SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Premiums	$ 21,468	$ 19,885	$ 66,437	$ 59,987
Services revenue:	1,159	845	3,772	1,802
Total revenues	22,799	20,697	70,431	62,010
Investment income (loss)	172	(33)	222	221
Benefits	18,384	17,316	57,108	51,761
Operating costs	3,061	2,603	9,120	6,726
Depreciation and amortization	182	150	527	436
Total operating expenses	21,627	20,069	66,755	58,923
Income (loss) from operations	1,172	628	3,676	3,087
Gain on sale of KAH Hospice	(240)	0	(240)	0
Interest expense	102	88	293	235
Other expense (income), net	13	(1,096)	(16)	(562)
Income (loss) before income taxes and equity in net earnings	1,297	1,636	3,639	3,414
Equity in net earnings	3	15	1	69
Segment earnings (loss)	1,300	1,651	3,640	3,483
Net loss (income) attributable to noncontrolling interests	2		1
Segment earnings (loss) attributable to Humana	1,302		3,641
Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	16,007
Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,792
Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	534
Total Medicare
Segment Reporting Information [Line Items]
Premiums	18,333
Fully-insured
Segment Reporting Information [Line Items]
Premiums	1,100
Specialty
Segment Reporting Information [Line Items]
Premiums	425
Medicaid and other
Segment Reporting Information [Line Items]
Premiums	1,610
Home solutions
Segment Reporting Information [Line Items]
Services revenue:	519
Provider services
Segment Reporting Information [Line Items]
Services revenue:	159
ASO and other
Segment Reporting Information [Line Items]
Services revenue:	207
Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	274
Retail
Segment Reporting Information [Line Items]
Total revenues	20,189	18,440	62,486	55,633
Investment income (loss)	48	38	133	155
Total operating expenses	19,460	17,984	60,052	53,547
Group and Specialty
Segment Reporting Information [Line Items]
Total revenues	1,551	1,695	4,748	5,150
Investment income (loss)	3	3	10	11
Total operating expenses	1,502	1,723	4,466	4,964
Healthcare Services
Segment Reporting Information [Line Items]
Total revenues	8,880	8,038	26,530	22,760
Investment income (loss)	3	1	6	3
Total operating expenses	8,485	7,680	25,242	21,876
Operating segments
Segment Reporting Information [Line Items]
Premiums		19,885	66,437	59,987
Services revenue:		845	3,772	1,802
Total revenues	22,627	20,730	70,209	61,789
Operating segments | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums		14,642	49,751	44,042
Operating segments | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums		1,737	5,524	5,267
Operating segments | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums		541	1,779	1,867
Operating segments | Total Medicare
Segment Reporting Information [Line Items]
Premiums		16,920	57,054	51,176
Operating segments | Fully-insured
Segment Reporting Information [Line Items]
Premiums		1,237	3,382	3,774
Operating segments | Specialty
Segment Reporting Information [Line Items]
Premiums		432	1,281	1,298
Operating segments | Medicaid and other
Segment Reporting Information [Line Items]
Premiums		1,296	4,720	3,739
Operating segments | Home solutions
Segment Reporting Information [Line Items]
Services revenue:		374	1,997	423
Operating segments | Provider services
Segment Reporting Information [Line Items]
Services revenue:		110	409	298
Operating segments | ASO and other
Segment Reporting Information [Line Items]
Services revenue:		198	612	599
Operating segments | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:		163	754	482
Operating segments | Retail
Segment Reporting Information [Line Items]
Premiums	20,131	18,401	62,329	55,460
Services revenue:	10	0	24	17
Total revenues	20,141	18,401	62,353	55,477
Benefits	17,420	16,207	54,352	48,574
Operating costs	1,903	1,669	5,309	4,653
Depreciation and amortization	137	108	391	320
Income (loss) from operations	729	456	2,434	2,086
Gain on sale of KAH 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 earnings	729	456	2,434	2,086
Equity in net earnings	8	0	16	0
Segment earnings (loss)	737	456	2,450	2,086
Net loss (income) attributable to noncontrolling interests	2		2
Segment earnings (loss) attributable to Humana	739		2,452
Operating segments | Retail | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	16,007	14,642	49,751	44,042
Operating segments | Retail | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,792	1,737	5,524	5,267
Operating segments | Retail | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	534	541	1,779	1,867
Operating segments | Retail | Total Medicare
Segment Reporting Information [Line Items]
Premiums	18,333	16,920	57,054	51,176
Operating segments | Retail | Fully-insured
Segment Reporting Information [Line Items]
Premiums	188	185	555	545
Operating segments | Retail | Specialty
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Retail | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	1,610	1,296	4,720	3,739
Operating segments | Retail | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Retail | Provider services
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Retail | ASO and other
Segment Reporting Information [Line Items]
Services revenue:	10	0	24	17
Operating segments | Retail | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Group and Specialty
Segment Reporting Information [Line Items]
