SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Liability For Future Policy Benefit, Expected Net Premium, Activity (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2023	Dec. 31, 2022	Dec. 31, 2021		Dec. 31, 2020
Cancer | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		$ 19,298	$ 25,893
Beginning balance at original discount rate		18,221	22,470
Effect of changes in cash flow assumptions			0	$ (639)
Effect of actual variances from expected experience			(198)	(284)
Adjusted beginning of period balance			18,023	21,547
Issuances		498	947
Interest accrual		218	459
Net premium earned	[1]	(824)	(1,734)
Foreign currency translation		(1,521)	(2,997)
Other		0	(1)
Ending balance at original discount rate		16,394	18,221	22,470
Effect of changes in discount rate assumptions		1,579	1,077
Ending balance		17,973	19,298	25,893
Cancer | Aflac Japan | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			25,893	29,598
Beginning balance at original discount rate			22,470	25,616	[2]
Effect of changes in cash flow assumptions						$ 32
Effect of actual variances from expected experience						(134)
Adjusted beginning of period balance						25,514
Issuances				1,116
Interest accrual				586
Net premium earned	[3]			(2,206)
Foreign currency translation				(2,539)
Other				(1)
Ending balance at original discount rate				22,470
Effect of changes in discount rate assumptions				3,423
Ending balance				25,893
Medical and other health | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		16,714	21,174
Beginning balance at original discount rate		16,195	18,681
Effect of changes in cash flow assumptions			0	317
Effect of actual variances from expected experience			(61)	61
Adjusted beginning of period balance			16,134	19,059
Issuances		204	639
Interest accrual		180	364
Net premium earned	[1]	(673)	(1,376)
Foreign currency translation		(1,348)	(2,488)
Other		0	(3)
Ending balance at original discount rate		14,497	16,195	18,681
Effect of changes in discount rate assumptions		1,135	519
Ending balance		15,632	16,714	21,174
Medical and other health | Aflac Japan | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			21,174	23,874
Beginning balance at original discount rate			18,681	21,276	[2]
Effect of changes in cash flow assumptions						88
Effect of actual variances from expected experience						(449)
Adjusted beginning of period balance						20,915
Issuances				1,132
Interest accrual				439
Net premium earned	[3]			(1,692)
Foreign currency translation				(2,111)
Other				(2)
Ending balance at original discount rate				18,681
Effect of changes in discount rate assumptions				2,493
Ending balance				21,174
Life insurance | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		7,485	10,847
Beginning balance at original discount rate		7,284	10,064
Effect of changes in cash flow assumptions			0	(494)
Effect of actual variances from expected experience			(22)	(81)
Adjusted beginning of period balance			7,262	9,489
Issuances		198	221
Interest accrual		66	146
Net premium earned	[1]	(549)	(1,229)
Foreign currency translation		(597)	(1,343)
Other		0	0
Ending balance at original discount rate		6,380	7,284	10,064
Effect of changes in discount rate assumptions		335	201
Ending balance		6,715	7,485	10,847
Life insurance | Aflac Japan | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			10,847	13,384
Beginning balance at original discount rate			10,064	12,476	[2]
Effect of changes in cash flow assumptions						40
Effect of actual variances from expected experience						(135)
Adjusted beginning of period balance						12,381
Issuances				284
Interest accrual				202
Net premium earned	[3]			(1,609)
Foreign currency translation				(1,194)
Other				0
Ending balance at original discount rate				10,064
Effect of changes in discount rate assumptions				783
Ending balance				10,847
Life insurance | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		724	834
Beginning balance at original discount rate		799	780
Effect of changes in cash flow assumptions			0	(1)
Effect of actual variances from expected experience			(9)	(16)
Adjusted beginning of period balance			790	763
Issuances		90	146
Interest accrual		14	27
Net premium earned	[1]	(65)	(131)
Foreign currency translation		0	0
Other		2	(6)
Ending balance at original discount rate		831	799	780
Effect of changes in discount rate assumptions		(68)	(75)
Ending balance		763	724	834
