Leases (Schedule of Leasing Activity) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 54
Short-term lease cost	121
Total lease cost	175
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	56
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 20
Weighted-average remaining lease term-operating (in years)	8 years
Weighted-average discount rate-operating leases	7.60%