Long-Term Debt - Components of Long-Term Debt (Parenthetical) (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019	Jun. 24, 2020	Feb. 16, 2016	Sep. 21, 2015	Feb. 11, 2015	Jul. 01, 2014	Mar. 12, 2013
6.125% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	6.125%	6.125%						6.125%
Senior notes maturity year	2021	2021
5.125% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	5.125%	5.125%					5.125%
Senior notes maturity year	2022	2022
5.625% Senior Notes Due 2023 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	5.625%	5.625%			5.625%	5.625%
Senior notes maturity year	2023	2023
6.500% Senior Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	6.50%	6.50%		6.50%
Senior notes maturity year	2024	2024
5.500% Senior Notes due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	5.50%	5.50%	5.50%
Senior notes maturity year	2028	2028