Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		6 Months Ended				1 Months Ended	6 Months Ended
	Feb. 28, 2011	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	May 19, 2011	Feb. 22, 2011	May 31, 2011 Non Employee [Member]	Jun. 30, 2011 Restricted Stock And Restricted Stock Units [Member]	Jun. 30, 2011 Restricted stock [Member]	Jun. 30, 2011 Performance-base restricted stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock granted	234,620							8,505	374,425		131,300
Period of option vested over grant date				Options generally vest over a three-year period from the grant date						Restricted stock awards vest on the third anniversary of the date of grant
Stock option granted	2,255,322			2,277,946				22,624
Stock-Based Compensation (Textuals) [Abstract]
Earlier authorized shares under stock based compensation				25,500,000
Remaining shares available for future grants under the Plan		5,647,612		5,647,612
Total stock-based compensation compensation arrangements under the Plan		$ 19	$ 16	$ 36	$ 33
Total income tax benefit stock-based compensation arrangements under the Plan		$ 6	$ 5	$ 11	$ 10
Stock options granted, exercise price						$ 67.93	$ 79.80
Performance based restricted stock awards grants in period percent				100.00%
The performance based restricted stock awards vested, number of months				36 months