CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 24,575	$ 285
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,968	7,627
Amortization of intangibles	3,684	1,479
Loss (gain) on sale of property and equipment	17	(1)
Gain on sale of assets held for sale	(497)	0
Stock-based compensation expense	7,964	6,673
Amortization of premium on marketable securities	251	567
Non-cash interest income from SemiSouth note	0	(780)
Deferred income taxes	(2,388)	4,834
Reduction in accounts receivable allowances	(153)	(14)
Excess tax benefit from stock options exercised	0	(474)
Tax benefit associated with employee stock plans	0	1,531
Change in operating assets and liabilities:
Accounts receivable	(8,294)	(5,336)
Inventories	1,421	14,119
Prepaid expenses and other assets	5,198	2,834
Accounts payable	3,457	3,795
Taxes payable and accrued liabilities	(480)	8,784
Deferred income on sales to distributors	3,484	3,387
Net cash provided by operating activities	46,207	49,310
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(6,892)	(8,754)
Proceeds from sale of property and equipment	36	2
Proceeds from sale of assets held for sale	959	0
Acquisition	0	(113,360)
Increase in financing lease receivable	0	(383)
Collections of financing lease receivable	0	299
Loan to SemiSouth	0	(18,000)
Purchases of marketable securities	(45,223)	0
Proceeds from maturities of marketable securities	16,850	12,468
Net cash used in investing activities	(34,270)	(127,728)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	14,749	14,321
Payments of dividends to stockholders	(4,654)	(2,853)
Excess tax benefit from stock options exercised	0	474
Net cash provided by financing activities	10,095	11,942
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	22,032	(66,476)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	63,394	139,836
CASH AND CASH EQUIVALENTS AT END OF PERIOD	85,426	73,360
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,447	1,578
Receipt of SemiSouth purchase option	0	6,216
Acquisition net asset value adjustment (Note 14)	0	2,358
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash (received) paid for income taxes, net of refunds	$ (3,133)	$ 2,076