Employee Benefit Plans (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021	Dec. 31, 2020
Components of Net Periodic Benefit Costs:
Defined benefit pension cost	$ (3,000,000)	$ 9,000,000	$ (5,000,000)	$ 46,000,000
Forecast
Contributions [Abstract]
Expected reduction in defined contribution plan expense					$ 20,000,000
Pension Plan
Contributions [Abstract]
Defined benefit plan, contributions by employer			102,000,000	97,000,000		$ 139,000,000
Defined benefit plan, expected future employer contributions	135,000,000		135,000,000
Pension Plan | U.S.
Components of Net Periodic Benefit Costs:
Service cost	0	0	1,000,000	1,000,000
Interest cost	19,000,000	21,000,000	56,000,000	65,000,000
Expected return on plan assets	(29,000,000)	(27,000,000)	(84,000,000)	(79,000,000)
Recognized net actuarial loss (gain)	4,000,000	6,000,000	13,000,000	20,000,000
Amortization of prior service credit	0	0	(1,000,000)	(1,000,000)
Recognized settlement loss	13,000,000	10,000,000	41,000,000	42,000,000
Recognized curtailment gain			0	0
Defined benefit pension cost	7,000,000	10,000,000	26,000,000	48,000,000
Defined contribution plans	0	(10,000,000)	0	1,000,000
Net Periodic Benefit Cost (Credit)	7,000,000	0	26,000,000	49,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial (gain) loss	(14,000,000)	77,000,000	(83,000,000)	(3,000,000)
Amortization of net actuarial loss	(17,000,000)	(16,000,000)	(54,000,000)	(62,000,000)
Amortization of net prior service credit	0	0	1,000,000	1,000,000
Total Recognized in Other Comprehensive (Loss) Income	(31,000,000)	61,000,000	(136,000,000)	(64,000,000)
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income	(24,000,000)	61,000,000	(110,000,000)	(15,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer			18,000,000	18,000,000		35,000,000
Defined benefit plan, expected future employer contributions	25,000,000		25,000,000
Pension Plan | U.S. | Qualified Plan
Contributions [Abstract]
Mandatory future contributions	0		0
Pension Plan | Non-U.S.
Components of Net Periodic Benefit Costs:
Service cost	5,000,000	5,000,000	15,000,000	15,000,000
Interest cost	23,000,000	29,000,000	67,000,000	84,000,000
Expected return on plan assets	(53,000,000)	(49,000,000)	(157,000,000)	(142,000,000)
Recognized net actuarial loss (gain)	15,000,000	15,000,000	44,000,000	43,000,000
Amortization of prior service credit	0	(1,000,000)	0	(1,000,000)
Recognized settlement loss	0	0	0	0
Recognized curtailment gain			0	(1,000,000)
Defined benefit pension cost	(10,000,000)	(1,000,000)	(31,000,000)	(2,000,000)
Defined contribution plans	5,000,000	6,000,000	15,000,000	16,000,000
Net Periodic Benefit Cost (Credit)	(5,000,000)	5,000,000	(16,000,000)	14,000,000
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial (gain) loss	0	0	1,000,000	0
Amortization of net actuarial loss	(15,000,000)	(15,000,000)	(44,000,000)	(43,000,000)
Amortization of net prior service credit	0	1,000,000	0	1,000,000
Total Recognized in Other Comprehensive (Loss) Income	(15,000,000)	(14,000,000)	(43,000,000)	(42,000,000)
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income	(20,000,000)	(9,000,000)	(59,000,000)	(28,000,000)
Contributions [Abstract]
Defined benefit plan, contributions by employer			84,000,000	79,000,000		104,000,000
Defined benefit plan, expected future employer contributions	110,000,000		110,000,000
Retiree Health
Components of Net Periodic Benefit Costs:
Service cost	0	1,000,000	1,000,000	2,000,000
Interest cost	2,000,000	2,000,000	6,000,000	8,000,000
Expected return on plan assets	0	0	0	0
Recognized net actuarial loss (gain)	0	0	0	(1,000,000)
Amortization of prior service credit	(16,000,000)	(19,000,000)	(49,000,000)	(57,000,000)
Recognized settlement loss	0	0	0	0
Recognized curtailment gain			0	0
Defined benefit pension cost	(14,000,000)	(16,000,000)	(42,000,000)	(48,000,000)
Net Periodic Benefit Cost (Credit)	(14,000,000)	(16,000,000)	(42,000,000)	(48,000,000)
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income:
Net actuarial (gain) loss	1,000,000	0	3,000,000	(6,000,000)
Amortization of net actuarial loss	0	0	0	1,000,000
Amortization of net prior service credit	16,000,000	19,000,000	49,000,000	57,000,000
Total Recognized in Other Comprehensive (Loss) Income	17,000,000	19,000,000	52,000,000	52,000,000
Total Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Loss) Income	3,000,000	$ 3,000,000	10,000,000	4,000,000
Contributions [Abstract]
Defined benefit plan, contributions by employer			17,000,000	$ 17,000,000		$ 25,000,000
Defined benefit plan, expected future employer contributions	$ 30,000,000		$ 30,000,000