Consoldiated Statements of Shareholders' Equity Parenthetical (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Tax on foreign currency translation	$ 0	$ 0	$ 1
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	9	8	6
Tax on increase in net actuarial losses	(54)	(26)	(23)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	1	1	4
Tax on prior service credit (cost) from plan amendments	3	0	0
Tax on deferred derivative gains (losses)	0	1	0
Tax on reclassification adjustment for amounts recognized in income	(3)	2	0
Tax on unrealized investment gains	0	0	0
Total Shareholders' Equity
Common Treasury Stock, Shares	5,648,930	6,353,851	7,950,743	8,687,196
Tax on foreign currency translation	0	0	1
Tax on amortization of prior service cost and unrecognized gains and losses included in total benefit cost	9	8	6
Tax on increase in net actuarial losses	(44)	(28)	(21)
Tax on immediate recognition of prior service cost and unrecognized gains and losses due to curtailments, settlements, and divestitures	1	1	4
Tax on prior service credit (cost) from plan amendments	3	0	0
Tax on deferred derivative gains (losses)	0	1	0
Tax on reclassification adjustment for amounts recognized in income	(3)	2	0
Tax on unrealized investment gains	$ 0	$ 0	$ 0