Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Activities
Net income	$ 19,259	$ 13,864
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	6,268	6,747
Amortization of bond premiums	304	20
Provision for losses on accounts receivable, net of adjustments	102	(1)
Provision for excess and obsolete inventories	201	0
Share-based compensation	695	364
Excess tax benefits from stock options exercised and restricted stock awards vested	(385)	(33)
(Gain) loss on disposition of assets	(52)	(13)
Foreign currency transaction gain	43	7
Interest income on note receivable	(20)	0
Deferred income taxes	(1,966)	(875)
Write-off of note receivable	75	0
Changes in assets and liabilities:
Accounts receivable	(6,344)	(17,949)
Income tax receivable	3,942	5,801
Inventories	(1,718)	(4,194)
Prepaid expenses and other	(160)	(91)
Accounts payable	1,101	4,215
Deferred revenue	201	0
Accrued liabilities	6,194	11,714
Net cash provided by operating activities	27,740	19,576
Investing Activities
Capital expenditures	(1,949)	(8,091)
Proceeds from sale of property, plant and equipment	60	306
Investment in certificates of deposits	(958)	(4,274)
Maturities of certificates of deposits	1,440	0
Purchase of investments held to maturity	(9,969)	(5,624)
Maturities of investments	1,710	0
Proceeds from called investment	0	270
Principal payments from note receivable	40	15
Net cash used in investing activities	(9,626)	(17,398)
Financing Activities
Borrowings under revolving credit facility	2,321	27,108
Payments under revolving credit facility	(2,321)	(24,424)
Stock options exercised	767	69
Excess tax benefits from stock options exercised and restricted stock awards vested	385	33
Repurchase of stock	(3,010)	(1,895)
Net cash used in financing activities	(1,858)	891
Net increase (decrease) in cash and cash equivalents	16,256	3,069
Cash and cash equivalents, beginning of period	3,159	13
Cash and cash equivalents, end of period	$ 19,415	$ 3,082