Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 12,328	$ 33,860	$ 50,535
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	12,465	11,178	13,091
Share-based compensation expense	7,592	5,854	4,725
Excess tax benefits from stock-based awards	(218)	(477)	(211)
Impairment of technology	1,000
Loss (gain) on disposal of assets	1	(13)	11
Deferred income tax provision (benefit)	9,654	3,104	(5,676)
Changes in operating assets and liabilities
Accounts receivable	(1,135)	8,746	(7,801)
Inventories	(4,684)	455	(2,522)
Income taxes receivable	2,569	(136)	(4,046)
Prepaid expenses and other assets	(1,469)	(165)	(2,294)
Accounts payable	3,928	(2,576)	4,367
Income taxes payable	(3,508)	877	1,254
Accrued compensation	(830)	(3,454)	5,632
Accrued commissions	(46)	(103)	410
Other current liabilities	(100)	913	171
Deferred income on shipments to distributors	(4,903)	(7,975)	15,241
Net cash provided by operating activities	32,644	50,088	72,887
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of PhaseLink's net assets, net of cash acquired	(17,370)
Purchases of property, plant and equipment	(9,022)	(7,277)	(9,760)
Purchases of investments	(55,819)	(77,510)	(34,589)
Proceeds from sale and maturities of investments	60,108	40,585	1,500
Change in restricted cash	(291)
Net cash used in investing activities	(22,394)	(44,202)	(42,849)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayments of debt	(282)	(2,857)	(8,571)
Proceeds from the issuance of common stock	3,642	12,040	6,861
Repurchases of common stock	(34,551)	(20,253)	(16,053)
Payment of cash dividends	(12,072)	(9,358)	(8,646)
Purchase of stock for withholding taxes on vested restricted stock	(534)	(63)
Excess tax benefits from stock-based awards	218	477	211
Net cash used in financing activities	(43,579)	(20,014)	(26,198)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(33,329)	(14,128)	3,840
CASH AND CASH EQUIVALENTS - Beginning of period	60,610	74,738	70,898
CASH AND CASH EQUIVALENTS - End of period	27,281	60,610	74,738
Cash paid during the year for:
Interest	2	19	223
Income taxes	$ 7,060	$ 11,164	$ 33,125