Life insurance | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			834	783
Beginning balance at original discount rate			780	705	[2]
Effect of changes in cash flow assumptions						31
Effect of actual variances from expected experience						34
Adjusted beginning of period balance						770
Issuances				112
Interest accrual				25
Net premium earned	[3]			(124)
Foreign currency translation				0
Other				(3)
Ending balance at original discount rate				780
Effect of changes in discount rate assumptions				54
Ending balance				834
Accident | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		2,534	3,283
Beginning balance at original discount rate		2,760	2,999
Effect of changes in cash flow assumptions			0	(52)
Effect of actual variances from expected experience			(51)	(152)
Adjusted beginning of period balance			2,709	2,795
Issuances		185	355
Interest accrual		51	105
Net premium earned	[1]	(237)	(496)
Foreign currency translation		0	0
Other		(3)	1
Ending balance at original discount rate		2,705	2,760	2,999
Effect of changes in discount rate assumptions		(201)	(226)
Ending balance		2,504	2,534	3,283
Accident | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			3,283	3,829
Beginning balance at original discount rate			2,999	3,350	[2]
Effect of changes in cash flow assumptions						(163)
Effect of actual variances from expected experience						(109)
Adjusted beginning of period balance						3,078
Issuances				365
Interest accrual				116
Net premium earned	[3]			(552)
Foreign currency translation				0
Other				(8)
Ending balance at original discount rate				2,999
Effect of changes in discount rate assumptions				284
Ending balance				3,283
Disability | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		1,635	1,862
Beginning balance at original discount rate		1,775	1,760
Effect of changes in cash flow assumptions			0	5
Effect of actual variances from expected experience			(15)	(43)
Adjusted beginning of period balance			1,760	1,722
Issuances		204	384
Interest accrual		30	57
Net premium earned	[1]	(193)	(382)
Foreign currency translation		0	0
Other		(3)	(6)
Ending balance at original discount rate		1,798	1,775	1,760
Effect of changes in discount rate assumptions		(129)	(140)
Ending balance		1,669	1,635	1,862
Disability | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			1,862	2,118
Beginning balance at original discount rate			1,760	1,921	[2]
Effect of changes in cash flow assumptions						(129)
Effect of actual variances from expected experience						(38)
Adjusted beginning of period balance						1,754
Issuances				345
Interest accrual				61
Net premium earned	[3]			(393)
Foreign currency translation				0
Other				(7)
Ending balance at original discount rate				1,760
Effect of changes in discount rate assumptions				102
Ending balance				1,862
Critical Care | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		4,486	6,023
Beginning balance at original discount rate		5,050	5,391
Effect of changes in cash flow assumptions			0	(38)
Effect of actual variances from expected experience			(139)	(421)
Adjusted beginning of period balance			4,911	4,932
Issuances		291	537
Interest accrual		94	193
Net premium earned	[1]	(298)	(612)
Foreign currency translation		0	0
Other		(2)	0
Ending balance at original discount rate		4,996	5,050	5,391
Effect of changes in discount rate assumptions		(497)	(564)
Ending balance		4,499	4,486	6,023
Critical Care | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			6,023	6,942
Beginning balance at original discount rate			5,391	5,894	[2]
Effect of changes in cash flow assumptions						(302)
Effect of actual variances from expected experience						(290)
Adjusted beginning of period balance						5,302
Issuances				552
Interest accrual				210
Net premium earned	[3]			(665)
Foreign currency translation				0
Other				(8)
Ending balance at original discount rate				5,391
Effect of changes in discount rate assumptions				632
Ending balance				6,023
Hospital Indemnity | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		1,220	1,467
Beginning balance at original discount rate		1,365	1,380
Effect of changes in cash flow assumptions			0	42
Effect of actual variances from expected experience			(44)	(111)
Adjusted beginning of period balance			1,321	1,311
Issuances		153	273
Interest accrual		23	45
Net premium earned	[1]	(127)	(261)
Foreign currency translation		0	0
Other		(1)	(3)
Ending balance at original discount rate		1,369	1,365	1,380
