Leases - Summary of Other Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases Operating [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 11
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 3
Weighted-average remaining lease term: - operating leases	7 years
Weighted-average discount rate: - operating leases	2.70%