Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 4,898,000	$ 823,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for doubtful accounts	726,000	556,000
Depreciation and amortization	4,301,000	3,377,000
Deferred income taxes	923,000	1,697,000
(Gain) loss on derivative instruments	(73,000)	95,000
Compensation expense related to stock-based awards and employee stock purchase plan	2,988,000	2,747,000
Changes in operating assets and liabilities:
Accounts receivable	3,573,000	(3,197,000)
Inventories	(1,831,000)	778,000
Prepaid expenses and other assets	(84,000)	(257,000)
Other non-current assets	(387,000)	(442,000)
Accounts payable	278,000	467,000
Deferred revenue	796,000	(723,000)
Accrued expenses	(117,000)	3,493,000
Other long-term liabilities	982,000	(3,000)
Net cash provided by operating activities	16,973,000	9,411,000
Cash flows from investing activities:
Capital expenditures	(3,031,000)	(5,240,000)
Net cash paid for business acquired	(22,943,000)	0
Purchases of marketable securities	(35,221,000)	(13,106,000)
Maturities and sales of marketable securities	16,166,000	12,361,000
Net cash used in investing activities	(45,029,000)	(5,985,000)
Cash flows from financing activities:
Repayments of long-term debt	(772,000)	(98,000)
Borrowings from long-term debt	4,671,000	0
Proceeds from stock options exercised and employee stock purchase plan	2,360,000	784,000
Payment of employee restricted stock withholdings	(828,000)	(333,000)
Repayments of line of credit borrowings	0	(2,000,000)
Proceeds from line of credit borrowings	23,000,000	0
Payment of stock registration fee	(5,000)	0
Net cash provided by (used in) financing activities	28,426,000	(1,647,000)
Effect of exchange rate changes on cash and cash equivalents	(135,000)	(175,000)
Net increase in cash and cash equivalents	235,000	1,604,000
Cash and cash equivalents at beginning of period	8,978,000	7,017,000
Cash and cash equivalents at end of period	$ 9,213,000	$ 8,621,000