FINANCIAL INFORMATION Revised Consolidated Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 22,244	$ 48,203	$ 64,506	$ 70,390
Accounts receivable	58,420	56,770
Inventories	58,246	60,122
Deferred tax assets, net	525	522
Prepaid expenses	10,052	7,778
Other current assets	15,625	17,493
Total current assets	165,112	190,888
Property and equipment, net	34,373	35,186
Intangible assets, net	3,679	4,260
Other assets	2,401	2,393
Total assets	207,987	235,142
Current liabilities:
Accounts payable	29,846	33,990
Accrued compensation and benefits	22,598	30,342
Accrued expenses and other current liabilities	31,560	41,273
Income taxes payable	6,003	6,875
Deferred revenues	209,164	211,403
Total current liabilities	299,171	323,897
Long-term liabilities	14,516	14,586
Total liabilities	556,879	594,477
Stockholders' equity:
Common stock	423	423
Additional paid-in capital	1,043,881	1,043,384
Accumulated deficit	(1,327,631)	(1,336,526)
Treasury stock at cost, net of reissuances	(71,885)	(72,543)
Accumulated other comprehensive income	6,320	5,927
Total stockholders' equity	(348,892)	(359,335)
Total liabilities and stockholders' equity	$ 207,987	$ 235,142