Leases (Other information related to operating leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Cash paid for amounts included in the measurement of operating lease liabilities	$ 243	$ 250	$ 218
Right-of-use assets obtained in exchange for new operating lease obligations	$ 271	$ 182	$ 239