Consolidated Statements Of Shareholders' Equity - 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			(519)
Treasury Stock, Retired, Cost Method, Amount		0	0		0
Net shares redeemed under employee share-based compensation plans			262	(187)
Exercise of stock options				(24)
Share-based compensation expense				66
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(352)
Net income (loss)	$ 2,300				2,300
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 benefit of $834 and $401						(1,892)
Amounts reclassified from AOCI, net of income tax (expense) benefit of $(22) and $4						(20)
Change in period, net of income tax benefit of $812 and $405						(1,912)
Change in period, net of income tax benefit of $4 and $2							24
Change in period, net of income tax (expense) benefit of $(4) and $5								(23)
Balance - end of period at Mar. 31, 2021	59,076	11,064	(3,901)	9,318	41,637	2,761	(1,613)	(190)	$ 958
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			(1,001)
Treasury Stock, Retired, Cost Method, Amount		(319)	2,510		(2,191)
Net shares redeemed under employee share-based compensation plans			255	(199)
Exercise of stock options				(21)
Share-based compensation expense				70
Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings				(340)
Net income (loss)	1,974				1,974
Funding of dividends declared from Additional paid-in capital					340
Dividends declared on Common Shares					(340)
Change in period, before reclassification from AOCI, net of income tax benefit of $834 and $401						(3,954)
Amounts reclassified from AOCI, net of income tax (expense) benefit of $(22) and $4						114
Change in period, net of income tax benefit of $812 and $405						(3,840)
Change in period, net of income tax benefit of $4 and $2							71
Change in period, net of income tax (expense) benefit of $(4) and $5								15
Balance - end of period at Mar. 31, 2022	$ 56,698	$ 10,666	$ (5,700)	$ 7,988	$ 47,148	$ (1,584)	$ (2,075)	$ 255	$ (3,404)