FINANCIAL INFORMATION Revised Consolidated Balance Sheets (Details) (USD $)	Mar. 31, 2012		Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2012 Q1 2012 Revised Financial Statements [Member]	Dec. 31, 2011 Q1 2012 Revised Financial Statements [Member]	Dec. 31, 2010 Q1 2012 Revised Financial Statements [Member]	Dec. 31, 2009 Q1 2012 Revised Financial Statements [Member]	Dec. 31, 2011 As Reported [Member]	Dec. 31, 2010 As Reported [Member]	Dec. 31, 2011 As Revised [Member]	Dec. 31, 2010 As Revised [Member]
Accrued withholding taxes understatement						$ 3,800,000
Interest and penalties on withholding tax understatement						1,100,000	1,000,000
Interest on withholding tax understatement						700,000	600,000
Penalties on withholding tax understatement						400,000	400,000
Increase in accumulated deficit							(7,900,000)	(8,200,000)	(6,300,000)
Current assets:
Cash and cash equivalents	49,681,000		32,855,000	33,220,000	42,782,000					32,855,000	42,782,000	32,855,000	42,782,000
Accounts receivable	87,506,000		104,305,000							104,305,000	101,171,000	104,305,000	102,631,000
Inventories	103,666,000		111,397,000							111,833,000	108,357,000	111,397,000	106,785,000
Deferred tax assets, net	1,482,000		1,480,000							1,480,000	1,068,000	1,480,000	757,000
Prepaid expenses	9,902,000		7,652,000							7,652,000	7,688,000	7,652,000	7,688,000
Other current assets	13,279,000		14,405,000							14,509,000	15,701,000	14,405,000	15,701,000
Total current assets	265,516,000		272,094,000							272,634,000	276,767,000	272,094,000	276,344,000
Property and equipment, net	52,213,000		53,487,000							53,487,000	62,519,000	53,487,000	62,519,000
Intangible assets, net	16,387,000		18,524,000							18,524,000	29,750,000	18,524,000	29,750,000
Goodwill	246,884,000	[1]	246,592,000							246,398,000	246,997,000	246,592,000	246,997,000
Other assets	9,526,000		11,568,000							11,568,000	10,538,000	11,568,000	10,538,000
Total assets	590,526,000		602,265,000							602,611,000	626,571,000	602,265,000	626,148,000
Current liabilities:
Accounts payable	37,188,000		42,533,000							42,533,000	47,340,000	42,533,000	47,104,000
Accrued compensation and benefits	22,873,000		31,750,000							31,350,000	38,686,000	31,750,000	38,118,000
Accrued expenses and other current liabilities	32,503,000		35,109,000							34,174,000	40,986,000	35,109,000	42,059,000
Income taxes payable	8,254,000		8,951,000							3,898,000	4,640,000	8,951,000	9,823,000
Deferred revenues	57,908,000		45,768,000							45,768,000	43,634,000	45,768,000	44,173,000
Total current liabilities	158,726,000		164,111,000							157,723,000	175,286,000	164,111,000	181,277,000
Long-term liabilities	29,121,000		27,885,000							27,885,000	24,675,000	27,885,000	24,675,000
Total liabilities	187,847,000		191,996,000							185,608,000	199,961,000	191,996,000	205,952,000
Stockholders' equity:
Common stock	423,000		423,000							423,000	423,000	423,000	423,000
Additional paid-in capital	1,021,880,000		1,019,200,000							1,018,604,000	1,005,198,000	1,019,200,000	1,006,029,000
Accumulated deficit	(547,575,000)		(532,478,000)							(524,530,000)	(495,254,000)	(532,478,000)	(503,485,000)
Treasury stock at cost, net of reissuances	(79,899,000)		(82,301,000)							(82,301,000)	(91,025,000)	(82,301,000)	(91,025,000)
Accumulated other comprehensive income	7,850,000		5,425,000							4,807,000	7,268,000	5,425,000	8,254,000
Total stockholders' equity	402,679,000		410,269,000							417,003,000	426,610,000	410,269,000	420,196,000
Total liabilities and stockholders' equity	$ 590,526,000		$ 602,265,000							$ 602,611,000	$ 626,571,000	$ 602,265,000	$ 626,148,000

[1] (a) The March 31, 2012 gross and net goodwill amounts include total foreign currency translation increases of approximately $0.3 million from the December 31, 2011 amounts.