Consolidated Statements of Shareholders' Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended															12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement Of Comprehensive Income [Abstract]
Shareholders' Net Income	$ 361	[1]	$ 553	$ 505	[2]	$ 57	[3]	$ 406	[4]	$ 466	[5]	$ 380	[6]	$ 371	[7]	$ 1,476	$ 1,623	$ 1,260
Net unrealized appreciation (depreciation) on securities:
Fixed maturities																(410)	144	210
Equity securities																0	3	(2)
Net unrealized appreciation (depreciation) on securities																(410)	147	208
Net unrealized appreciation (depreciation), derivatives																9	(5)	1
Net translation of foreign currencies																13	66	(22)
Postretirement benefits liability adjustment																539	(92)	(360)
Shareholders' other comprehensive income																151	116	(173)
Shareholders' comprehensive income (loss)																$ 1,627	$ 1,739	$ 1,087

[1] The fourth quarter of 2013 includes an after-tax charge of $40 million for an organizational efficiency plan.

[2] The second quarter of 2013 includes an after-tax charge of $24 million for the Pharmacy Benefits Manager (“PBM”) partnering agreement with Catamaran.

[3] The first quarter of 2013 includes an after-tax gain of $25 for the GMIB business, an after-tax charge of $507 million for the transaction with Berkshire to effectively exit the Run-off Reinsurance business, and an after-tax charge of $51 million related to the disability claims regulatory matter in the Group Disability and Life segment.

[4] The fourth quarter of 2012 includes an after-tax gain of $7 million for the GMIB business and an after-tax charge of $68 million for litigation matters.

[5] The third quarter of 2012 includes an after-tax gain of $32 million for the GMIB business, an after-tax charge of $12 million for costs associated with acquisitions, and an after-tax charge of $50 million for costs associated with an organizational efficiency plan.

[6] The second quarter of 2012 includes an after-tax loss of $51 million for the GMIB business.

[7] The first quarter of 2012 includes an after-tax gain of $41 million for the GMIB business, an after-tax charge of $28 million for costs associated with acquisitions, and an after-tax charge of $13 million for costs associated a litigation matter in Global Health Care.