%