Schedule I Condensed Financial Information Parent Company Statements of Shareholders' Equity Parenthetical (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements [Line Items]
Tax on foreign currency translation	$ 0	$ 0	$ 0
Tax on reclassification adjustment for amounts recognized in income	0	0	0
Defined benefit plans:
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	10	9	8
Tax on decrease (increase) in net actuarial losses	34	(54)	(26)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	1	1	1
Tax on prior service credit (cost) from plan amendments	0	3	0
Tax on deferred derivative gains (losses)	1	0	1
Tax on reclassification adjustment for amounts recognized in income	0	(3)	2
Tax on unrealized investment gains	0	0	0
Parent Company
Condensed Financial Statements [Line Items]
Common Treasury Stock, Shares	3,136,663	5,648,930	6,353,851	7,950,743
Tax on foreign currency translation	0	0	0
Tax on reclassification adjustment for amounts recognized in income	0	0	0
Defined benefit plans:
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	9	9	8
Tax on decrease (increase) in net actuarial losses	33	(44)	(28)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	1	1	1
Tax on prior service credit (cost) from plan amendments	0	3	0
Tax on deferred derivative gains (losses)	1	0	1
Tax on reclassification adjustment for amounts recognized in income	0	(3)	2
Tax on unrealized investment gains	$ 0	$ 0	$ 0