Organizational Efficiency Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Restructuring and Related Activities [Abstract]
Charge for organizational efficiency plan, pre-tax	$ 31	$ 207	$ 31	$ 0
Charge for organizational efficiency plan, after-tax	$ 24	$ 162	$ 24	$ 0