FAIR VALUE MEASUREMENTS (Details - Assets and Liabilities Measured at Fair Value on a Recurring Basis) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Sep. 30, 2017
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		$ 233,914		$ 238,992
Other bond securities		12,397		12,772
Equity securities available for sale		0		1,708
Other equity securities		1,725		589
Other invested assets		6,232		6,248
Derivative Assets, Fair Value		3,631		3,545
Derivative assets, Counterparty netting		(1,589)		(1,464)
Derivative assets, Cash collateral		(1,268)		(1,159)
Short-term investments, portion measured at fair value		3,094		2,615
Separate account assets, at fair value		90,589		92,798
Other assets		774		922
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		3,711		4,150
Other policyholder funds		3,473		3,648
Derivative Liabilities, Fair Value		3,702		3,748
Derivative liabilities, Counterparty netting		(1,589)		(1,464)
Derivative liabilities, Cash collateral		(980)		(1,249)
Long-term debt, portion measured at fair value		2,820		2,888
Other liabilities		1,158		1,124
Fair Value Option
Fair Value, Liabilities Measured on Recurring Basis
Long-term debt, portion measured at fair value		2,820		2,888
U.S. government and government sponsored entities
Fair Value, Liabilities Measured on Recurring Basis
Assets transferred from Level 1 to Level 2		191	$ 63
Non-U.S. governments
Fair Value, Liabilities Measured on Recurring Basis
Assets transferred from Level 1 to Level 2		16	$ 53
Preferred Stock
Fair Value, Liabilities Measured on Recurring Basis
Assets transferred from Level 1 to Level 2	$ 0	0
Recurring Basis
Fair Value, Liabilities Measured on Recurring Basis
Assets transferred from Level 2 to Level 1		0			$ 0
Recurring Basis | Fair Value Option
Fair Value, Assets Measured on Recurring Basis
Other invested assets		5,900		6,000
Recurring Basis | Level 1
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		25		221
Other bond securities		594		238
Equity securities available for sale		0		1,189
Other equity securities		1,716		589
Other invested assets		5		0
Derivative Assets, Fair Value		48		189
Short-term investments, portion measured at fair value		2,611		2,078
Separate account assets, at fair value		85,362		87,141
Fair value assets measured on recurring basis, total		90,361		91,645
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		0		0
Derivative Liabilities, Fair Value		1		4
Long-term debt, portion measured at fair value		0		0
Other liabilities		25		46
Fair value liabilities measured on recurring basis, total		26		50
Recurring Basis | Level 1 | Interest rate contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		1
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		1		2
Recurring Basis | Level 1 | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		0
Recurring Basis | Level 1 | Equity contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		48		188
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		2
Recurring Basis | Level 1 | Credit contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		0
Recurring Basis | Level 1 | Other contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		0
Recurring Basis | Level 1 | U.S. government and government sponsored entities
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		201
Other bond securities		594		238
Recurring Basis | Level 1 | Obligations of states, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Recurring Basis | Level 1 | Non-U.S. governments
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		25		20
Other bond securities		0		0
Recurring Basis | Level 1 | Corporate debt
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Other bond securities		0		0
Recurring Basis | Level 1 | Residential mortgage-backed securities (RMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Other bond securities		0		0
Recurring Basis | Level 1 | Commercial mortgage-backed securities (CMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Other bond securities		0		0
Recurring Basis | Level 1 | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Other bond securities		0		0
Recurring Basis | Level 1 | Common Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		1,061
Recurring Basis | Level 1 | Preferred Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		18
Recurring Basis | Level 1 | Mutual Funds
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		110
Recurring Basis | Level 2
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		205,479		209,775
Other bond securities		5,508		6,022
Equity securities available for sale		0		519
Other equity securities		6		0
Other invested assets		1		1
Derivative Assets, Fair Value		3,483		3,249
Short-term investments, portion measured at fair value		483		537
Separate account assets, at fair value		5,227		5,657
Fair value assets measured on recurring basis, total		220,187		225,760
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		15		14
Derivative Liabilities, Fair Value		3,423		3,450
Long-term debt, portion measured at fair value		2,820		2,888
Other liabilities		0		43
Fair value liabilities measured on recurring basis, total		6,258		6,395
