Income Taxes (Narrative) (Details) $ / shares in Units, $ in Millions, kr in Billions		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2021 USD ($) $ / shares	Dec. 31, 2021 DKK (kr)	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2017	Dec. 31, 2018 USD ($)
Net deferred tax liabilities		$ (3,563)		$ (3,454)
Valuation allowance, deferred tax asset, change in amount		(22)
Basis differences in investments outside the U.S.		$ 11,200
Statutory federal income tax rate	21.00%	21.00%	21.00%	21.00%	21.00%	35.00%
Effective income tax rate		16.50%	16.50%	18.90%	26.40%
Effective income tax rate reconciliation, other reconciling items, percent		3.50%	3.50%	0.70%	6.50%
Income tax payments		$ 1,700		$ 1,100	$ 847
Employee service share-based compensation, tax benefit from exercise of stock options		118		110	79
Excess tax benefit from share-based compensation, operating activities		95		85	55
Net operating loss carryforwards		427
Operating loss carryforwards, valuation allowances		172
Deferred tax assets, valuation allowances		242		264
Gross unrecognized tax benefits		1,095		1,175	1,181		$ 986
Unrecognized tax benefits, net of offsetting indirect tax benefits		1,200		1,400
Unrecognized tax benefits, indirect tax benefits		58		148
Potential interest and penalties		(163)		(354)
Recognized potential interest and penalties		182		41	227
Unrecognized tax benefits that would impact effective tax rate		1,100		1,400
Estimated reduction in unrecognized tax benefits within twelve months		(58)
General business and foreign tax credit
Tax credit carryforwards		117
Tax credit carryforward, valuation allowance		58
Deferred tax asset, other
Deferred tax assets, valuation allowances		12
Domestic tax authority | IRS
Proposed adjustments to taxable income, self-insurance, other				2,700
Foreign tax authority
Income tax examination, amount of tax assessments 2010-2015		317	kr 2.1
Income tax holiday, aggregate dollar amount		$ 59		$ 43	$ 71
Income tax holiday, income tax benefits per diluted common share | $ / shares		$ 0.08		$ 0.06	$ 0.10
United States
Net deferred tax liabilities		$ (2,100)		$ (1,900)
Non-U.S.
Net deferred tax liabilities		$ (1,500)		$ (1,600)