SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Premiums	$ 28,142	$ 25,495	$ 56,403	$ 51,045
Services revenue	1,100	978	2,162	1,977
Total revenues	29,540	26,747	59,151	53,489
Investment income	298	274	586	467
Benefits	25,039	22,009	50,163	43,867
Operating costs	3,148	3,111	6,190	6,090
Depreciation and amortization	212	191	421	377
Total operating expenses	28,399	25,311	56,774	50,334
Income from operations	1,141	1,436	2,377	3,155
Interest expense	168	120	327	233
Other expense (income), net	55	54	118	46
Income (loss) before income taxes and equity in net losses	918	1,262	1,932	2,876
Equity in net earnings (losses)	(17)	(10)	(41)	(27)
Segment earnings (loss)	901	1,252	1,891	2,849
Net loss attributable to noncontrolling interests	1	3	3	4
Segment earnings (loss) attributable to Humana	902	1,255	1,894	2,853
Products
Segment Reporting Information [Line Items]
Premiums	28,142	25,495	56,403	51,045
Products | Total Medicare
Segment Reporting Information [Line Items]
Premiums	25,020	22,049	50,278	44,239
Products | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	22,215	19,749	44,663	39,558
Products | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,938	1,732	3,927	3,497
Products | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	867	568	1,688	1,184
Products | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	152	950	408	1,968
Products | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	240	252	479	506
Products | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	206	182	403	361
Products | State-based contracts and other
Segment Reporting Information [Line Items]
Premiums	2,524	2,062	4,835	3,971
Services
Segment Reporting Information [Line Items]
Services revenue	1,100	978	2,162	1,977
Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue	335	341	670	655
Services | Primary care
Segment Reporting Information [Line Items]
Services revenue	322	190	563	391
Services | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	8	64	32	135
Services | Military services and other
Segment Reporting Information [Line Items]
Services revenue	206	167	457	338
Services | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	229	216	440	458
Total external revenues
Segment Reporting Information [Line Items]
Total revenues	29,242	26,473	58,565	53,022
Operating segments | Insurance
Segment Reporting Information [Line Items]
Total revenues	28,525	25,875	57,224	51,778
Investment income	168	134	330	231
Benefits	25,182	22,127	50,433	44,120
Operating costs	2,395	2,545	4,759	4,963
Depreciation and amortization	185	172	371	337
Total operating expenses	27,762	24,844	55,563	49,420
Income from operations	763	1,031	1,661	2,358
Interest expense	0	0	0	0
Other expense (income), net	0	0	0	0
Income (loss) before income taxes and equity in net losses	763	1,031	1,661	2,358
Equity in net earnings (losses)	1	1	(1)	(2)
Segment earnings (loss)	764	1,032	1,660	2,356
Net loss attributable to noncontrolling interests	1	3	3	4
Segment earnings (loss) attributable to Humana	765	1,035	1,663	2,360
Operating segments | Insurance | Products
Segment Reporting Information [Line Items]
Premiums	28,142	25,495	56,403	51,045
Operating segments | Insurance | Products | Total Medicare
Segment Reporting Information [Line Items]
Premiums	25,020	22,049	50,278	44,239
Operating segments | Insurance | Products | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	22,215	19,749	44,663	39,558
Operating segments | Insurance | Products | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,938	1,732	3,927	3,497
Operating segments | Insurance | Products | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	867	568	1,688	1,184
Operating segments | Insurance | Products | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	152	950	408	1,968
Operating segments | Insurance | Products | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	240	252	479	506
Operating segments | Insurance | Products | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	206	182	403	361
Operating segments | Insurance | Products | State-based contracts and other
Segment Reporting Information [Line Items]
Premiums	2,524	2,062	4,835	3,971
Operating segments | Insurance | Services
Segment Reporting Information [Line Items]
Services revenue	214	231	489	473
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	8	64	32	135
Operating segments | Insurance | Services | Military services and other
Segment Reporting Information [Line Items]
Services revenue	206	167	457	338
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	28,356	25,726	56,892	51,518
Operating segments | CenterWell
Segment Reporting Information [Line Items]
Total revenues	4,947	4,530	9,765	9,035
Investment income	0	0	0	0
Benefits	0	0	0	0
Operating costs	4,553	4,193	9,036	8,319
Depreciation and amortization	56	50	109	99
Total operating expenses	4,609	4,243	9,145	8,418
Income from operations	338	287	620	617
Interest expense	1	1	2	1
Other expense (income), net	0	0	0	0
Income (loss) before income taxes and equity in net losses	337	286	618	616
Equity in net earnings (losses)	(18)	(11)	(40)	(25)
Segment earnings (loss)	319	275	578	591
Net loss attributable to noncontrolling interests	0	0	0	0
Segment earnings (loss) attributable to Humana	319	275	578	591
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	886	747	1,673	1,504
Operating segments | CenterWell | Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue	335	341	670	655
Operating segments | CenterWell | Services | Primary care
Segment Reporting Information [Line Items]
Services revenue	322	190	563	391
Operating segments | CenterWell | Services | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell | Services | Military services 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	229	216	440	458
Operating segments | CenterWell | Total external revenues
Segment Reporting Information [Line Items]
Total revenues	886	747	1,673	1,504
Eliminations/ Corporate
Segment Reporting Information [Line Items]
Total revenues	(3,932)	(3,658)	(7,838)	(7,324)
Investment income	130	140	256	236
Benefits	(143)	(118)	(270)	(253)
Operating costs	(3,800)	(3,627)	(7,605)	(7,192)
Depreciation and amortization	(29)	(31)	(59)	(59)
Total operating expenses	(3,972)	(3,776)	(7,934)	(7,504)
Income from operations	40	118	96	180
Interest expense	167	119	325	232
Other expense (income), net	55	54	118	46
Income (loss) before income taxes and equity in net losses	(182)	(55)	(347)	(98)
Equity in net earnings (losses)	0	0	0	0
Segment earnings (loss)	(182)	(55)	(347)	(98)
Net loss attributable to noncontrolling interests	0	0	0	0
Segment earnings (loss) attributable to Humana	(182)	(55)	(347)	(98)
Eliminations/ Corporate | Insurance
Segment Reporting Information [Line Items]
Total revenues	1	15	2	29
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	15	2	29
Eliminations/ Corporate | CenterWell
Segment Reporting Information [Line Items]
Total revenues	4,061	3,783	8,092	7,531
Eliminations/ Corporate | CenterWell | Products
Segment Reporting Information [Line Items]
Total revenues	2,645	2,639	5,262	5,254
Eliminations/ Corporate | CenterWell | Services
Segment Reporting Information [Line Items]
Total revenues	1,416	1,144	2,830	2,277
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues	(4,062)	(3,798)	(8,094)	(7,560)
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Total revenues	(2,645)	(2,639)	(5,262)	(5,254)
Intersegment Eliminations | Services
Segment Reporting Information [Line Items]
Total revenues	$ (1,417)	$ (1,159)	$ (2,832)	$ (2,306)