Long-Term Debt - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Nov. 02, 2020	Mar. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Principal amount	$ 765,000,000		$ 765,000,000				$ 765,000,000
Weighted average interest rate	3.30%	4.10%	3.20%	4.10%
Minimum
Debt Instrument [Line Items]
Interest rate margin			2.50%
Revolving credit facility interest rate percent above LIBOR alternate interest rate			1.50%
Commitment fee percentage	0.50%		0.50%
Maximum
Debt Instrument [Line Items]
Interest rate margin			3.50%
Revolving credit facility interest rate percent above LIBOR alternate interest rate			2.50%
Amended Credit Facility
Debt Instrument [Line Items]
Debt instrument, maturity date			Sep. 14, 2023
Line of credit facility, maximum borrowing capacity	$ 300,000,000.0		$ 300,000,000.0			$ 500,000,000.0
Principal amount	140,000,000.0		140,000,000.0				$ 140,000,000
Letters of credit issued amount	22,300,000		22,300,000
Line of credit facility, remaining borrowing capacity	87,700,000		87,700,000
Permitted Debt Resulting in Accelerated Maturity Date	100,000,000.0		100,000,000.0
Line of Credit Facility, Required Availability under the Credit Facility	50,000,000.0		50,000,000.0
Line of Credit Facility, Maximum Weekly Cash Balance	$ 35,000,000.0		$ 35,000,000.0
Amended Credit Facility | Subsequent Event [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 185,000,000.0
LineOfCreditFacilityBorrowingBase,LimitedByElectedCommitments					$ 200,000,000.0