Stock-Based Compensation (Details) (USD $)	12 Months Ended									0 Months Ended				0 Months Ended		0 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Stock options	Dec. 31, 2011 Stock options	Dec. 31, 2010 Stock options	Dec. 31, 2009 Stock options	Dec. 31, 2012 Stock options Chairman	Dec. 31, 2011 Stock options Chairman	Dec. 31, 2010 Stock options Chairman	Jun. 01, 2003 2003 Plan	Jun. 01, 2003 2003 Plan Incentive stock options	Jun. 01, 2003 2003 Plan Nonqualified stock options	Jun. 09, 2011 2008 Plan	Nov. 12, 2012 2008 Plan	Nov. 12, 2008 2008 Plan Stock options	Dec. 31, 2012 2008 Plan Stock options	Nov. 12, 2008 2008 Plan Stock appreciation rights
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
Options available for future grants (in shares)															1,487,780
Exercise price of options granted, low end of range (in dollars per share)	$ 11.88	$ 11.88
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)		11,608,029	10,834,444	9,966,125			23,750	23,750
Granted (in shares)		1,466,000	1,631,000	1,868,500
Exercised (in shares)		(1,241,091)	(695,915)	(823,056)
Canceled (in shares)		(27,250)	(161,500)	(177,125)
Outstanding at the end of the period (in shares)		11,805,688	11,608,029	10,834,444	9,966,125		23,750	23,750
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)		$ 30.00	$ 28.75	$ 27.83		$ 7.95
Granted (in dollars per share)		$ 38.11	$ 35.47	$ 27.19
Exercised (in dollars per share)		$ 25.98	$ 24.02	$ 13.96
Canceled (in dollars per share)		$ 28.41	$ 26.96	$ 28.84
Outstanding at the end of the period (in dollars per share)		$ 31.44	$ 30.00	$ 28.75	$ 27.83	$ 7.95
Additional disclosures
Weighted-Average Remaining Contractual Term		3 years 11 months 19 days	4 years 6 months 11 days	5 years 1 month 28 days	5 years 8 months 1 day
Aggregate Intrinsic Value (in dollars)		$ 208,848,000	$ 100,337,000	$ 76,807,000	$ 33,038,000
Weighted-average grant-date fair value of options granted (in dollars per share)		$ 17.19	$ 16.68	$ 12.92
Exercisable
Number of Option Shares		7,892,688	7,490,154	6,586,882
Weighted-Average Exercise Price (in dollars per share)		$ 30.55	$ 30.26	$ 29.85
Aggregate intrinsic value of stock options exercised (in dollars)		23,200,000	9,500,000	15,100,000
Weighted-average remaining contractual term		3 years 5 months 19 days
Aggregate intrinsic value (in dollars)		$ 146,700,000