SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Premiums	$ 25,099	$ 21,468	$ 76,144	$ 66,437
Services revenue	1,016	1,159	2,993	3,772
Total revenues	26,423	22,799	79,912	70,431
Investment income	308	172	775	222
Benefits	21,745	18,384	65,612	57,108
Operating costs	3,271	3,061	9,361	9,120
Depreciation and amortization	201	182	578	527
Total operating expenses	25,217	21,627	75,551	66,755
Income (loss) from operations	1,206	1,172	4,361	3,676
Gain on sale of Gentiva Hospice	0	(240)	0	(240)
Interest expense	114	102	347	293
Other expense (income), net	(6)	13	40	(16)
Income (loss) before income taxes and equity in net losses	1,098	1,297	3,974	3,639
Equity in net earnings (losses)	(12)	3	(39)	1
Segment earnings (loss)	1,086	1,300	3,935	3,640
Net loss (income) attributable to noncontrolling interests	2	2	6	1
Segment earnings (loss) attributable to Humana	1,088	1,302	3,941	3,641
Products
Segment Reporting Information [Line Items]
Premiums	25,099	21,468	76,144	66,437
Products | Total Medicare
Segment Reporting Information [Line Items]
Premiums	21,825	18,333	66,064	57,054
Products | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,637	16,007	59,195	49,751
Products | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,695	1,792	5,192	5,524
Products | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	493	534	1,677	1,779
Products | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	842	1,075	2,810	3,324
Products | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	252	262	758	784
Products | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	185	188	546	555
Products | State-based contracts and other
Segment Reporting Information [Line Items]
Premiums	1,995	1,610	5,966	4,720
Services
Segment Reporting Information [Line Items]
Services revenue	1,016	1,159	2,993	3,772
Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue	342	519	997	1,997
Services | Primary care
Segment Reporting Information [Line Items]
Services revenue	214	159	605	409
Services | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	55	73	190	225
Services | Military and other
Segment Reporting Information [Line Items]
Services revenue	202	137	540	395
Services | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	203	271	661	746
Total external revenues
Segment Reporting Information [Line Items]
Total revenues	26,115	22,627	79,137	70,209
Operating segments | Insurance
Segment Reporting Information [Line Items]
Total revenues	25,511	21,743	77,289	67,242
Investment income	154	51	385	143
Benefits	21,976	18,413	66,096	57,311
Operating costs	2,634	2,294	7,597	6,486
Depreciation and amortization	179	163	516	469
Total operating expenses	24,789	20,870	74,209	64,266
Income (loss) from operations	722	873	3,080	2,976
Gain on sale of Gentiva Hospice		0		0
Interest expense	0	0	0	0
Other expense (income), net	0	0	0	0
Income (loss) before income taxes and equity in net losses	722	873	3,080	2,976
Equity in net earnings (losses)	0	8	(2)	16
Segment earnings (loss)	722	881	3,078	2,992
Net loss (income) attributable to noncontrolling interests	3	2	7	2
Segment earnings (loss) attributable to Humana	725	883	3,085	2,994
Operating segments | Insurance | Products
Segment Reporting Information [Line Items]
Premiums	25,099	21,468	76,144	66,437
Operating segments | Insurance | Products | Total Medicare
Segment Reporting Information [Line Items]
Premiums	21,825	18,333	66,064	57,054
Operating segments | Insurance | Products | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,637	16,007	59,195	49,751
Operating segments | Insurance | Products | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,695	1,792	5,192	5,524
Operating segments | Insurance | Products | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	493	534	1,677	1,779
Operating segments | Insurance | Products | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	842	1,075	2,810	3,324
Operating segments | Insurance | Products | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	252	262	758	784
Operating segments | Insurance | Products | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	185	188	546	555
Operating segments | Insurance | Products | State-based contracts and other
Segment Reporting Information [Line Items]
Premiums	1,995	1,610	5,966	4,720
Operating segments | Insurance | Services