Effect of changes in discount rate assumptions		(129)	(145)
Ending balance		1,240	1,220	1,467
Hospital Indemnity | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			1,467	1,530
Beginning balance at original discount rate			1,380	1,376	[2]
Effect of changes in cash flow assumptions						0
Effect of actual variances from expected experience						(32)
Adjusted beginning of period balance						1,344
Issuances				263
Interest accrual				45
Net premium earned	[3]			(268)
Foreign currency translation				0
Other				(4)
Ending balance at original discount rate				1,380
Effect of changes in discount rate assumptions				87
Ending balance				1,467
Dental/Vision | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		211	264
Beginning balance at original discount rate		231	241
Effect of changes in cash flow assumptions			0	10
Effect of actual variances from expected experience			(11)	(20)
Adjusted beginning of period balance			220	231
Issuances		20	33
Interest accrual		4	9
Net premium earned	[1]	(20)	(42)
Foreign currency translation		0	0
Other		2	0
Ending balance at original discount rate		226	231	241
Effect of changes in discount rate assumptions		(17)	(20)
Ending balance		209	211	264
Dental/Vision | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			264	322
Beginning balance at original discount rate			241	281	[2]
Effect of changes in cash flow assumptions						(26)
Effect of actual variances from expected experience						(14)
Adjusted beginning of period balance						241
Issuances				39
Interest accrual				10
Net premium earned	[3]			(47)
Foreign currency translation				0
Other				(2)
Ending balance at original discount rate				241
Effect of changes in discount rate assumptions				23
Ending balance				264
Other | Aflac Japan
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		1,256	1,586
Beginning balance at original discount rate		1,242	1,461
Effect of changes in cash flow assumptions			0	25
Effect of actual variances from expected experience			(5)	(10)
Adjusted beginning of period balance			1,237	1,476
Issuances		14	62
Interest accrual		11	22
Net premium earned	[1]	(60)	(123)
Foreign currency translation		(104)	(195)
Other		0	0
Ending balance at original discount rate		1,098	1,242	1,461
Effect of changes in discount rate assumptions		47	14
Ending balance		1,145	1,256	1,586
Other | Aflac Japan | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			1,586	1,856
Beginning balance at original discount rate			1,461	1,708	[2]
Effect of changes in cash flow assumptions						1
Effect of actual variances from expected experience						(11)
Adjusted beginning of period balance						1,698
Issuances				55
Interest accrual				27
Net premium earned	[3]			(151)
Foreign currency translation				(167)
Other				(1)
Ending balance at original discount rate				1,461
Effect of changes in discount rate assumptions				125
Ending balance				1,586
Other | Aflac U.S.
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance		110	153
Beginning balance at original discount rate		118	135
Effect of changes in cash flow assumptions			0	(12)
Effect of actual variances from expected experience			0	6
Adjusted beginning of period balance			118	129
Issuances		55	0
Interest accrual		3	5
Net premium earned	[1]	(8)	(17)
Foreign currency translation		0	0
Other		9	1
Ending balance at original discount rate		177	118	135
Effect of changes in discount rate assumptions		(8)	(8)
Ending balance		$ 169	110	153
Other | Aflac U.S. | Accounting Standards Update 2018-12
Liability for Future Policy Benefit, Activity [Line Items]
Beginning balance			153	179
Beginning balance at original discount rate			$ 135	152	[2]
Effect of changes in cash flow assumptions						0
Effect of actual variances from expected experience						(3)
Adjusted beginning of period balance						$ 149
Issuances				0
Interest accrual				6
Net premium earned	[3]			(19)
Foreign currency translation				0
Other				(1)
Ending balance at original discount rate				135
Effect of changes in discount rate assumptions				18
Ending balance				$ 153

[1] Net premiums earned represent the portion of gross premiums collected from policyholders that is used to fund expected benefit payments.

[2] Includes the adjustment for capping the Transition Date NPR.

[3] Net premiums earned represent the portion of gross premiums collected from policyholders that is used to fund expected benefit payments.