Consolidated Statements of Shareholders' Equity (Parentheticals) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2020	Jan. 01, 2018
Treasury shares held in trust (in shares)	1	1			1
Treasury shares held in trust	$ 29	$ 29			$ 29
Common stock	17	17			17
Cumulative adjustment to retained earnings as a result of new accounting standard adoption	64,170	$ 58,543		$ 37,695	69,701
Decrease to accumulated other comprehensive income	(1,019)				(1,414)
Increase to retained earnings	$ 45,108				49,640
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201602Member
Accounting Standards Update 2014-09
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201409Member
Accounting Standards Update 2018-02
Decrease to accumulated other comprehensive income						$ 7
Increase to retained earnings						7
Accounting Standards Update [Extensible List]				us-gaap:AccountingStandardsUpdate201802Member
Retained Earnings
Cumulative adjustment to retained earnings as a result of new accounting standard adoption	$ 45,108	$ 40,911		$ 43,556	$ 49,640
Cumulative Effect, Period of Adoption, Adjustment
Cumulative adjustment to retained earnings as a result of new accounting standard adoption	(3)	178	[1]	(13)
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings
Cumulative adjustment to retained earnings as a result of new accounting standard adoption	$ (3)	$ 178	[1]	$ (6)
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings | Accounting Standards Update 2018-02
Cumulative adjustment to retained earnings as a result of new accounting standard adoption						$ 13

[1] Reflects the adoption of Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which resulted in a reduction to retained earnings of $13 million and the adoption of ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which resulted in a reduction to accumulated other comprehensive income of $7 million and an increase to retained earnings of $7 million, each during the year ended December 31, 2018.(4)Reflects the adoption of ASU 2016-02, Leases (Topic 842), which resulted in an increase to retained earnings of $178 million during the year ended December 31, 2019.