Stock-Based Compensation (Details) (USD $)	12 Months Ended									1 Months Ended					1 Months Ended		1 Months Ended
	Dec. 31, 2011	Dec. 31, 2011 Stock options Y	Dec. 31, 2010 Stock options Y	Dec. 31, 2009 Stock options Y	Dec. 31, 2008 Stock options Y	Dec. 31, 2011 Stock options Chairman	Dec. 31, 2010 Stock options Chairman	Dec. 31, 2009 Stock options Chairman	Jun. 02, 2003 2003 Plan	Jun. 30, 2003 2003 Plan Incentive stock options	Jun. 30, 2003 2003 Plan Nonqualified stock options	Jul. 01, 2011 2008 Plan	Jun. 09, 2011 2008 Plan	Nov. 12, 2008 2008 Plan	Nov. 30, 2008 2008 Plan Stock options	Dec. 31, 2011 2008 Plan Stock options	Nov. 30, 2008 2008 Plan Stock appreciation rights	Nov. 30, 2008 2008 Plan Restricted stock and Other full value stock awards
Stock-based compensation
Number of shares of common stock available for awards									12,000,000				9,250,000
Increase in number of shares of common stock available for awards														2,350,000
Exercise price per share as a percentage of the fair market value of the Common Stock										100.00%	85.00%
Number of shares of common stock counted against the maximum shares available for grant for each share awarded under the plan												2.44			1		1	2.16
Options available for future grants (in shares)																2,929,655
Exercise price of options granted, low end of range (in dollars per share)	$ 7.95	$ 7.95
Exercise price of options granted, high end of range (in dollars per share)	$ 61.82	$ 61.82
Number of Option Shares
Outstanding at the beginning of the period (in shares)		10,834,444	9,966,125	8,804,578		23,750	23,750	23,750
Granted (in shares)		1,631,000	1,868,500	1,849,375
Exercised (in shares)		(695,915)	(823,056)	(491,078)
Canceled (in shares)		(161,500)	(177,125)	(196,750)
Outstanding at the end of the period (in shares)		11,608,029	10,834,444	9,966,125		23,750	23,750	23,750
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)		$ 28.75	$ 27.83	$ 28.27		$ 7.95
Granted (in dollars per share)		$ 35.47	$ 27.19	$ 22.32
Exercised (in dollars per share)		$ 24.02	$ 13.96	$ 11.06
Canceled (in dollars per share)		$ 26.96	$ 28.84	$ 32.27
Outstanding at the end of the period (in dollars per share)		$ 30.00	$ 28.75	$ 27.83		$ 7.95
Additional disclosures
Weighted-Average Remaining Contractual Term (in years)		4.53	5.16	5.67	6.30
Aggregate Intrinsic Value (in dollars)		$ 100,337,000	$ 76,807,000	$ 33,038,000	$ 17,677,000
Weighted-average grant-date fair value of options granted (in dollars per share)		$ 16.68	$ 12.92	$ 8.91
Exercisable
Number of Option Shares		7,490,154	6,586,882	5,872,151
Weighted-Average Exercise Price (in dollars per share)		$ 30.26	$ 29.85	$ 27.41
Aggregate intrinsic value of stock options exercised (in dollars)		9,500,000	15,100,000	8,400,000
Weighted-average remaining contractual term (in years)		4.08
Aggregate intrinsic value (in dollars)		$ 64,700,000