SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Premiums	$ 25,495	$ 22,266	$ 51,045	$ 44,969
Services revenue	978	1,349	1,977	2,613
Total revenues	26,747	23,662	53,489	47,632
Investment income (loss)	274	47	467	50
Benefits	22,009	19,099	43,867	38,724
Operating costs	3,111	3,173	6,090	6,059
Depreciation and amortization	191	175	377	345
Total operating expenses	25,311	22,447	50,334	45,128
Income (loss) from operations	1,436	1,215	3,155	2,504
Interest expense	120	101	233	191
Other expense (income), net	54	(8)	46	(29)
Income before income taxes and equity in net losses	1,262	1,122	2,876	2,342
Equity in net earnings (losses)	(10)	2	(27)	(2)
Segment earnings (loss)	1,252	1,124	2,849	2,340
Net (income) loss attributable to noncontrolling interests	3	(1)	4	(1)
Segment earnings (loss) attributable to Humana	1,255	1,123	2,853	2,339
Insurance
Segment Reporting Information [Line Items]
Total revenues	25,875	22,532	51,778	45,499
Investment income (loss)	134	46	231	92
Total operating expenses	24,844	21,425	49,420	43,396
CenterWell
Segment Reporting Information [Line Items]
Total revenues	4,530	4,527	9,035	8,892
Investment income (loss)	0	1	0	3
Total operating expenses	4,243	4,169	8,418	8,164
Operating segments
Segment Reporting Information [Line Items]
Premiums	25,495	22,266	51,045	44,969
Services revenue	978	1,349	1,977	2,613
Total revenues	26,473	23,615	53,022	47,582
Operating segments | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,749	16,692	39,558	33,744
Operating segments | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,732	1,857	3,497	3,732
Operating segments | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	568	606	1,184	1,245
Operating segments | Total Medicare
Segment Reporting Information [Line Items]
Premiums	22,049	19,155	44,239	38,721
Operating segments | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	950	1,109	1,968	2,249
Operating segments | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	252	261	506	522
Operating segments | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	182	185	361	367
Operating segments | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	2,062	1,556	3,971	3,110
Operating segments | Home solutions
Segment Reporting Information [Line Items]
Services revenue	341	752	655	1,478
Operating segments | Provider services
Segment Reporting Information [Line Items]
Services revenue	190	137	391	250
Operating segments | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	64	75	135	152
Operating segments | Military and other
Segment Reporting Information [Line Items]
Services revenue	167	131	338	258
Operating segments | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	216	254	458	475
Operating segments | Insurance
Segment Reporting Information [Line Items]
Premiums	25,495	22,266	51,045	44,969
Services revenue	231	206	473	410
Total revenues	25,726	22,472	51,518	45,379
Benefits	22,127	19,164	44,120	38,898
Operating costs	2,545	2,105	4,963	4,192
Depreciation and amortization	172	156	337	306
Income (loss) from operations	1,031	1,107	2,358	2,103
Interest expense	0	0	0	0
Other expense (income), net	0	0	0	0
Income before income taxes and equity in net losses	1,031	1,107	2,358	2,103
Equity in net earnings (losses)	1	8	(2)	8
Segment earnings (loss)	1,032	1,115	2,356	2,111
Net (income) loss attributable to noncontrolling interests	3	0	4	0
Segment earnings (loss) attributable to Humana	1,035	1,115	2,360	2,111
Operating segments | Insurance | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,749	16,692	39,558	33,744
Operating segments | Insurance | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,732	1,857	3,497	3,732
Operating segments | Insurance | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	568	606	1,184	1,245
Operating segments | Insurance | Total Medicare
Segment Reporting Information [Line Items]
Premiums	22,049	19,155	44,239	38,721
Operating segments | Insurance | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	950	1,109	1,968	2,249
Operating segments | Insurance | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	252	261	506	522
Operating segments | Insurance | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	182	185	361	367
Operating segments | Insurance | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	2,062	1,556	3,971	3,110
Operating segments | Insurance | Home solutions
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | Insurance | Provider services
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | Insurance | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	64	75	135	152
Operating segments | Insurance | Military and other
Segment Reporting Information [Line Items]
Services revenue	167	131	338	258
Operating segments | Insurance | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Services revenue	747	1,143	1,504	2,203
Total revenues	747	1,143	1,504	2,203
Benefits	0	0	0	0
Operating costs	4,193	4,125	8,319	8,073
Depreciation and amortization	50	44	99	91
Income (loss) from operations	287	358	617	728
Interest expense	1	0	1	0
Other expense (income), net	0	0	0	0
Income before income taxes and equity in net losses	286	358	616	728
Equity in net earnings (losses)	(11)	(6)	(25)	(10)
Segment earnings (loss)	275	352	591	718
Net (income) loss attributable to noncontrolling interests	0	(1)	0	(1)
Segment earnings (loss) attributable to Humana	275	351	591	717
Operating segments | CenterWell | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Total Medicare
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | CenterWell | Home solutions
Segment Reporting Information [Line Items]
Services revenue	341	752	655	1,478
Operating segments | CenterWell | Provider services
Segment Reporting Information [Line Items]
Services revenue	190	137	391	250
Operating segments | CenterWell | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell | Military and other
Segment Reporting Information [Line Items]
Services revenue	0	0	0	0
Operating segments | CenterWell | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue	216	254	458	475
Eliminations/ Corporate
Segment Reporting Information [Line Items]
Total revenues	(3,658)	(3,397)	(7,324)	(6,759)
Investment income (loss)	140	0	236	(45)
Benefits	(118)	(65)	(253)	(174)
Operating costs	(3,627)	(3,057)	(7,192)	(6,206)
Depreciation and amortization	(31)	(25)	(59)	(52)
Total operating expenses	(3,776)	(3,147)	(7,504)	(6,432)
Income (loss) from operations	118	(250)	180	(327)
Interest expense	119	101	232	191
Other expense (income), net	54	(8)	46	(29)
Income before income taxes and equity in net losses	(55)	(343)	(98)	(489)
Equity in net earnings (losses)	0	0	0	0
Segment earnings (loss)	(55)	(343)	(98)	(489)
Net (income) loss attributable to noncontrolling interests	0	0	0	0
Segment earnings (loss) attributable to Humana	(55)	(343)	(98)	(489)
Eliminations/ Corporate | Insurance
Segment Reporting Information [Line Items]
Total revenues	15	14	29	28
Eliminations/ Corporate | Insurance | Services
Segment Reporting Information [Line Items]
Total revenues	15	14	29	28
Eliminations/ Corporate | Insurance | Products
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Eliminations/ Corporate | CenterWell
Segment Reporting Information [Line Items]
Total revenues	3,783	3,383	7,531	6,686
Eliminations/ Corporate | CenterWell | Services
Segment Reporting Information [Line Items]
Total revenues	1,144	894	2,277	1,751
Eliminations/ Corporate | CenterWell | Products
Segment Reporting Information [Line Items]
Total revenues	2,639	2,489	5,254	4,935
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues	(3,798)	(3,397)	(7,560)	(6,714)
Intersegment Eliminations | Services
Segment Reporting Information [Line Items]
Total revenues	(1,159)	(908)	(2,306)	(1,779)
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Total revenues	$ (2,639)	$ (2,489)	$ (5,254)	$ (4,935)