INVESTMENTS - Details of Holdings of Perpetual Securities (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Investment Holdings [Line Items]
Amortized Cost	$ 58,661	$ 57,646
Fair Value	58,666	61,578
Unrealized Gain (Loss)	5	3,932
Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	3,266	4,213
Fair Value	2,834	4,302
Unrealized Gain (Loss)	(432)	89
Upper Tier II | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	2,084	2,825
Fair Value	1,877	2,919
Unrealized Gain (Loss)	(207)	94
Upper Tier II | A | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	160	460
Fair Value	180	488
Unrealized Gain (Loss)	20	28
Upper Tier II | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	1,671	2,077
Fair Value	1,503	2,129
Unrealized Gain (Loss)	(168)	52
Upper Tier II | BB or Lower | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	253	288
Fair Value	194	302
Unrealized Gain (Loss)	(59)	14
Tier I | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	910	1,079
Fair Value	754	1,031
Unrealized Gain (Loss)	(156)	(48)
Tier I | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	798	966
Fair Value	640	904
Unrealized Gain (Loss)	(158)	(62)
Other subordinated - non-banks | BBB Credit Rating | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	272	309
Fair Value	203	352
Unrealized Gain (Loss)	(69)	43
Other subordinated - non-banks | BB or Lower | Perpetual Securities
Investment Holdings [Line Items]
Amortized Cost	112	113
Fair Value	114	127
Unrealized Gain (Loss)	$ 2	$ 14