Lease Obligations - Lessee (Other Information) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Other Information
Finance Lease Weighted Average Discount Rate, Percent	5.83%
Operating Lease Weighted Average Discount Rate, Percent	3.28%
Operating Lease Weighted Average Remaining Lease Term	9 years 1 month 2 days
Finance Lease Weighted Average Remaining Lease Term	4 years 7 months 2 days
Gains and losses on sale and leaseback transations, net	$ 0
Lease liability
Other Information
Operating Cash Flows from Operating Leases	21
Operating Cash Flows from Finance Leases	0
Financing Cash Flows from Finance Leases	$ 1