INVESTMENTS - Held-to-Maturity Investments in Debt Securities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	$ 44,415	$ 54,426
Gross Unrealized Gains	2,041	1,213
Gross Unrealized Losses	610	798
Fair Value	45,846	54,841
Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	45,846	54,841
Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	44,415	54,426
Gross Unrealized Gains	2,041	1,213
Gross Unrealized Losses	610	798
Fair Value	45,846	54,841
Japan government and agencies | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	28,708	32,332
Japan government and agencies | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	27,362	32,043
Gross Unrealized Gains	1,347	356
Gross Unrealized Losses	1	67
Fair Value	28,708	32,332
Municipalities | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	440	520
Municipalities | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	399	492
Gross Unrealized Gains	41	30
Gross Unrealized Losses	0	2
Fair Value	440	520
Mortgage- and asset-backed Securities | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	61	94
Mortgage- and asset-backed Securities | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	58	90
Gross Unrealized Gains	3	4
Gross Unrealized Losses	0	0
Fair Value	61	94
Public Utilities | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	3,928	5,051
Public Utilities | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	3,900	4,924
Gross Unrealized Gains	150	233
Gross Unrealized Losses	122	106
Fair Value	3,928	5,051
Sovereign and Supranational | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	3,040	3,317
Sovereign and Supranational | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	2,941	3,209
Gross Unrealized Gains	171	192
Gross Unrealized Losses	72	84
Fair Value	3,040	3,317
Banks/financial Institutions | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	6,128	8,991
Banks/financial Institutions | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	6,310	9,211
Gross Unrealized Gains	146	211
Gross Unrealized Losses	328	431
Fair Value	6,128	8,991
Other Corporate | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Fair Value	3,541	4,536
Other Corporate | Yen Denominated | Fixed Maturities
Schedule of Held-to-maturity Securities [Line Items]
Cost or Amortized Cost	3,445	4,457
Gross Unrealized Gains	183	187
Gross Unrealized Losses	87	108
Fair Value	$ 3,541	$ 4,536