Shareholders' Equity and Stock Incentive Plans, Shareholders' Equity Activity (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	$ 10,387	$ 8,757	$ 7,744
Cash dividends paid	(330)	(327)	(324)
Stock plans	358	220	218
Common shares repurchased	(43)	(141)	(17)
Tax benefit (loss) from exercise of options and restricted stock	34	(18)	(22)
Other		(21)	1
Total dividends and other transactions with shareholders	19	(287)	(144)
Treasury shares issued for acquisition		103
Comprehensive income (loss):
Net income	2,844	1,842	1,155
Other comprehensive income (loss):
Cumulative translation adjustment		(1)	(5)
Defined benefit and other postretirement plans, net	(34)	(27)	2
Net unrealized gain (loss) on investments, net of tax benefit/provision			5
Net unrealized losses on investments, tax provision (benefit)			3
Total comprehensive income	2,810	1,814	1,157
Ending balance	13,216	10,387	8,757
Common Shares [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	2,674	2,669	2,666
Cash dividends paid	0	0	0
Stock plans	9	5	3
Common shares repurchased	0	0	0
Tax benefit (loss) from exercise of options and restricted stock	0	0	0
Other		0	0
Total dividends and other transactions with shareholders	9	5	3
Treasury shares issued for acquisition		0
Comprehensive income (loss):
Net income	0	0	0
Other comprehensive income (loss):
Cumulative translation adjustment		0	0
Defined benefit and other postretirement plans, net	0	0	0
Net unrealized gain (loss) on investments, net of tax benefit/provision			0
Total comprehensive income	0	0	0
Ending balance	2,683	2,674	2,669
Paid-in Capital in Excess of Par Value [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	339	411	484
Cash dividends paid	0	0	0
Stock plans	82	(37)	(51)
Common shares repurchased	0	0	0
Tax benefit (loss) from exercise of options and restricted stock	34	(18)	(22)
Other		0	0
Total dividends and other transactions with shareholders	116	(55)	(73)
Treasury shares issued for acquisition		(17)
Comprehensive income (loss):
Net income	0	0	0
Other comprehensive income (loss):
Cumulative translation adjustment		0	0
Defined benefit and other postretirement plans, net	0	0	0
Net unrealized gain (loss) on investments, net of tax benefit/provision			0
Total comprehensive income	0	0	0
Ending balance	455	339	411
Treasury Stock [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	(4,771)	(5,002)	(5,251)
Cash dividends paid	0	0	0
Stock plans	267	252	266
Common shares repurchased	(43)	(141)	(17)
Tax benefit (loss) from exercise of options and restricted stock	0	0	0
Other		0	0
Total dividends and other transactions with shareholders	224	111	249
Treasury shares issued for acquisition		120
Comprehensive income (loss):
Net income	0	0	0
Other comprehensive income (loss):
Cumulative translation adjustment		0	0
Defined benefit and other postretirement plans, net	0	0	0
Net unrealized gain (loss) on investments, net of tax benefit/provision			0
Total comprehensive income	0	0	0
Ending balance	(4,547)	(4,771)	(5,002)
Retained Earnings [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	12,371	10,863	10,041
Cash dividends paid	(330)	(327)	(324)
Stock plans	0	0	0
Common shares repurchased	0	0	0
Tax benefit (loss) from exercise of options and restricted stock	0	0	0
Other		0	1
Total dividends and other transactions with shareholders	(330)	(327)	(323)
Treasury shares issued for acquisition		0
Comprehensive income (loss):
Net income	2,839	1,835	1,145
Other comprehensive income (loss):
Cumulative translation adjustment		0	0
Defined benefit and other postretirement plans, net	0	0	0
Net unrealized gain (loss) on investments, net of tax benefit/provision			0
Total comprehensive income	2,839	1,835	1,145
Ending balance	14,880	12,371	10,863
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	(240)	(213)	(215)
Cash dividends paid	0	0	0
Stock plans	0	0	0
Common shares repurchased	0	0	0
Tax benefit (loss) from exercise of options and restricted stock	0	0	0
Other		0	0
Total dividends and other transactions with shareholders	0	0	0
Treasury shares issued for acquisition		0
Comprehensive income (loss):
Net income	0	0	0
Other comprehensive income (loss):
Cumulative translation adjustment		(1)	(5)
Defined benefit and other postretirement plans, net	(33)	(26)	2
Net unrealized gain (loss) on investments, net of tax benefit/provision			5
Total comprehensive income	(33)	(27)	2
Ending balance	(273)	(240)	(213)
Noncontrolling Interest in Consolidated Subsidiaries [Member]
Increase (decrease) in shareholders' equity [Roll Forward]
Beginning balance	14	29	19
Cash dividends paid	0	0	0
Stock plans	0	0	0
Common shares repurchased	0	0	0
Tax benefit (loss) from exercise of options and restricted stock	0	0	0
Other		(21)	0
Total dividends and other transactions with shareholders	0	(21)	0
Treasury shares issued for acquisition		0
Comprehensive income (loss):
Net income	5	7	10
Other comprehensive income (loss):
Cumulative translation adjustment		0	0
Defined benefit and other postretirement plans, net	(1)	(1)	0
Net unrealized gain (loss) on investments, net of tax benefit/provision			0
Total comprehensive income	4	6	10
Ending balance	$ 18	$ 14	$ 29