STOCKHOLDERS' EQUITY (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Total stock-based compensation expense, excluding acquisition-related charges
Stock-based compensation expense
Total stock-based compensation expense, before income taxes	$ 19,327	$ 18,889
Tax benefit	(2,790)	(2,644)
Total stock-based compensation expense, net of income taxes	16,537	16,245
Cost of revenue
Stock-based compensation expense
Total stock-based compensation expense, before income taxes	2,255	2,293
Research and development
Stock-based compensation expense
Total stock-based compensation expense, before income taxes	6,763	5,982
Selling, general and administrative
Stock-based compensation expense
Total stock-based compensation expense, before income taxes	$ 10,309	$ 10,614