Net Income Per Share Attributable To Citrix Systems, Inc. Stockholders (Net Income Per Share Basic And Diluted) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income Per Share Attributable To Citrix Systems, Inc. Stockholders
Net income attributable to Citrix Systems, Inc. stockholders	$ 114,029	$ 108,699	$ 78,245	$ 92,006	$ 68,267	$ 92,176	$ 81,944	$ 73,503	$ 352,547	$ 356,322	$ 277,065
Denominator for basic earnings per share — weighted-average shares outstanding									186,722	187,315	185,959
Employee stock awards									2,407	3,326	4,376
Denominator for diluted earnings per share — weighted-average shares outstanding									189,129	190,641	190,335
Net income per share attributable to Citrix Systems, Inc. stockholders — basic	$ 0.61	$ 0.59	$ 0.42	$ 0.49	$ 0.37	$ 0.49	$ 0.44	$ 0.39	$ 1.89	$ 1.90	$ 1.49
Net income per share attributable to Citrix Systems, Inc. stockholders — diluted	$ 0.60	$ 0.58	$ 0.41	$ 0.49	$ 0.36	$ 0.49	$ 0.43	$ 0.38	$ 1.86	$ 1.87	$ 1.46
Anti-dilutive weighted-average shares									3,464	2,576	2,288