Common Stock, Preferred Stock and Equity Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 Y	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award
Common stock, shares authorized	300,000,000	300,000,000
Common Stock, Votes Per Share	1
Awards Outstanding (shares)	22,075,594
Additional awards authorized for grant (in shares)	5,751,677
Grant price of outstanding restricted stock and restricted stock units (in dollars per share)	$ 0.01
Outstanding and exercisable options
Stock options outstanding at beginning of period (in shares)	20,923,000
Stock options granted (in shares)	6,043,000
Stock options exercised (in shares)	(5,856,000)
Stock options forfeited (in shares)	(1,310,000)
Stock options expired (in shares)	(74,000)
Stock options outstanding at end of period (in shares)	19,726,000	20,923,000
Stock options exercisable at end of period (in shares)	10,849,000
Total exercisable or expected to vest, stock options (in shares)	18,782,000
Weighted average Exercise Price
Weighted-average exercise price outstanding at beginning of period (usd per share)	$ 34.23
Weighted average exercise price, granted (usd per share)	$ 43.80
Weighted average exercise price, exercised (usd per share)	$ 29.51
Weighted average exercise price, forfeited (usd per share)	$ 41.01
Weighted average exercise price, expired (usd per share)	$ 39.47
Weighted-average exercise price outstanding at end of period (usd per share)	$ 38.09	$ 34.23
Weighted average exercise price exercisable at the end of the period (usd per share)	$ 34.54
Total exercisable or expected to vest, weighted average exercise price (usd per share)	$ 37.83
Weighted-average Remaining Contractual Life
Weighted-average Remaining Contractual Life, outstanding (in years)	7.15
Weighted-average Remaining Contractual Life, exercisable (in years)	5.93
Weighted-average Remaining Contractual Life, total exercisable or expected to vest (in years)	7.06
Aggregate Intrinsic Value
Aggregate intrinsic value, outstanding	$ 107,016,000
Aggregate intrinsic value, exercisable	84,297,000
Aggregate intrinsic value, total exercisable or expected to vest	104,931,000
Preferred stock, shares authorized	1,000,000	1,000,000
Total Intrinsic Value and Cash Received
Market price	$ 41.20
Total intrinsic value of stock options exercised	148,700,000	90,500,000	10,500,000
Total cash received from employees as a result of employee stock option exercises	$ 172,800,000	$ 109,600,000	$ 22,200,000
2006 Stock and Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Awards Outstanding (shares)	20,551,584
Additional awards authorized for grant (in shares)	5,751,677
Approved increase in number of shares authorized for issuance (in shares)	3,000,000		12,000,000
1996 Stock and Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Awards Outstanding (shares)	1,524,010
Additional awards authorized for grant (in shares)	0
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Approved increase in number of shares authorized for issuance (in shares)	2,500,000