Income Taxes - Schedule of Expiration Periods of Deferred Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Tax Credit Carryforward [Line Items]
Tax loss carryforwards	$ 2,932
Tax credit carryforwards	379
Other	1,208
Valuation allowance	(2,256)	$ (2,486)	$ (2,584)	$ (1,940)
Deferred tax assets, net	2,263	$ 2,336
Expires within 10 years
Tax Credit Carryforward [Line Items]
Tax loss carryforwards	452
Tax credit carryforwards	300
Other	0
Valuation allowance	(711)
Deferred tax assets, net	41
Expires within 11-20 years
Tax Credit Carryforward [Line Items]
Tax loss carryforwards	235
Tax credit carryforwards	69
Other	0
Valuation allowance	(176)
Deferred tax assets, net	128
No expiration
Tax Credit Carryforward [Line Items]
Tax loss carryforwards	2,245
Tax credit carryforwards	10
Other	120
Valuation allowance	(1,306)
Deferred tax assets, net	1,069
Other(2)
Tax Credit Carryforward [Line Items]
Tax loss carryforwards	0
Tax credit carryforwards	0
Other	1,088
Valuation allowance	(63)
Deferred tax assets, net	$ 1,025