Recurring Basis | Level 2 | Interest rate contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		2,549		2,170
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		2,185		2,176
Recurring Basis | Level 2 | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		792		827
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		1,213		1,241
Recurring Basis | Level 2 | Equity contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		142		252
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		13		19
Recurring Basis | Level 2 | Credit contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		12		14
Recurring Basis | Level 2 | Other contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		0
Recurring Basis | Level 2 | U.S. government and government sponsored entities
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		2,833		2,455
Other bond securities		2,183		2,564
Recurring Basis | Level 2 | Obligations of states, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		15,550		16,240
Recurring Basis | Level 2 | Non-U.S. governments
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		15,689		15,631
Other bond securities		54		57
Recurring Basis | Level 2 | Corporate debt
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		129,468		133,003
Other bond securities		1,784		1,891
Recurring Basis | Level 2 | Residential mortgage-backed securities (RMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		20,050		21,098
Other bond securities		391		421
Recurring Basis | Level 2 | Commercial mortgage-backed securities (CMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		13,025		13,217
Other bond securities		493		485
Recurring Basis | Level 2 | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		8,864		8,131
Other bond securities		603		604
Recurring Basis | Level 2 | Common Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		0
Recurring Basis | Level 2 | Preferred Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		515
Recurring Basis | Level 2 | Mutual Funds
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		4
Recurring Basis | Level 3
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		28,410		28,996
Other bond securities		6,295		6,512
Equity securities available for sale		0		0
Other equity securities		3		0
Mortgage and other loans receivable				5
Other invested assets		292		250
Derivative Assets, Fair Value		100		107
Short-term investments, portion measured at fair value		0		0
Separate account assets, at fair value		0
Fair value assets measured on recurring basis, total		35,100		35,870
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		3,696		4,136
Derivative Liabilities, Fair Value		278		294
Long-term debt, portion measured at fair value		0		0
Other liabilities		0		0
Fair value liabilities measured on recurring basis, total		3,974		4,430
Recurring Basis | Level 3 | Interest rate contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		0		0
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		17		22
Recurring Basis | Level 3 | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		3		4
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		4		4
Recurring Basis | Level 3 | Equity contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		78		82
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		0		0
Recurring Basis | Level 3 | Credit contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		2		1
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		252		263
Recurring Basis | Level 3 | Other contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		17		20
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		5		5
Recurring Basis | Level 3 | U.S. government and government sponsored entities
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		0		0
Other bond securities		0		0
Recurring Basis | Level 3 | Obligations of states, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		2,261		2,404
Recurring Basis | Level 3 | Non-U.S. governments
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		9		8
Other bond securities		0		0
Recurring Basis | Level 3 | Corporate debt
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		1,871		1,173
Other bond securities		19		18
Recurring Basis | Level 3 | Residential mortgage-backed securities (RMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		15,839		16,136
Other bond securities		1,427		1,464
Recurring Basis | Level 3 | Commercial mortgage-backed securities (CMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		584		624
Other bond securities		73		74
Recurring Basis | Level 3 | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		7,846		8,651
Other bond securities		4,776		4,956
Recurring Basis | Level 3 | Common Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		0
Recurring Basis | Level 3 | Preferred Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		0
Recurring Basis | Level 3 | Mutual Funds
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		0
Recurring Basis | Counterparty Netting
Fair Value, Assets Measured on Recurring Basis
Other bond securities		0
Equity securities available for sale		0
Other equity securities		0
Other invested assets		0
Derivative assets, Counterparty netting		(1,589)		(1,464)
Separate account assets, at fair value		0
