Lease Costs and Other Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Lease cost
Operating lease cost	$ 12
Variable lease cost	9
Total lease cost	21
Other information
Operating cash flows used for operating leases	$ 12
Weighted-average remaining lease term - operating leases	45 years
Weighted-average discount rate - operating leases	5.40%