Consolidated Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities:
Net income	$ 39,314	$ 33,002
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	15,323	15,931
Deferred income tax benefit	(4,765)	(6,309)
Stock compensation	2,983	2,225
Defined benefit plan expense	105	28
Provision of doubtful accounts	252	(330)
Gain on revaluation of financial derivatives	(150)	(217)
Gain from equity investment		(785)
(Gain) loss on sale of property and equipment	(41)	28
Changes in operating assets and liabilities:
Accounts receivable	(16,711)	(17,456)
Inventory	(4,433)	5,024
Prepaid expenses and other assets	(6,674)	(6,959)
Accounts payable	13,148	(1,312)
Accrued liabilities	1,421	1,496
Net cash provided by operating activities	39,772	24,366
Investing Activities:
Acquisition and investment in subsidiary, net of cash acquired	(47)	(31,739)
Proceeds from the sale of property and equipment	225	44
Purchases of property and equipment	(23,029)	(15,489)
Net cash used in investing activities	(22,851)	(47,184)
Financing Activities:
Borrowing of debt		13,455
Repayments of debt	(2,801)	(12,470)
Excess tax benefit from equity awards	1,462	4,155
Cash paid for the cancellation of restricted stock	(467)
Proceeds from the exercise of Common Stock options	4,122	3,406
Net cash provided by financing activities	2,316	8,546
Foreign currency effect	(3,294)	2,541
Net increase (decrease) in cash and cash equivalents	15,943	(11,731)
Cash and cash equivalents at beginning of period	85,700	54,885
Cash and cash equivalents at end of period	101,643	43,154
Supplemental disclosure of cash flow information:
Cash paid for taxes	19,384	9,889
Cash paid for interest	890	1,308
Supplemental disclosure of non-cash transactions:
Common Stock issued to Board of Directors and employees	$ 1,389	$ 1,330