Fair value assets measured on recurring basis, total		(1,589)		(1,464)
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		0
Derivative liabilities, Counterparty netting		(1,589)		(1,464)
Long-term debt, portion measured at fair value		0
Other liabilities		0
Fair value liabilities measured on recurring basis, total		(1,589)		(1,464)
Recurring Basis | Counterparty Netting | Counterparty netting and cash collateral
Fair Value, Assets Measured on Recurring Basis
Derivative assets, Counterparty netting		(1,589)		(1,464)
Fair Value, Liabilities Measured on Recurring Basis
Derivative liabilities, Counterparty netting		(1,589)		(1,464)
Recurring Basis | Cash Collateral
Fair Value, Assets Measured on Recurring Basis
Other bond securities		0
Equity securities available for sale		0
Other equity securities		0
Other invested assets		0
Derivative assets, Cash collateral		(1,268)		(1,159)
Separate account assets, at fair value		0
Fair value assets measured on recurring basis, total		(1,268)		(1,159)
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		0
Derivative liabilities, Cash collateral		(980)		(1,249)
Long-term debt, portion measured at fair value		0
Other liabilities		0
Fair value liabilities measured on recurring basis, total		(980)		(1,249)
Recurring Basis | Cash Collateral | Counterparty netting and cash collateral
Fair Value, Assets Measured on Recurring Basis
Derivative assets, Cash collateral		(1,268)		(1,159)
Fair Value, Liabilities Measured on Recurring Basis
Derivative liabilities, Cash collateral		(980)		(1,249)
Recurring Basis | Total Fair Value
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		233,914		238,992
Other bond securities		12,397		12,772
Equity securities available for sale		0		1,708
Other equity securities		1,725		589
Mortgage and other loans receivable				5
Other invested assets		298		251
Derivative Assets, Fair Value		774		922
Short-term investments, portion measured at fair value		3,094		2,615
Separate account assets, at fair value		90,589		92,798
Fair value assets measured on recurring basis, total		342,791		350,652
Fair Value, Liabilities Measured on Recurring Basis
Policyholder contract deposits, portion measured at fair value		3,711		4,150
Derivative Liabilities, Fair Value		1,133		1,035
Long-term debt, portion measured at fair value		2,820		2,888
Other liabilities		25		89
Fair value liabilities measured on recurring basis, total		7,689		8,162
Recurring Basis | Total Fair Value | Interest rate contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		2,549		2,171
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		2,203		2,200
Recurring Basis | Total Fair Value | Foreign exchange contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		795		831
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		1,217		1,245
Recurring Basis | Total Fair Value | Equity contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		268		522
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		13		21
Recurring Basis | Total Fair Value | Credit contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		2		1
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		264		277
Recurring Basis | Total Fair Value | Other contracts
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		17		20
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		5		5
Recurring Basis | Total Fair Value | Counterparty netting and cash collateral
Fair Value, Assets Measured on Recurring Basis
Derivative Assets, Fair Value		(2,857)		(2,623)
Fair Value, Liabilities Measured on Recurring Basis
Derivative Liabilities, Fair Value		(2,569)		(2,713)
Recurring Basis | Total Fair Value | U.S. government and government sponsored entities
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		2,833		2,656
Other bond securities		2,777		2,802
Recurring Basis | Total Fair Value | Obligations of states, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		17,811		18,644
Recurring Basis | Total Fair Value | Non-U.S. governments
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		15,723		15,659
Other bond securities		54		57
Recurring Basis | Total Fair Value | Corporate debt
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		131,339		134,176
Other bond securities		1,803		1,909
Recurring Basis | Total Fair Value | Residential mortgage-backed securities (RMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		35,889		37,234
Other bond securities		1,818		1,885
Recurring Basis | Total Fair Value | Commercial mortgage-backed securities (CMBS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		13,609		13,841
Other bond securities		566		559
Recurring Basis | Total Fair Value | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair Value, Assets Measured on Recurring Basis
Bonds available for sale		16,710		16,782
Other bond securities		5,379		5,560
Recurring Basis | Total Fair Value | Common Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		1,061
Recurring Basis | Total Fair Value | Preferred Stock
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		0		533
Recurring Basis | Total Fair Value | Mutual Funds
Fair Value, Assets Measured on Recurring Basis
Equity securities available for sale		$ 0		$ 114