Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 5,818	$ 10,280
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,853	6,562
Share-based compensation expense	3,671	3,313
Excess tax benefits from stock-based awards	(584)	(180)
Deferred income tax provision	(3,473)	(2,953)
Changes in operating assets and liabilities
Accounts receivable	(5,255)	(7,852)
Inventories	1,178	(930)
Prepaid taxes	2,502	1,737
Prepaid expenses and other assets	164	(539)
Accounts payable	2,087	(7,452)
Income taxes payable	1,574	533
Accrued liabilities and other long-term liabilities	(926)	1,019
Deferred income on shipments to distributors	5,997	6,212
Net cash provided by operating activities	19,606	9,750
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property, plant and equipment	(3,855)	(3,853)
Purchases of intangible assets	0	(57)
Purchases of investments	(29,602)	(35,785)
Proceeds from sale and maturities of investments	31,369	47,500
Change in restricted cash	20	165
Net cash (used in) provided by investing activities	(2,068)	7,970
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from the issuance of common stock	4,615	2,355
Repurchases of common stock	(5,815)	(4,690)
Payment of cash dividends	(5,638)	(2,482)
Purchase of stock for withholding taxes on vested restricted stock	(616)	(327)
Excess tax benefits from stock-based awards	584	180
Net cash used in financing activities	(6,870)	(4,964)
NET INCREASE IN CASH AND CASH EQUIVALENTS	10,668	12,756
CASH AND CASH EQUIVALENTS - Beginning of period	23,787	27,281
CASH AND CASH EQUIVALENTS - End of period	$ 34,455	$ 40,037