Segment Reporting Information [Line Items]
Services revenue	257	210	730	620
Operating segments | Insurance | Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | Insurance | Services | Primary care
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | Insurance | Services | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	55	73	190	225
Operating segments | Insurance | Services | Military and other
Segment Reporting Information [Line Items]
Services revenue	202	137	540	395
Operating segments | Insurance | Services | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | Insurance | Total external revenues
Segment Reporting Information [Line Items]
Total revenues	25,356	21,678	76,874	67,057
Operating segments | CenterWell
Segment Reporting Information [Line Items]
Total revenues	4,660	4,274	13,695	13,166
Investment income	0	3	0	6
Benefits	0	0	0	0
Operating costs	4,207	3,929	12,526	12,002
Depreciation and amortization	53	45	152	136
Total operating expenses	4,260	3,974	12,678	12,138
Income (loss) from operations	400	300	1,017	1,028
Gain on sale of Gentiva Hospice		(240)		(240)
Interest expense	1	0	2	0
Other expense (income), net	0	0	0	0
Income (loss) before income taxes and equity in net losses	399	540	1,015	1,268
Equity in net earnings (losses)	(12)	(5)	(37)	(15)
Segment earnings (loss)	387	535	978	1,253
Net loss (income) attributable to noncontrolling interests	(1)	0	(1)	(1)
Segment earnings (loss) attributable to Humana	386	535	977	1,252
Operating segments | CenterWell | Products
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Total Medicare
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Products | State-based contracts and other
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Services
Segment Reporting Information [Line Items]
Services revenue	759	949	2,263	3,152
Operating segments | CenterWell | Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue	342	519	997	1,997
Operating segments | CenterWell | Services | Primary care
Segment Reporting Information [Line Items]
Services revenue	214	159	605	409
Operating segments | CenterWell | Services | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell | Services | Military and other
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell | Services | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	203	271	661	746
Operating segments | CenterWell | Total external revenues
Segment Reporting Information [Line Items]
Total revenues	759	949	2,263	3,152
Eliminations/ Corporate
Segment Reporting Information [Line Items]
Total revenues	(3,748)	(3,218)	(11,072)	(9,977)
Investment income	154	118	390	73
Benefits	(231)	(29)	(484)	(203)
Operating costs	(3,570)	(3,162)	(10,762)	(9,368)
Depreciation and amortization	(31)	(26)	(90)	(78)
Total operating expenses	(3,832)	(3,217)	(11,336)	(9,649)
Income (loss) from operations	84	(1)	264	(328)
Gain on sale of Gentiva Hospice		0		0
Interest expense	113	102	345	293
Other expense (income), net	(6)	13	40	(16)
Income (loss) before income taxes and equity in net losses	(23)	(116)	(121)	(605)
Equity in net earnings (losses)	0	0	0	0
Segment earnings (loss)	(23)	(116)	(121)	(605)
Net loss (income) attributable to noncontrolling interests	0	0	0	0
Segment earnings (loss) attributable to Humana	(23)	(116)	(121)	(605)
Eliminations/ Corporate | Insurance
Segment Reporting Information [Line Items]
Total revenues	1	14	30	42
Eliminations/ Corporate | Insurance | Products
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Eliminations/ Corporate | Insurance | Services
Segment Reporting Information [Line Items]
Total revenues	1	14	30	42
Eliminations/ Corporate | CenterWell
Segment Reporting Information [Line Items]
Total revenues	3,901	3,322	11,432	10,008
Eliminations/ Corporate | CenterWell | Products
Segment Reporting Information [Line Items]
Total revenues	2,594	2,459	7,848	7,394
Eliminations/ Corporate | CenterWell | Services
Segment Reporting Information [Line Items]
Total revenues	1,307	863	3,584	2,614
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues	(3,902)	(3,336)	(11,462)	(10,050)
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Total revenues	(2,594)	(2,459)	(7,848)	(7,394)
Intersegment Eliminations | Services
Segment Reporting Information [Line Items]
Total revenues	$ (1,308)	$ (877)	$ (3,614)	$ (2,656)