Debt - Summary of Financial Covenants (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Debt Disclosure [Abstract]
Minimum fixed charge coverage ratio, actual	2.46%
Maximum total leverage ratio, actual	2.61%
Minimum liquidity, actual	$ 1,023
Minimum fixed charge coverage ratio, requirement	1.50%
Maximum total leverage ratio, requirement	4.25%
Minimum liquidity, requirement	$ 200