Total Equity - Cumulative Adjustments to Retained Earnings Related to the Adoption of Accounting Updates (Details) - Retained Earnings - USD ($) $ in Millions		Jul. 01, 2019	Jan. 01, 2019	Jul. 01, 2018	Jan. 01, 2018
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes	[1]	$ 0	$ 63	$ 0	$ 306
Accounting Standards Update 2018-11
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes			$ 63
Accounting Standards Update 2014-09
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes					(32)
Accounting Standards Update 2017-12
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes					(99)
Accounting Standards Update 2018-02
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes					443
Accounting Standards Update, Others
Retained Earnings Adjustments [Line Items]
Cumulative adjustments for accounting changes					$ (6)

[1] Cumulative adjustments for accounting changes relate to the adoption of certain accounting updates during the current and prior year periods. See Notes 2 and 14 for further information.