Business Segment Information (Financial Information By Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Segment Reporting Information [Line Items]
Revenue	$ 407,007	$ 379,017	$ 365,609	$ 344,165	$ 339,631	$ 308,069	$ 294,635	$ 276,154	$ 1,495,798	[1]	$ 1,218,489	[1]	$ 966,984	[1]
Contribution margin									645,559		488,665		395,449
Gross accounts receivable	257,235				188,892				257,235		188,892		164,510
Americas [Member]
Segment Reporting Information [Line Items]
Revenue									756,074	[1]	656,432	[1]	536,682	[1]
Contribution margin									315,297		261,625		216,739
Gross accounts receivable	102,973				83,350				102,973		83,350		70,173
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue									376,579	[1]	302,118	[1]	240,226	[1]
Contribution margin									153,842		108,296		90,143
Gross accounts receivable	82,259				60,622				82,259		60,622		53,731
APAC [Member]
Segment Reporting Information [Line Items]
Revenue									363,145	[1]	259,939	[1]	190,076	[1]
Contribution margin									176,420		118,744		88,567
Gross accounts receivable	72,003				44,920				72,003		44,920		40,606
United States [Member]
Segment Reporting Information [Line Items]
Revenue									$ 654,200		$ 568,700		$ 460,600
Total Revenue [Member]
Segment Reporting Information [Line Items]
% of measurement value	100.00%				100.00%				100.00%		100.00%		100.00%
Total Revenue [Member] | Americas [Member]
Segment Reporting Information [Line Items]
% of measurement value	51.00%				54.00%				51.00%		54.00%		55.00%
Total Revenue [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
% of measurement value	25.00%				25.00%				25.00%		25.00%		25.00%
Total Revenue [Member] | APAC [Member]
Segment Reporting Information [Line Items]
% of measurement value	24.00%				21.00%				24.00%		21.00%		20.00%
Segment Revenue [Member]
Segment Reporting Information [Line Items]
% of measurement value	43.00%				40.00%				43.00%		40.00%		41.00%
Segment Revenue [Member] | Americas [Member]
Segment Reporting Information [Line Items]
% of measurement value	42.00%				40.00%				42.00%		40.00%		40.00%
Segment Revenue [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
% of measurement value	41.00%				36.00%				41.00%		36.00%		38.00%
Segment Revenue [Member] | APAC [Member]
Segment Reporting Information [Line Items]
% of measurement value	49.00%				46.00%				49.00%		46.00%		47.00%
Total Gross Accounts Receivable [Member]
Segment Reporting Information [Line Items]
% of measurement value	100.00%				100.00%				100.00%		100.00%		100.00%
Total Gross Accounts Receivable [Member] | Americas [Member]
Segment Reporting Information [Line Items]
% of measurement value	40.00%				44.00%				40.00%		44.00%		43.00%
Total Gross Accounts Receivable [Member] | EMEA [Member]
Segment Reporting Information [Line Items]
% of measurement value	32.00%				32.00%				32.00%		32.00%		33.00%
Total Gross Accounts Receivable [Member] | APAC [Member]
Segment Reporting Information [Line Items]
% of measurement value	28.00%				24.00%				28.00%		24.00%		24.00%

[1] Net revenues in the United States were $654.2 million, $568.7 million, and $460.6 million for the years ended December 31, 2011, 2010, and 2009, respectively. United States and China, individually, accounted for more than 10% of the Company's revenue in 2011. No individual country outside the United States accounted for more than 10% of the Company's revenues in 2010 or 2009.