Premiums	1,337	1,484	4,108	4,527
Services revenue:	197	198	588	582
Total revenues	1,534	1,682	4,696	5,109
Benefits	1,052	1,282	3,143	3,674
Operating costs	427	421	1,255	1,227
Depreciation and amortization	23	20	68	63
Income (loss) from operations	49	(28)	282	186
Gain on sale of KAH 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 earnings	49	(28)	282	186
Equity in net earnings	0	0	0	0
Segment earnings (loss)	49	(28)	282	186
Net loss (income) attributable to noncontrolling interests	0		0
Segment earnings (loss) attributable to Humana	49		282
Operating segments | Group and Specialty | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Group and Specialty | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Group and Specialty | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Group and Specialty | Total Medicare
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Group and Specialty | Fully-insured
Segment Reporting Information [Line Items]
Premiums	912	1,052	2,827	3,229
Operating segments | Group and Specialty | Specialty
Segment Reporting Information [Line Items]
Premiums	425	432	1,281	1,298
Operating segments | Group and Specialty | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Group and Specialty | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Group and Specialty | Provider services
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Group and Specialty | ASO and other
Segment Reporting Information [Line Items]
Services revenue:	197	198	588	582
Operating segments | Group and Specialty | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Healthcare Services
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Services revenue:	952	647	3,160	1,203
Total revenues	952	647	3,160	1,203
Benefits	0	0	0	0
Operating costs	8,435	7,634	25,089	21,749
Depreciation and amortization	50	46	153	127
Income (loss) from operations	395	358	1,288	884
Gain on sale of KAH Hospice	(240)		(240)
Interest expense	0	0	0	0
Other expense (income), net	0	0	0	0
Income (loss) before income taxes and equity in net earnings	635	358	1,528	884
Equity in net earnings	(5)	15	(15)	69
Segment earnings (loss)	630	373	1,513	953
Net loss (income) attributable to noncontrolling interests	0		(1)
Segment earnings (loss) attributable to Humana	630		1,512
Operating segments | Healthcare Services | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Total Medicare
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Fully-insured
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Specialty
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	0	0	0	0
Operating segments | Healthcare Services | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	519	374	1,997	423
Operating segments | Healthcare Services | Provider services
Segment Reporting Information [Line Items]
Services revenue:	159	110	409	298
Operating segments | Healthcare Services | ASO and other
Segment Reporting Information [Line Items]
Services revenue:	0	0	0	0
Operating segments | Healthcare Services | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	274	163	754	482
Eliminations/ Corporate
Segment Reporting Information [Line Items]
Total revenues	(7,821)	(7,476)	(23,333)	(21,533)
Investment income (loss)	118	(75)	73	52
Benefits	(88)	(173)	(387)	(487)
Operating costs	(7,704)	(7,121)	(22,533)	(20,903)
Depreciation and amortization	(28)	(24)	(85)	(74)
Total operating expenses	(7,820)	(7,318)	(23,005)	(21,464)
Income (loss) from operations	(1)	(158)	(328)	(69)
Gain on sale of KAH Hospice	0		0
Interest expense	102	88	293	235
Other expense (income), net	13	(1,096)	(16)	(562)
Income (loss) before income taxes and equity in net earnings	(116)	850	(605)	258
Equity in net earnings	0	0	0	0
Segment earnings (loss)	(116)	850	(605)	258
Net loss (income) attributable to noncontrolling interests	0		0
Segment earnings (loss) attributable to Humana	(116)		(605)
Eliminations/ Corporate | Retail
Segment Reporting Information [Line Items]
Total revenues	0	1	0	1
Eliminations/ Corporate | Retail | Services
Segment Reporting Information [Line Items]
Total revenues	0	1	0	1
Eliminations/ Corporate | Retail | Products
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Eliminations/ Corporate | Group and Specialty
Segment Reporting Information [Line Items]
Total revenues	14	10	42	30
Eliminations/ Corporate | Group and Specialty | Services
Segment Reporting Information [Line Items]
Total revenues	14	10	42	30
Eliminations/ Corporate | Group and Specialty | Products
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Eliminations/ Corporate | Healthcare Services
Segment Reporting Information [Line Items]
Total revenues	7,925	7,390	23,364	21,554
Eliminations/ Corporate | Healthcare Services | Services
Segment Reporting Information [Line Items]
Total revenues	5,466	5,087	15,970	14,838
Eliminations/ Corporate | Healthcare Services | Products
Segment Reporting Information [Line Items]
Total revenues	2,459	2,303	7,394	6,716
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues	(7,939)	(7,401)	(23,406)	(21,585)
Intersegment Eliminations | Services
Segment Reporting Information [Line Items]
Total revenues	(5,480)	(5,098)	(16,012)	(14,869)
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Total revenues	$ (2,459)	$ (2,303)	$ (7,394)	$ (6,716)