Income Taxes (Deferred) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income taxes
Changes in valuation allowance	$ 1,167	$ (31)	$ 37
Deferred tax assets
Swiss historic depreciation and financing asset costs	1,333
Net operating loss carryforwards	915	809
Interest expense limitation	67	72
United Kingdom charter limitation	53	40
Accrued expenses	23	18
Tax credits	19	21
Deferred income	7	14
Accrued payroll expenses not currently deductible	2	46
Loss contingencies	2	3
Other	31	27
Valuation allowance	(1,820)	(685)
Total deferred tax assets	632	365
Deferred tax liabilities
Depreciation	(1,052)	(658)
Contract intangible amortization	(11)	(6)
Other	(9)	(7)
Total deferred tax liabilities	(1,072)	(671)
Deferred tax assets (liabilities), net	(440)	(306)
U.S. foreign tax credit carryforwards	19	21
NOLs that are not subject to expiration dates	668
NOLs that are subject to expiration dates	247
Reconciliation of unrecognized tax benefits, excluding interest and penalties
Balance, beginning of period	378	335	408
Additions for current year tax positions	28	90	144
Additions for prior year tax positions	46	11	6
Reductions related to statute of limitation expirations and changes in law	(19)	(7)	(138)
Reductions due to settlements	(31)		(19)
Reductions for prior year tax positions		(51)	(66)
Balance, end of period	402	378	335
Unrecognized tax benefits
Unrecognized tax benefits, excluding interest and penalties	402	378	335
Interest and penalties	33	41
Unrecognized tax benefits, including interest and penalties	435	419
Interest and penalties related to unrecognized tax benefits recognized as a component of income tax expense	8	$ 7	$ (72)
Unrecognized benefits netted against NOL deferred tax assets	320
Amount if recognized that would impact tax rate	115
Swiss TRAF
Income taxes
Changes in valuation allowance	1,170
Deferred tax assets
Total deferred tax assets	1,330
Deferred tax liabilities
Total deferred tax liabilities	$ (238)