Postretirement benefits Schedule of Allocation of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Other Investments	$ 13,696		$ 11,169
Cash	2,012		1,659		$ 1,747
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	81		119		120
Fair Value, Recurring [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Other Investments	552	[1]	286	[2]
Fair Value, Recurring [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Other Investments	399	[1]	481	[2]
Fair Value, Recurring [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Other Investments	0	[1]	0	[2]
Other Investments
Defined Benefit Plan Disclosure [Line Items]
Other Investments	47		51
Other Investments | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	31
Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Investments	12,355		10,108
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	2,540	[3]	3,307	[4]
Defined Benefit Plan, Plan Assets, Amount	3,316		4,151		3,739
Cash	5		127
UNITED STATES | Pension Plan [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	1,798	[3]	2,287	[4]
UNITED STATES | Pension Plan [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	742	[3]	1,019	[4]
UNITED STATES | Pension Plan [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0	[3]	1	[4]
UNITED STATES | Pension Plan [Member] | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	42		33
UNITED STATES | Pension Plan [Member] | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	42		33
UNITED STATES | Pension Plan [Member] | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | U.S. Treasury / Agency
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	541		472
UNITED STATES | Pension Plan [Member] | U.S. Treasury / Agency | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	431		380
UNITED STATES | Pension Plan [Member] | U.S. Treasury / Agency | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	110		92
UNITED STATES | Pension Plan [Member] | U.S. Treasury / Agency | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Debt Security, Government, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	627		923
UNITED STATES | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	627		923
UNITED STATES | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | States, municipalities, and political subdivisions
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	5		4
UNITED STATES | Pension Plan [Member] | States, municipalities, and political subdivisions | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | States, municipalities, and political subdivisions | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	5		4
UNITED STATES | Pension Plan [Member] | States, municipalities, and political subdivisions | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	1,321		1,872
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	1,321		1,871
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		1
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Derivative
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	4		3
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Derivative | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	4		3
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Derivative | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Pension Plan [Member] | Defined Benefit Plan, Derivative | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
UNITED STATES | Other Investments | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Investments	538		542
UNITED STATES | Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Investments	233		175
Non - U.S. | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	721	[3]	1,128	[4]
Defined Benefit Plan, Plan Assets, Amount	938		1,318		$ 1,284
Non - U.S. | Pension Plan [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	117	[3]	158	[4]
Non - U.S. | Pension Plan [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	600	[3]	970	[4]
Non - U.S. | Pension Plan [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	4	[3]	0	[4]
Non - U.S. | Pension Plan [Member] | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	10		5
Non - U.S. | Pension Plan [Member] | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	10		5
Non - U.S. | Pension Plan [Member] | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
Non - U.S. | Pension Plan [Member] | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
Non - U.S. | Pension Plan [Member] | Debt Security, Government, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	454		679
Non - U.S. | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
Non - U.S. | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	454		679
Non - U.S. | Pension Plan [Member] | Debt Security, Government, Non-US [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	0		0
Non - U.S. | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	257		444
Non - U.S. | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 1
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	107		153
Non - U.S. | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 2
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	146		291
Non - U.S. | Pension Plan [Member] | Defined Benefit Plan, Equity Securities [Member] | Level 3
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, fair value of plan assets excluding measured using NAV	4		0
Non - U.S. | Other Investments | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Investments	201		175
Non - U.S. | Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Investments	$ 16		$ 15

[1] Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $12,355 million, policy loans of $343 million and other investments of $47 million at December 31, 2022 measured using NAV as a practical expedient

[2] Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $10,108 million, policy loans of $243 million and other investments of $51 million at December 31, 2021 measured using NAV as a practical expedient.

[3] Excluded from the table above are $538 million and $201 million of other investments related to the U.S. Plans and Non-U.S. Plans, respectively, limited partnerships of $233 million and $16 million in U.S. Plans and Non-U.S. Plans, respectively, measured using NAV as a practical expedient, and $5 million in cash and accrued income related to the U.S. Plans.

[4] Excluded from the table above are $542 million and $175 million of other investments related to the U.S. Plans and Non-U.S. Plans, respectively, limited partnerships of $175 million and $15 million in U.S. Plans and Non-U.S. Plans, respectively, measured using NAV as a practical expedient, and $127 million in cash and accrued income related to the U.S. Plans.