Schedule III - Supplementary Insurance Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	$ 1,395		$ 1,198		$ 817
Future policy benefits and contractholder deposit funds	17,776		17,773		17,146
Medical claims payable and unpaid claims	6,348		5,918		5,241
Unearned premiums and fees	580		549		502
Premiums and fees	28,976	[1]	26,187	[1]	18,966	[1]
Net investment income	1,164	[2]	1,144	[2]	1,146	[2]
Benefit expenses	20,865	[1],[3]	17,900	[1],[3]	12,490	[1],[3]
Amortization of deferred policy acquisition expenses	255		218		259
Other operating expenses	9,084	[4]	8,524	[4]	7,240	[4]
Global Health Care [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	20		19		19
Future policy benefits and contractholder deposit funds	197		175		170
Medical claims payable and unpaid claims	2,050		1,856		1,443
Unearned premiums and fees	116		111		103
Premiums and fees	22,933	[1]	20,973	[1]	14,443	[1]
Net investment income	325	[2]	259	[2]	263	[2]
Benefit expenses	15,867	[1],[3]	14,228	[1],[3]	9,125	[1],[3]
Amortization of deferred policy acquisition expenses	69		68		139
Other operating expenses	7,021	[4]	6,573	[4]	5,404	[4]
Global Supplemental Benefits [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	1,323		1,113		729
Future policy benefits and contractholder deposit funds	2,525		2,227		1,255
Medical claims payable and unpaid claims	305		306		177
Unearned premiums and fees	419		388		346
Premiums and fees	2,513	[1]	1,984	[1]	1,528	[1]
Net investment income	100	[2]	90	[2]	83	[2]
Benefit expenses	1,310	[1],[3]	1,005	[1],[3]	754	[1],[3]
Amortization of deferred policy acquisition expenses	178		141		110
Other operating expenses	924	[4]	770	[4]	628	[4]
Group Disability And Life [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	1		1		1
Future policy benefits and contractholder deposit funds	1,615		1,599		1,572
Medical claims payable and unpaid claims	3,739		3,482		3,228
Unearned premiums and fees	23		26		26
Premiums and fees	3,425	[1]	3,109	[1]	2,857	[1]
Net investment income	321	[2]	300	[2]	291	[2]
Benefit expenses	2,621	[1],[3]	2,290	[1],[3]	2,086	[1],[3]
Amortization of deferred policy acquisition expenses	1		3		4
Other operating expenses	765	[4]	721	[4]	650	[4]
Run-off Reinsurance [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	0		0		0
Future policy benefits and contractholder deposit funds	1,400		1,094		1,172
Medical claims payable and unpaid claims	126		153		240
Unearned premiums and fees	0		0		0
Premiums and fees	1	[1]	21	[1]	24	[1]
Net investment income	19	[2]	102	[2]	103	[2]
Benefit expenses	700	[1],[3]	16	[1],[3]	140	[1],[3]
Amortization of deferred policy acquisition expenses	0		0		0
Other operating expenses	31	[4]	(12)	[4]	265	[4]
Other Operations [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	51		65		68
Future policy benefits and contractholder deposit funds	12,039		12,678		12,977
Medical claims payable and unpaid claims	134		142		160
Unearned premiums and fees	22		24		27
Premiums and fees	104	[1]	100	[1]	114	[1]
Net investment income	389	[2]	388	[2]	400	[2]
Benefit expenses	367	[1],[3]	361	[1],[3]	385	[1],[3]
Amortization of deferred policy acquisition expenses	7		6		6
Other operating expenses	48	[4]	51	[4]	60	[4]
Corporate [Member]
Supplementary Insurance Information, by Segment [Line Items]
Deferred policy acquisition costs	0		0		0
Future policy benefits and contractholder deposit funds	0		0		0
Medical claims payable and unpaid claims	(6)		(21)		(7)
Unearned premiums and fees	0		0		0
Premiums and fees	0	[1]	0	[1]	0	[1]
Net investment income	10	[2]	5	[2]	6	[2]
Benefit expenses	0	[1],[3]	0	[1],[3]	0	[1],[3]
Amortization of deferred policy acquisition expenses	0		0		0
Other operating expenses	$ 295	[4]	$ 421	[4]	$ 233	[4]

[1] Amounts presented are shown net of the effects of reinsurance. See Note 7 to the Consolidated Financial Statements included in this Form 10-K.

[2] The allocation of net investment income is based upon the investment year method, the identification of certain portfolios with specific segments, or a combination of both.

[3] Benefit expenses include Global Health Care medical claims expense and other benefit expenses.

[4] Other operating expenses include mail order pharmacy cost of goods sold, GMIB fair value (gain) loss and other operating expenses, and excludes amortization of deferred policy acquisition expenses.