Consolidated Statement of Changes in Stockholders' Equity (Unaudited) (USD $) In Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock
Beginning Balance at Dec. 31, 2010	$ 3,606.6	$ 6.9	$ 2,354.4	$ 19.8	$ 5,369.8	$ (4,144.3)
Beginning Balance, Shares at Dec. 31, 2010		690.2
Comprehensive income:
Net income	660.7				660.7
Other comprehensive income:
Foreign currency translation adjustment	0.9			0.9
Comprehensive income	661.6			0.9	660.7
Treasury stock acquired	(2,515.7)					(2,515.7)
Changes in stockholders' equity related to employee stock plans	75.5		52.4			23.1
Changes in stockholders' equity related to employee stock plans, Shares		0.4
Ending Balance at Jun. 30, 2011	$ 1,828.0	$ 6.9	$ 2,406.8	$ 20.7	$ 6,030.5	$ (6,636.9)
Ending Balance, Shares at Jun. 30, 2011		690.6