Revenue Recognition - Disaggregation of Revenue by Geography (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Revenue by Geography
Revenues	$ 18,123	$ 19,161	$ 35,694	$ 37,342	$ 77,000
Americas
Revenue by Geography
Revenues	8,450	8,806	16,617	17,299
EMEA
Revenue by Geography
Revenues	5,695	6,149	11,212	11,876
Asia Pacific
Revenue by Geography
Revenues	$ 3,977	$ 4,205	$ 7,865	$ 8,167