Stock-Based Compensation (Narrative) (Details) (USD $)	3 Months Ended				9 Months Ended				3 Months Ended		9 Months Ended		1 Months Ended		9 Months Ended				9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013 plan		Sep. 30, 2012		Sep. 30, 2013 plan		Sep. 30, 2012		Sep. 30, 2013 Employee Stock Option [Member]	Sep. 30, 2012 Employee Stock Option [Member]	Sep. 30, 2013 Employee Stock Option [Member]	Sep. 30, 2012 Employee Stock Option [Member]	Mar. 31, 2013 Market and Service Condition Stock Units [Member]	Mar. 31, 2012 Market and Service Condition Stock Units [Member]	Sep. 30, 2013 Market and Service Condition Stock Units [Member]	Sep. 30, 2013 Non-Vested Stock Unit Awards [Member]	Sep. 30, 2012 Non-Vested Stock Unit Awards [Member] installment	Sep. 30, 2013 2005 Plan [Member]	Sep. 30, 2013 2005 Plan [Member] Minimum [Member]	Sep. 30, 2013 2005 Plan [Member] Maximum [Member]	Sep. 30, 2013 2005 ESPP Plan [Member]	Sep. 30, 2012 2005 ESPP Plan [Member]	Sep. 30, 2013 2005 ESPP Plan [Member] frequency	Sep. 30, 2012 2005 ESPP Plan [Member]	Sep. 30, 2013 2005 ESPP Plan [Member] Minimum [Member]	Sep. 30, 2013 2005 ESPP Plan [Member] Maximum [Member]	Sep. 30, 2013 Vesting on first anniversary of date of grant [Member] Employee Stock Option [Member]	Sep. 30, 2013 Vesting in equal monthly installments after first anniversary of date of grant [Member] Employee Stock Option [Member]	Sep. 30, 2013 Annual vesting on each anniversary [Member] Non-Vested Stock Unit Awards [Member]	Sep. 30, 2013 Vesting on third anniversary [Member] Non-Vested Stock Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans offered	2				2
Shares authorized for issuance under 2005 Equity Incentive Plan																		48,600,000			10,000,000		10,000,000
Ownership percentage of company where incentive stock options must be granted with an exercise price greater than fair market value																				10.00%
Exercise price of incentive stock options granted to individuals owning 10% or more of the Company's common stock, as a percentage of fair market value of common stock on the date of grant																			110.00%
Shares reserved for issuance under the 2005 Equity Incentive Plan																		27,409,886
Shares available for grant under the 2005 Equity Incentive Plan																		16,965,265
Employee Stock Purchase Plan, maximum purchase frequency per year																							2
Employee Stock Purchase Plan, payment period																							6 months
Employee Stock Purchase Plan, minimum payroll deduction as a percentage of base pay																									1.00%	10.00%
Employee Stock Purchase Plan, maximum number of shares per period that employees can purchase																							12,000
Employee Stock Purchase Plan, purchase price as a percentage of fair market value																							85.00%
Employee Stock Purchase Plan, employee disqualification, ownership percent of outstanding stock																							5.00%
Employee Stock Purchase Plan, total shares issued under plan																					2,991,834		2,991,834
stock-based compensation cost	$ 45,893,000	[1]	$ 40,103,000	[1]	$ 137,306,000	[1]	$ 108,922,000	[1]													$ 1,100,000	$ 1,100,000	$ 3,700,000	$ 3,000,000
Stock options vesting life assumed											5 years
Stock option vesting period											3 years
Award vesting percentage																											33.30%	2.78%	33.33%	100.00%
Vesting period of options from acquisitions											3 years
The total intrinsic value of options exercised									28,700,000	39,800,000	70,200,000	117,000,000
Total unrecognized compensation cost									41,000,000		41,000,000
Total unrecognized compensation cost recognition period											1 year 4 months 18 days					2 years 0 months 8 days
Non-vested stock unit awards granted to senior level employees													399,029	418,809
Period to determine actual stock grant following end of performance period														60 days
Performance period for grants														3 years
Maximum percentage of market and service condition stock units that will ultimately vest															200.00%
Percentage that Company's return exceeds indexed return															40.00%
Percentage that Company's return underperforms index															20.00%
Percent of award issued if return is negative but index is met															75.00%
Number of shares represented by each non-vested stock unit upon vesting																1
The estimated fair value of each award																$ 89.93	$ 89.95
Stock-based compensation award vesting period, number of monthly installments																	12
Share based awards granted and outstanding																4,440,852
Total unrecognized compensation cost related to stock-based compensation																$ 248,100,000

[1] Represents expenses presented to management on a consolidated basis only and not allocated to the operating segments.