Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended	9 Months Ended		3 Months Ended			6 Months Ended	9 Months Ended	12 Months Ended	3 Months Ended			9 Months Ended						9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Stock Options	Mar. 31, 2014 Stock Options	Sep. 30, 2013 Stock Options	Jun. 30, 2014 Stock Options	Sep. 30, 2014 Stock Options	Dec. 31, 2013 Stock Options	Sep. 30, 2014 Restricted Shares	Mar. 31, 2014 Restricted Shares	Sep. 30, 2013 Restricted Shares	Sep. 30, 2014 Restricted Shares	Sep. 30, 2013 Restricted Shares	Sep. 30, 2014 2000 Employee Option Plan	Sep. 30, 2014 2009 Employee Option Plan	May 31, 2014 2009 Employee Option Plan	Apr. 30, 2014 2009 Employee Option Plan	Sep. 30, 2014 2000 Employee Option Plan and 2009 Employee Option Plan	Sep. 30, 2014 2004 Directors Option Plan	Sep. 30, 2014 2012 Directors Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of additional stock options that can be granted (in shares)																	0
Common Stock reserved for issuance																			58,000,000	32,000,000
Shares available for the granting of additional stock options																		24,788,660				140,000	171,922
Options ratable vesting period																					5 years	3 years
Options exercisable period																					10 years	10 years
Number of additional stock options expected to be granted (in shares)																						0
Expense incurred for stock-based compensation plans (in dollars)	$ 10,133	$ 9,413		$ 29,382	$ 19,432
Expense incurred for stock-based compensation plans, net of tax (in dollars)	7,512	6,940		21,649	(26,584)
Stock option activity
Options outstanding at the beginning of the period (in shares)						29,866,530	26,844,452		26,844,452	26,844,452
Options granted (in shares)							65,000		6,047,000	108,000
Options exercised (in shares)							(629,932)		(2,257,950)	(1,483,440)
Options forfeited (in shares)							(102,920)		(99,120)	(94,320)
Options outstanding at the end of the period (in shares)						28,396,770	26,176,600		29,866,530	28,396,770	26,844,452
Vested and non-vested options expected to vest at the end of the period (in shares)						25,649,402				25,649,402
Exercisable at the end of the period (in shares)						11,775,650				11,775,650
Weighted Average Exercise Price
Weighted average exercise price, options outstanding at the beginning of the period (in dollars per share)						$ 30.90	$ 25.90		$ 25.90	$ 25.90
Weighted average exercise price, options granted (in dollars per share)							$ 44.57		$ 47.72	$ 48.77
Weighted average exercise price, options exercised (in dollars per share)							$ 20.21		$ 19.90	$ 20.47
Weighted average exercise price, options forfeited (in dollars per share)							$ 29.90		$ 32.61	$ 36.39
Weighted average exercise price, options outstanding at the end of the period (in dollars per share)						$ 31.49	$ 26.07		$ 30.90	$ 31.49	$ 25.90
Weighted average exercise price, vested and non-vested options expected to vest (in dollars per share)						$ 31.10				$ 31.10
Weighted average exercise price, exercisable (in dollars per share)						$ 23.11				$ 23.11
Weighted Average Remaining Contractual Term
Weighted average remaining contractual term of options outstanding			7 years 5 months 16 days	7 years 3 months 26 days			6 years 10 months 21 days				7 years 29 days
Weighted average remaining contractual term of options vested options and non-vested expected to vest										7 years 2 months 23 days
Weighted average remaining contractual term of options exercisable										5 years 8 months 27 days
Aggregate Intrinsic Value
Aggregate intrinsic value of options outstanding (in dollars)						523,618	517,164		515,908	523,618	501,706
Aggregate intrinsic value of options, vested and non-vested options expected to vest (in dollars)						483,163				483,163
Aggregate intrinsic value of options exercisable (in dollars)						315,886				315,886
Status of the Company's non-vested options and changes during the year
Non-vested options at the beginning of the period (in shares)						16,633,780	16,033,842		16,033,842	16,033,842
Non-vested options, options granted (in shares)							65,000		6,047,000	108,000
Non-vested options, options vested (in shares)							(14,000)		(5,296,022)	(26,340)
Non-vested options, options forfeited (in shares)							(102,920)		(99,120)	(94,320)
Non-vested options at the end of the period (in shares)						16,621,120	15,981,922		16,633,780	16,621,120	16,033,842
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)						$ 7.97	$ 7.39		$ 7.39	$ 7.39
Weighted average fair value at grant date, options granted (in dollars per share)							$ 10.62		$ 8.62	$ 8.85
Weighted average fair value at grant date, options vested (in dollars per share)							$ 8.49		$ 6.98	$ 8.33
Weighted average fair value at grant date, options forfeited (in dollars per share)							$ 7.41		$ 7.66	$ 8.00
Weighted average fair value at the grant date, options outstanding at the end of the period (in dollars per share)						$ 7.98	$ 7.40		$ 7.97	$ 7.98	$ 7.39
Total intrinsic value of stock options exercised (in dollars)				123,911	91,091	45,458		16,456
Total fair value of stock options vested (in dollars)				37,277	33,830	219		49
Total compensation cost related to non-vested options not yet recognized (in dollars)						104,618	104,618			104,618		562			562
Weighted average expected amortization period							3 years 7 months 2 days			3 years 7 months 2 days			7 months 24 days		7 months 6 days
Number of restricted shares issued												18,340		25,648		34,090
Weighted-average grant date fair value of restricted shares (in dollars per share)												$ 47.72		$ 39.00		$ 26.89
Total compensation cost related to non-vested restricted shares not yet recognized (in dollars)													$ 562