INVESTMENTS - Details of Holdings of Perpetual Securities (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Investment Holdings [Line Items]
Amortized Cost	$ 59,722	$ 57,646
Fair Value	59,886	61,578
Unrealized Gain (Loss)	164	3,932
Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	3,293	4,213
Fair Value	2,941	4,302
Unrealized Gain (Loss)	(352)	89
Upper Tier II | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	2,102	2,825
Fair Value	1,941	2,919
Unrealized Gain (Loss)	(161)	94
Upper Tier II | A | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	161	460
Fair Value	179	488
Unrealized Gain (Loss)	18	28
Upper Tier II | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	1,686	2,077
Fair Value	1,559	2,129
Unrealized Gain (Loss)	(127)	52
Upper Tier II | BB or Lower | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	255	288
Fair Value	203	302
Unrealized Gain (Loss)	(52)	14
Tier I | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	917	1,079
Fair Value	791	1,031
Unrealized Gain (Loss)	(126)	(48)
Tier I | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	804	966
Fair Value	675	904
Unrealized Gain (Loss)	(129)	(62)
Other subordinated - non-banks | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	274	309
Fair Value	209	352
Unrealized Gain (Loss)	(65)	43
Other subordinated - non-banks | BB or Lower | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	113	113
Fair Value	116	127
Unrealized Gain (Loss)	$ 3	$ 14