Medical Claims Payable (Reconciliation Of The Beginning And Ending Balances For Medical Claims Payable) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Medical Claims Payable [Line Items]
Gross medical claims payable, beginning of year	$ 13,282	$ 11,135	$ 8,647
Ceded medical claims payable, beginning of year	(21)	(46)	(33)
Net medical claims payable, beginning of year	13,261	11,089	8,614
Business combinations and purchase adjustments	133	420	339
Current Year Claims and Claims Adjustment Expense	113,414	100,440	85,094
Net incurred medical claims in prior years redundancies	(869)	(1,703)	(637)
Total net incurred medical claims	112,545	98,737	84,457
Net payments attributable to current year medical claims	98,997	88,156	74,629
Net payments attributable to prior years medical claims	11,600	8,829	7,692
Total net payments	110,597	96,985	82,321
Net medical claims payable, end of year	15,342	13,261	11,089
Ceded medical claims payable, end of year	6	21	46
Gross medical claims payable, end of year	15,348	13,282	11,135
Commercial and Specialty Business Segment [Member]
Medical Claims Payable [Line Items]
Gross medical claims payable, beginning of year	3,847	3,294	3,039
Ceded medical claims payable, beginning of year	(13)	(13)	(14)
Net medical claims payable, beginning of year	3,834	3,281	3,025
Business combinations and purchase adjustments	3	0
Current Year Claims and Claims Adjustment Expense	30,067	28,132	24,894
Net incurred medical claims in prior years redundancies	(154)	(465)	(375)
Total net incurred medical claims	29,913	27,667	24,519
Net payments attributable to current year medical claims	26,274	24,502	21,736
Net payments attributable to prior years medical claims	3,362	2,612	2,527
Total net payments	29,636	27,114	24,263
Net medical claims payable, end of year	4,114	3,834	3,281
Ceded medical claims payable, end of year	5	13	13
Gross medical claims payable, end of year	4,119	3,847	3,294
Government Business Segment [Member]
Medical Claims Payable [Line Items]
Gross medical claims payable, beginning of year	9,157	7,646	5,608
Ceded medical claims payable, beginning of year	(8)	(33)	(19)
Net medical claims payable, beginning of year	9,149	7,613	5,589
Business combinations and purchase adjustments	130	375	141
Current Year Claims and Claims Adjustment Expense	81,795	70,670	58,912
Net incurred medical claims in prior years redundancies	(630)	(1,222)	(262)
Total net incurred medical claims	81,165	69,448	58,650
Net payments attributable to current year medical claims	71,463	62,233	51,602
Net payments attributable to prior years medical claims	8,052	6,054	5,165
Total net payments	79,515	68,287	56,767
Net medical claims payable, end of year	10,929	9,149	7,613
Ceded medical claims payable, end of year	1	8	33
Gross medical claims payable, end of year	10,930	9,157	7,646
Other Segment [Member]
Medical Claims Payable [Line Items]
Gross medical claims payable, beginning of year	278	195	0
Ceded medical claims payable, beginning of year	0	0	0
Net medical claims payable, beginning of year	278	195	0
Business combinations and purchase adjustments	0	45	198
Current Year Claims and Claims Adjustment Expense	1,552	1,638	1,288
Net incurred medical claims in prior years redundancies	(85)	(16)	0
Total net incurred medical claims	1,467	1,622	1,288
Net payments attributable to current year medical claims	1,260	1,421	1,291
Net payments attributable to prior years medical claims	186	163	0
Total net payments	1,446	1,584	1,291
Net medical claims payable, end of year	299	278	195
Ceded medical claims payable, end of year	0	0	0
Gross medical claims payable, end of year	$ 299	$ 278	$ 195