SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Premiums	$ 25,550	$ 22,703
Services revenue:	999	1,264
Total revenues	26,742	23,970
Investment income (loss)	193	3
Benefits	21,858	19,625
Operating costs	2,979	2,886
Depreciation and amortization	186	170
Total operating expenses	25,023	22,681
Income from operations	1,719	1,289
Interest expense	113	90
Other income, net	(8)	(21)
Income before income taxes and equity in net losses	1,614	1,220
Equity in net losses	(17)	(4)
Segment earnings (loss)	1,597	1,216
Net loss (income) attributable to noncontrolling interests	1	0
Segment earnings (loss) attributable to Humana	1,598	1,216
Insurance
Segment Reporting Information [Line Items]
Total revenues	25,903	22,967
Investment income (loss)	97	46
Total operating expenses	24,576	21,971
CenterWell
Segment Reporting Information [Line Items]
Total revenues	4,505	4,365
Investment income (loss)	0	2
Total operating expenses	4,175	3,995
Operating segments
Segment Reporting Information [Line Items]
Premiums	25,550	22,703
Services revenue:	999	1,264
Total revenues	26,549	23,967
Operating segments | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,809	17,052
Operating segments | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,765	1,875
Operating segments | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	616	639
Operating segments | Total Medicare
Segment Reporting Information [Line Items]
Premiums	22,190	19,566
Operating segments | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	1,018	1,140
Operating segments | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	254	261
Operating segments | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	179	182
Operating segments | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	1,909	1,554
Operating segments | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	314	726
Operating segments | Provider services
Segment Reporting Information [Line Items]
Services revenue:	201	113
Operating segments | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue:	71	77
Operating segments | Military and other
Segment Reporting Information [Line Items]
Services revenue:	171	127
Operating segments | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	242	221
Operating segments | Insurance
Segment Reporting Information [Line Items]
Premiums	25,550	22,703
Services revenue:	242	204
Total revenues	25,792	22,907
Benefits	21,993	19,734
Operating costs	2,418	2,087
Depreciation and amortization	165	150
Income from operations	1,327	996
Interest expense	0	0
Other income, net	0	0
Income before income taxes and equity in net losses	1,327	996
Equity in net losses	(3)	0
Segment earnings (loss)	1,324	996
Net loss (income) attributable to noncontrolling interests	1	0
Segment earnings (loss) attributable to Humana	1,325	996
Operating segments | Insurance | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	19,809	17,052
Operating segments | Insurance | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	1,765	1,875
Operating segments | Insurance | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	616	639
Operating segments | Insurance | Total Medicare
Segment Reporting Information [Line Items]
Premiums	22,190	19,566
Operating segments | Insurance | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	1,018	1,140
Operating segments | Insurance | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	254	261
Operating segments | Insurance | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	179	182
Operating segments | Insurance | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	1,909	1,554
Operating segments | Insurance | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0
Operating segments | Insurance | Provider services
Segment Reporting Information [Line Items]
Services revenue:	0	0
Operating segments | Insurance | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue:	71	77
Operating segments | Insurance | Military and other
Segment Reporting Information [Line Items]
Services revenue:	171	127
Operating segments | Insurance | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	0	0
Operating segments | CenterWell
Segment Reporting Information [Line Items]
Premiums	0	0
Services revenue:	757	1,060
Total revenues	757	1,060
Benefits	0	0
Operating costs	4,126	3,948
Depreciation and amortization	49	47
Income from operations	330	370
Interest expense	0	0
Other income, net	0	0
Income before income taxes and equity in net losses	330	370
Equity in net losses	(14)	(4)
Segment earnings (loss)	316	366
Net loss (income) attributable to noncontrolling interests	0	0
Segment earnings (loss) attributable to Humana	316	366
Operating segments | CenterWell | Individual Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Group Medicare Advantage
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Medicare stand-alone PDP
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Total Medicare
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Commercial fully-insured
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Specialty benefits
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Medicare Supplement
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Medicaid and other
Segment Reporting Information [Line Items]
Premiums	0	0
Operating segments | CenterWell | Home solutions
Segment Reporting Information [Line Items]
Services revenue:	314	726
Operating segments | CenterWell | Provider services
Segment Reporting Information [Line Items]
Services revenue:	201	113
Operating segments | CenterWell | Commercial ASO
Segment Reporting Information [Line Items]
Services revenue:	0	0
Operating segments | CenterWell | Military and other
Segment Reporting Information [Line Items]
Services revenue:	0	0
Operating segments | CenterWell | Pharmacy solutions
Segment Reporting Information [Line Items]
Services revenue:	242	221
Eliminations/ Corporate
Segment Reporting Information [Line Items]
Total revenues	(3,666)	(3,362)
Investment income (loss)	96	(45)
Benefits	(135)	(109)
Operating costs	(3,565)	(3,149)
Depreciation and amortization	(28)	(27)
Total operating expenses	(3,728)	(3,285)
Income from operations	62	(77)
Interest expense	113	90
Other income, net	(8)	(21)
Income before income taxes and equity in net losses	(43)	(146)
Equity in net losses	0	0
Segment earnings (loss)	(43)	(146)
Net loss (income) attributable to noncontrolling interests	0	0
Segment earnings (loss) attributable to Humana	(43)	(146)
Eliminations/ Corporate | Insurance
Segment Reporting Information [Line Items]
Total revenues	14	14
Eliminations/ Corporate | Insurance | Services
Segment Reporting Information [Line Items]
Total revenues	14	14
Eliminations/ Corporate | Insurance | Products
Segment Reporting Information [Line Items]
Total revenues	0	0
Eliminations/ Corporate | CenterWell
Segment Reporting Information [Line Items]
Total revenues	3,748	3,303
Eliminations/ Corporate | CenterWell | Services
Segment Reporting Information [Line Items]
Total revenues	1,133	857
Eliminations/ Corporate | CenterWell | Products
Segment Reporting Information [Line Items]
Total revenues	2,615	2,446
Intersegment Eliminations
Segment Reporting Information [Line Items]
Total revenues	(3,762)	(3,317)
Intersegment Eliminations | Services
Segment Reporting Information [Line Items]
Total revenues	(1,147)	(871)
Intersegment Eliminations | Products
Segment Reporting Information [Line Items]
Total revenues	$ (2,615)	$ (2,446)