CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Millions, except Share data	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Comprehensive Income
Balance at Dec. 31, 2010	$ 10,203	$ 0	$ 12,353	$ (2,194)	$ 57	$ (13)
Balance (in shares) at Dec. 31, 2010		1,382		(199)
Components of comprehensive income:
Net income	838				838		838
Foreign currency translation adjustment	40					40	40
Unrealized appreciation (depreciation) on investments, net of taxes	2					2	2
Total comprehensive income	880						880
Issuance of common stock pursuant to employee stock options and restricted stock rights	26		26
Issuance of common stock pursuant to employee stock options and restricted stock rights (in shares)		4
Stock-based compensation expense related to employee stock options and restricted stock rights	51		51
Dividends ($0.165 per common share)	(194)				(194)
Shares repurchased	(501)			(501)
Shares repurchased (in shares)				(45)
Retirement of treasury shares			(2,695)	2,695
Retirement of treasury shares (in shares)		(244)		244
Balance at Jun. 30, 2011	$ 10,465	$ 0	$ 9,735	$ 0	$ 701	$ 29
Balance (in shares) at Jun. 30, 2011		1,142		0