Leases - Additional Information (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Lease cost:
Amortization of ROU assets	$ 2	$ 6
Interest on lease liability	0	1
Finance lease cost	2	7
Operating lease cost	7	24
Short-term lease cost	34	82
Total lease cost	43	113
Other information:
Operating cash outflows from finance lease	0	1
Operating cash outflows from operating leases	3	8
Investing cash outflows from operating leases	38	98
Financing cash outflows from finance lease	$ 2	$ 6
Weighted-average remaining lease term - finance lease	2 years 3 months	2 years 3 months
Weighted-average remaining lease term - operating leases	4 years 10 months 13 days	4 years 10 months 13 days
Weighted-average discount rate - finance lease	7.50%	7.50%
Weighted-average discount rate - operating leases	4.17%	4.17%
Capitalized lease costs	$ 38	$ 98