Goodwill and Intangible Assets - Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Changes in the carrying amount of goodwill
Balance at the beginning of the period	$ 15,663,000,000	$ 15,785,000,000
Foreign currency translation	(59,000,000)	(122,000,000)
Balance at the end of the period	15,604,000,000	$ 15,663,000,000
Accumulated goodwill impairment losses
Accumulated goodwill impairment losses	$ 0