Employee Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Accrued expenses		$ (41)		$ (45)
Other long-term liabilities		(601)		(878)
Pension Plans [Member]
Changes in benefit obligation
Benefit obligation as of beginning of year		3,625	[1]	3,239
Service cost		161		140		$ 119
Interest cost		73		85		98
Participant contributions		0		0
Benefits paid		(284)		(195)
Actuarial (gain) loss		(111)		339
Other		(1)		17
Benefit obligation as of end of year		3,463	[1]	3,625	[1]	3,239
Changes in plan assets
Fair value of plan assets as of beginning of year	[1]	3,067		2,709
Actual return on plan assets	[1]	389		413
Company contributions	[1]	135		129
Participant contributions	[1]	0		0
Benefits paid	[1]	(284)		(195)
Other	[1]	(4)		11
Fair value of plan assets as of end of year	[1]	3,303		3,067		$ 2,709
Reconciliation of funded status:
Funded status as of end of year	[1]	(160)		(558)
Accumulated benefit obligation		$ 3,238		$ 3,398
Actuarial Gain (Loss), Discount Rates (Textual)
Discount rate		2.93%		2.62%		3.14%
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Deferred charges and other assets, net		$ 135		$ 7
Accrued expenses		(19)		(24)
Other long-term liabilities		(276)		(541)
Amounts recognized in balance sheet for defined benefit plans		(160)		(558)
Other Postretirement Benefit Plans [Member]
Changes in benefit obligation
Benefit obligation as of beginning of year		358	[1]	336
Service cost		7		6		$ 5
Interest cost		7		9		11
Participant contributions		13		12
Benefits paid		(29)		(28)
Actuarial (gain) loss		(9)		23
Other		0		0
Benefit obligation as of end of year		347	[1]	358	[1]	336
Changes in plan assets
Fair value of plan assets as of beginning of year	[1]	0		0
Actual return on plan assets	[1]	0		0
Company contributions	[1]	16		16
Participant contributions	[1]	13		12
Benefits paid	[1]	(29)		(28)
Other	[1]	0		0
Fair value of plan assets as of end of year	[1]	0		0		$ 0
Reconciliation of funded status:
Funded status as of end of year	[1]	$ (347)		$ (358)
Actuarial Gain (Loss), Discount Rates (Textual)
Discount rate		2.96%		2.64%
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Deferred charges and other assets, net		$ 0		$ 0
Accrued expenses		(22)		(21)
Other long-term liabilities		(325)		(337)
Amounts recognized in balance sheet for defined benefit plans		$ (347)		$ (358)

[1] Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 20 for the assets associated with certain U.S. nonqualified pension plans.