Debt - Summary of Financial Covenants (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Debt Disclosure [Abstract]
Minimum fixed charge coverage ratio, actual	2.47%
Maximum total leverage ratio, actual	2.50%
Minimum liquidity, actual	$ 1,140
Minimum fixed charge coverage ratio, requirement	1.50%
Maximum total leverage ratio, requirement	4.25%
Minimum liquidity, requirement	$ 200