Consolidated Statements Of Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock [Member]	Common shares in treasury [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]	Cumulative Foreign Currency Translation Adjustment [Member]	Postretirement Benefit Liability Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance - beginning of period at Dec. 31, 2020		$ 11,064	$ (3,644)	$ 9,815	$ 39,337	$ 4,673	$ (1,637)	$ (167)
Common Shares repurchased			(2,440)
Treasury Stock, Retired, Cost Method, Amount		0	0		0
Net shares redeemed under employee share-based compensation plans			312	(182)
Exercise of stock options				(30)
Share-based compensation expense				147
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(704)
Net income (loss)	$ 4,565				4,565
Funding of dividends declared from Additional paid-in capital					704
Dividends declared on Common Shares					(704)
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $292, $(107), $1,126, and $294						(1,293)
Amounts reclassified from AOCI, net of income tax expense of $(77), $(6), $(99), and $(2)						(38)
Change in period, net of income tax (expense) benefit of $215, $(113), $1,027, and $292						(1,331)
Change in period, net of income tax (expense) benefit of $31, $(18), $35, and $(16)							314
Change in period, net of income tax (expense) benefit of $(1), $2, $(5), and $7								(30)
Balance - end of period at Jun. 30, 2021	60,062	11,064	(5,772)	9,046	43,902	3,342	(1,323)	(197)	$ 1,822
Balance - beginning of period at Mar. 31, 2021		11,064	(3,901)	9,318	41,637	2,761	(1,613)	(190)
Common Shares repurchased			(1,921)
Treasury Stock, Retired, Cost Method, Amount		0	0		0
Net shares redeemed under employee share-based compensation plans			50	5
Exercise of stock options				(6)
Share-based compensation expense				81
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(352)
Net income (loss)	2,265				2,265
Funding of dividends declared from Additional paid-in capital					352
Dividends declared on Common Shares					(352)
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $292, $(107), $1,126, and $294						599
Amounts reclassified from AOCI, net of income tax expense of $(77), $(6), $(99), and $(2)						(18)
Change in period, net of income tax (expense) benefit of $215, $(113), $1,027, and $292						581
Change in period, net of income tax (expense) benefit of $31, $(18), $35, and $(16)							290
Change in period, net of income tax (expense) benefit of $(1), $2, $(5), and $7								(7)
Balance - end of period at Jun. 30, 2021	60,062	11,064	(5,772)	9,046	43,902	3,342	(1,323)	(197)	1,822
Balance - beginning of period at Dec. 31, 2021	59,714	10,985	(7,464)	8,478	47,365	2,256	(2,146)	240
Common Shares repurchased			(2,130)
Treasury Stock, Retired, Cost Method, Amount		(319)	2,510		(2,191)
Net shares redeemed under employee share-based compensation plans			290	(195)
Exercise of stock options				(27)
Share-based compensation expense				139
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(688)
Net income (loss)	3,189				3,189
Funding of dividends declared from Additional paid-in capital					688
Dividends declared on Common Shares					(688)
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $292, $(107), $1,126, and $294						(8,448)
Amounts reclassified from AOCI, net of income tax expense of $(77), $(6), $(99), and $(2)						479
Change in period, net of income tax (expense) benefit of $215, $(113), $1,027, and $292						(7,969)
Change in period, net of income tax (expense) benefit of $31, $(18), $35, and $(16)							(675)
Change in period, net of income tax (expense) benefit of $(1), $2, $(5), and $7								19
Balance - end of period at Jun. 30, 2022	51,667	10,666	(6,794)	7,707	48,363	(5,713)	(2,821)	259	(8,275)
Balance - beginning of period at Mar. 31, 2022		10,666	(5,700)	7,988	47,148	(1,584)	(2,075)	255
Common Shares repurchased			(1,129)
Treasury Stock, Retired, Cost Method, Amount		0	0		0
Net shares redeemed under employee share-based compensation plans			35	4
Exercise of stock options				(6)
Share-based compensation expense				69
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(348)
Net income (loss)	1,215				1,215
Funding of dividends declared from Additional paid-in capital					348
Dividends declared on Common Shares					(348)
Change in period, before reclassification from AOCI, net of income tax (expense) benefit of $292, $(107), $1,126, and $294						(4,494)
Amounts reclassified from AOCI, net of income tax expense of $(77), $(6), $(99), and $(2)						365
Change in period, net of income tax (expense) benefit of $215, $(113), $1,027, and $292						(4,129)
Change in period, net of income tax (expense) benefit of $31, $(18), $35, and $(16)							(746)
Change in period, net of income tax (expense) benefit of $(1), $2, $(5), and $7								4
Balance - end of period at Jun. 30, 2022	$ 51,667	$ 10,666	$ (6,794)	$ 7,707	$ 48,363	$ (5,713)	$ (2,821)	$ 259	$ (8,275)