Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017
Income Tax Contingency [Line Items]
Deferred Tax Liabilities, Net	$ 1,897	$ 2,702
Income tax expense	$ 1,750	$ 1,830	$ 1,666
Income tax expense (benefit) per diluted share	$ 7.21	$ 7.41	$ 6.55
Effective Income Tax Reconciliation Patient Protection Affordable Care Act Health Insurance Provider Fee	$ 0	$ 0	$ 330
Unrecognized tax benefits that would impact effective tax rate in future periods, if recognized	328	250
Unrecognized tax benefits that would impact additional paid-in capital in future periods, if recognized	2
Protective state income tax refund claims filed	92			$ 310
Net interest expense (benefit)	13	9	7
Interest accrued	55	42
Income Taxes Receivable	440	173
Income Taxes Paid	1,594	1,299	$ 1,790
Minimum [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefit change reasonably possible due to tax settlements - lower amount	33
Maximum [Member]
Income Tax Contingency [Line Items]
Unrecognized tax benefit change reasonably possible due to tax settlements - lower amount	143
Health Insurance Provider fee [Member]
Income Tax Contingency [Line Items]
Income tax expense (benefit) per diluted share			$ 1.30
Effective Income Tax Reconciliation Patient Protection Affordable Care Act Health Insurance Provider Fee			$ 330
Indefinite Carryforward Period | Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carry forwards	109
Limited Carryforward Period | Federal [Member]
Income Tax Contingency [Line Items]
Net operating loss carry forwards	$ 160
Earliest Tax Year [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2032
Earliest Tax Year [Member] | State [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Jan. 01, 2023
Latest Tax Year [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2042
Latest Tax Year [Member] | State [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2042
Other Noncurrent Assets [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Net	$ 137	103
Deferred tax liabilities, net [Member]
Income Tax Contingency [Line Items]
Deferred Tax Liabilities, Net	$ 2,034	$ 2,805