CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 57,266	$ (34,404)	$ 34,291
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	16,088	15,256	15,372
Amortization of intangibles	7,404	5,164	943
Charge related to SemiSouth (Note 12)	0	58,945	0
Gain on disposal of property and equipment	(131)	(1)	(41)
Gain on sale of asset held for sale	(497)	0	0
Stock-based compensation expense	16,485	14,224	8,969
Amortization of premium on marketable securities	789	850	1,627
Non-cash interest income from SemiSouth note	0	(1,445)	0
Deferred income taxes	(2,781)	2,017	1,577
Reduction in accounts receivable allowances	(127)	(24)	(61)
Excess tax benefit from stock options exercised	(734)	(704)	(796)
Tax benefit associated with employee stock plans	1,284	1,303	2,201
Change in operating assets and liabilities:
Accounts receivable	(4,936)	5,313	(3,621)
Inventories	2,375	18,026	10,037
Prepaid expenses and other assets	(1,523)	(11,008)	1,619
Accounts payable	2,467	2,071	(1,564)
Taxes payable and accrued liabilities	1,065	(26,029)	2,977
Deferred income on sales to distributors	4,177	2,276	(4,338)
Net cash provided by operating activities	98,671	51,830	69,192
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(13,960)	(16,358)	(23,223)
Proceeds from sale of property and equipment	36	2	2,249
Proceeds from Sale of Assets Held for Sale	959	0	0
Other assets	0	0	(1,277)
Acquisition (Note 11)	0	(115,720)	(6,914)
Payment of guarantee of SemiSouth debt (Note 12)	0	(15,200)	0
Increase in financing lease receivables	0	(420)	(8,116)
Collections of financing lease receivables and other receivables	433	527	425
Loans to SemiSouth (Note 12)	0	(18,000)	(3,000)
Collection of loan to SemiSouth	0	0	3,000
Purchases of marketable securities	109,482	0	42,176
Proceeds from sales and maturities of marketable securities	31,350	40,463	26,725
Net cash used in investing activities	(90,664)	(124,706)	(52,307)
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	30,239	21,952	22,210
Repurchase of common stock	0	(20,467)	(50,000)
Payments of dividends to stockholders	(9,446)	(5,755)	(5,722)
Excess tax benefit from stock options exercised	734	704	796
Net cash provided by (used in) financing activities	21,527	(3,566)	(32,716)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	29,534	(76,442)	(15,831)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	63,394	139,836	155,667
CASH AND CASH EQUIVALENTS AT END OF PERIOD	92,928	63,394	139,836
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,862	1,008	3,497
Unpaid financing lease equipment	0	0	321
Fair value of SemiSouth purchase option (Note 12)	0	6,216	0
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid (refund) for income taxes, net of refunds (Note 8)	$ (4,137)	$ 46,689	$ 1,233