Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Operating Activities
Net income	$ 53,578	$ 40,012
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,893	10,920
Deferred income taxes		(589)
Stock-based compensation	3,806	4,021
(Gain) loss on disposal of property, plant and equipment	(189)	168
Excess tax benefits from stock compensation	(1,699)	(2,437)
Other non-cash adjustments	(287)	(269)
Changes in operating assets and liabilities:
Accounts receivable	1,580	(44,005)
Inventories	6,597	6,792
Prepaid expenses and other assets	(771)	(310)
Accounts payable	(6,759)	(9,904)
Accrued expenses and other liabilities	5,005	3,626
Income taxes receivable/payable	10,126	4,126
Net cash provided by operating activities	81,880	12,151
Investing Activities
Expenditures for property, plant and equipment	(8,534)	(18,279)
Proceeds from sales of property, plant and equipment	4,349	35
Purchase of acquired company, net of cash acquired		(32)
Net cash used in investing activities	(4,185)	(18,276)
Financing Activities
Borrowings under line of credit	242,700	199,000
Principal payments under line of credit	(249,700)	(150,500)
Repurchases of common stock	(55,185)	(52,081)
Financing costs	(485)
Proceeds from employee stock purchase and option plans	218	257
Excess tax benefits from stock compensation	1,699	2,437
Net cash used in financing activities	(60,753)	(887)
Net increase (decrease) in cash and cash equivalents	16,942	(7,012)
Cash and cash equivalents, beginning of period	5,995	9,544
Cash and cash equivalents, end of period	22,937	2,532
Supplemental Disclosure:
Cash paid for interest	849	390
Cash paid for income taxes, net	$ 19,435	$ 20,164