Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2011 Year Site	Jun. 30, 2011 Year	Mar. 31, 2011 Year	Sep. 30, 2010	Sep. 30, 2011 Segment Jurisdiction Year statement Plan Site	Sep. 30, 2010	Dec. 31, 2010 Year
Share-based Compensation Arrangement by Share-based Payment Award
Expense incurred for stock-based compensation plans (in dollars)	$ 7,630			$ 6,965	$ 21,011	$ 18,580
Expense incurred for stock-based compensation plans, net of tax (in dollars)	5,545			5,376	15,156	14,269
Stock option activity
Options outstanding at the beginning of the period (in shares)	14,247,292	12,126,570	12,706,324		12,706,324
Options granted (in shares)		2,506,350	35,000
Options exercised (in shares)	(82,067)	(303,328)	(576,454)
Options forfeited (in shares)	(39,400)	(82,300)	(38,300)
Options outstanding at the end of the period (in shares)	14,125,825	14,247,292	12,126,570		14,125,825
Vested and non-vested expected to vest at the end of the period (in shares)	13,102,554				13,102,554
Exercisable at the end of the period (in shares)	6,450,449				6,450,449
Weighted Average Exercise Price
Weighted average exercise price, options outstanding at the beginning of the period (in dollars per share)	$ 37.92	$ 34.54	$ 33.93		$ 33.93
Weighted average exercise price, options granted (in dollars per share)		$ 53.48	$ 53.41
Weighted average exercise price, options exercised (in dollars per share)	$ 34.16	$ 31.42	$ 20.68		$ 34.16
Weighted average exercise price, options forfeited (in dollars per share)	$ 40.93	$ 38.10	$ 37.49		$ 40.93
Weighted average exercise price, options outstanding at the end of the period (in dollars per share)	$ 37.93	$ 37.92	$ 34.54		$ 37.93
Weighted average exercise price, vested and non-vested expected to vest (in dollars per share)	$ 37.46				$ 37.46
Weighted average exercise price, exercisable (in dollars per share)	$ 31.39				$ 31.39
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term of options outstanding (in years)	7.13	7.38	7.08		7.13		7.18
Weighted average remaining contractual term of options vested and non-vested expected to vest (in years)					7.02
Weighted average remaining contractual term of options exercisable (in years)					5.64
Aggregate Intrinsic Value
Aggregate intrinsic value of options outstanding (in dollars)	86,994	228,952	240,698		86,994		239,534
Aggregate intrinsic value of options, vested and non-vested expected to vest (in dollars)	84,581				84,581
Aggregate intrinsic value of options exercisable (in dollars)	66,899				66,899
Status of the Company's non-vested options and changes during the year
Non-vested options at the beginning of the period (in shares)	7,718,376	7,620,676	7,623,976		7,623,976
Non-vested options, options granted (in shares)		2,506,350	35,000
Non-vested options, options vested (in shares)	(3,600)	(2,326,350)
Non-vested options, options forfeited (in shares)	(39,400)	(82,300)	(38,300)
Non-vested options at the end of the period (in shares)	7,675,376	7,718,376	7,620,676		7,675,376
Weighted Average Fair Value at Grant Date
Weighted average fair value at the grant date, options outstanding at the beginning of the period (in dollars per share)	$ 13.41	$ 12.80	$ 12.78		$ 12.78
Weighted average fair value at grant date, options granted (in dollars per share)		$ 14.15	$ 16.98
Weighted average fair value at grant date, options vested (in dollars per share)	$ 12.65	$ 12.23
Weighted average fair value at grant date, options forfeited (in dollars per share)	$ 13.18	$ 12.82	$ 12.63
Weighted average fair value at the grant date, options outstanding at the end of the period (in dollars per share)	$ 13.41	$ 13.41	$ 12.80		$ 13.41
Total intrinsic value of stock options exercised (in dollars)	1,519			13,566	27,921	23,265
Total fair value of stock options vested (in dollars)	46			31	28,492	23,698
Total compensation cost related to non-vested options not yet recognized (in dollars)	$ 81,331				$ 81,331
Weighted average expected amortization period (in years)					3.45
2009 Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Shares available for the granting of additional stock options (in shares)	7,656,050				7,656,050
2000 Option Plan and 2009 Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Options ratable vesting period (in years)					5Y
Options exercisable period (in years)					10
Directors Option Plan
Share-based Compensation Arrangement by Share-based Payment Award
Shares available for the granting of additional stock options (in shares)	80,000				80,000
Options ratable vesting period (in years)					3Y
Options exercisable period (in years)					10