Fair Value Measurements (Summary Of Liabilities Measured At Fair Value On Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Details) (USD $) In Thousands	Jun. 30, 2011		Dec. 31, 2010		Jun. 30, 2010		Dec. 31, 2009
Fair Value Measurements
Total, beginning of the period	$ 11,513	[1]	$ 8,515	[1]	$ 4,000	[1]	$ 4,000	[1]
Contingent consideration	5,700	[1]
Payment of contingent consideration	(2,702)	[1]
Total, end of the period	$ 11,513	[1]	$ 8,515	[1]	$ 4,000	[1]	$ 4,000	[1]

[1] We enter into earn-out agreements with the shareholders of certain companies we acquire. The earn-out contingent payments are typically based on the acquired company's products' total revenue or sales growth over a specified period after the acquisition date. This also includes contingent consideration relating to our purchase of intellectual property. During the second quarter of 2011, we separately purchased intellectual property and entered into an agreement whereby the former owner has the opportunity to earn an additional amount contingent upon his achievement of certain technology milestones.