CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 7,461	$ 9,854
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	3,732	3,682
Amortization of intangibles	189	243
Gain on sale of property and equipment	(1)	0
Stock-based compensation expense	3,031	2,504
Amortization of premium on marketable securities	309	439
Non-cash interest income from SemiSouth note	(157)	0
Deferred income taxes	(327)	399
Provision for accounts receivable allowances	0	22
Excess tax benefit from stock options exercised	(198)	(398)
Tax benefit associated with employee stock plans	782	783
Change in operating assets and liabilities:
Accounts receivable	(7,300)	(7,622)
Inventories	9,161	(964)
Prepaid expenses and other assets	1,306	1,435
Accounts payable	1,485	(2,908)
Taxes payable and accrued liabilities	604	(525)
Deferred income on sales to distributors	1,490	(1,269)
Net cash provided by operating activities	21,567	5,675
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(7,471)	(7,248)
Proceeds from sale of property and equipment	2	0
Acquisition	0	(6,901)
Increase in financing lease receivables	(383)	(5,642)
Collections of financing lease receivable	299	102
Loan to SemiSouth	(18,000)	0
Purchases of marketable securities	0	(11,508)
Proceeds from maturities of marketable securities	6,065	1,300
Net cash used in investing activities	(19,488)	(29,897)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	6,457	7,288
Payments of dividends to stockholders	(1,415)	(1,437)
Excess tax benefit from stock options exercised	198	398
Net cash provided by financing activities	5,240	6,249
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	7,319	(17,973)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	139,836	155,667
CASH AND CASH EQUIVALENTS AT END OF PERIOD	147,155	137,694
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	965	1,917
Receipt of SemiSouth purchase option	6,216	0
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net of refunds	$ 630	$ 118