Stock-Based Compensation (Narrative) (Details) (USD $)	3 Months Ended				12 Months Ended	3 Months Ended			12 Months Ended	1 Months Ended		3 Months Ended				12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012 months	Mar. 31, 2013 Employee Stock Option [Member]	Mar. 31, 2012 Employee Stock Option [Member]	Mar. 31, 2013 Non-Vested Stock Unit Awards [Member]	Dec. 31, 2011 Non-Vested Stock Unit Awards [Member]	Mar. 31, 2013 Market and Service Condition Stock Units [Member]	Mar. 31, 2012 Market and Service Condition Stock Units [Member]	Mar. 31, 2013 Market and Service Condition Stock Units [Member]	Mar. 31, 2012 Market and Service Condition Stock Units [Member]	Mar. 31, 2013 2005 Plan [Member]	Mar. 31, 2013 2005 ESPP Plan [Member]	Dec. 31, 2012 2005 ESPP Plan [Member]
Shares authorized for issuance under 2005 Equity Incentive Plan														48,600,000	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														28,949,620
Shares available for grant under the 2005 Equity Incentive Plan														16,921,222
Employee Stock Purchase Plan, minimum payroll deduction as a percentage of base pay															1.00%
Employee Stock Purchase Plan, maximum payroll deduction as a percentage of base pay															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															2,779,821
stock-based compensation cost	$ 43,556,000	[1]	$ 30,557,000	[1]											$ 1,300,000	$ 1,000,000
Stock options vesting life assumed						5 years
Stock option vesting period						3 years
Stock-based compensation award vesting period, percentage of award vesting each year						33.30%		33.33%
Stock-based compensation award vesting period, percentage of award vesting each month						2.78%
Vesting period of options from acquisitions						3 years
The weighted average fair value per share of stock options granted						$ 56.97	$ 25.26
The total intrinsic value of options exercised						30,500,000	39,100,000
Total unrecognized compensation cost	69,800,000
Total unrecognized compensation cost recognition period	1 year 8 months 16 days							2 years 4 months 24 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
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%
The estimated fair value of each award												$ 89.93	$ 89.95
Stock-based compensation award vesting period, percent vested on third anniversary of grant date									100.00%
Stock-based compensation award vesting period, number of monthly installments					12
Share based awards granted and outstanding								4,658,592
Total unrecognized compensation cost related to stock-based compensation								$ 313,500,000

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