CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012 Scenario, Actual [Member]
Cash flows from operating activities:
Net income	$ 8,265,000	$ 16,065,000
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	6,135,000	7,872,000
Recovery of doubtful accounts	(36,000)	(111,000)
Gain on sales of assets	(125,000)	0
Stock-based compensation expense	2,077,000	2,911,000
Non-cash interest expense	73,000	73,000
Foreign currency transaction losses	44,000	(1,028,000)
Provision for deferred taxes	3,000	372,000
Changes in operating assets and liabilities, excluding initial effects of acquisitions:
Accounts receivable	11,366,000	18,307,000
Inventories	2,501,000	6,550,000
Prepaid expenses and other current assets	(374,000)	411,000
Accounts payable	(5,383,000)	(5,376,000)
Accrued expenses, compensation and benefits and other liabilities	(7,532,000)	(10,837,000)
Income taxes payable	(878,000)	1,384,000
Deferred revenues	(17,546,000)	(17,850,000)
Net cash provided by (used in) operating activities	(1,410,000)	18,743,000
Cash flows from investing activities:
Purchases of property and equipment	(2,126,000)	(3,589,000)
Proceeds from sales of assets	125,000	0
Increase in other long-term assets	(8,000)	(366,000)
Net cash used in investing activities	(2,009,000)	(3,955,000)
Cash flows from financing activities:
Proceeds from the issuance of common stock under employee stock plans, net	176,000	282,000
Common stock repurchases for tax withholdings for net settlement of equity awards	(181,000)	(454,000)
Proceeds from revolving credit facilities	0	1,000,000
Payments on revolving credit facilities	0	(1,000,000)
Net cash provided by financing activities	(5,000)	(172,000)
Effect of exchange rate changes on cash and cash equivalents	(2,460,000)	2,210,000
Net increase (decrease) in cash and cash equivalents	(5,884,000)	16,826,000
Cash and cash equivalents at beginning of period	70,390,000	32,855,000
Cash and cash equivalents at end of period	64,506,000	49,681,000
Cash paid for income taxes, net of refunds	476,000	714,000
Cash paid for interest	$ 262,000	$ 270,000