Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net income	$ 9,687	$ 11,052
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	9,320	10,621
Amortization	2,953	3,286
Deferred income taxes	1,041	633
Asset impairments	0	121
Gain on the sale of property, plant and equipment	(197)	(93)
Stock-based compensation expense	2,160	2,113
Excess tax benefit from stock-based compensation	0	(149)
Changes in operating assets and liabilities, net of effects from business acquisitions:
Accounts receivable	59,685	65,382
Inventories	(22,512)	22,756
Prepaid expenses and other assets	(5,329)	(5,403)
Accounts payable	16,225	(31,940)
Accrued liabilities	5,256	(1,499)
Income taxes	(384)	201
Net cash provided by operations	77,905	77,081
Cash flows from investing activities:
Additions to property, plant and equipment	(7,012)	(7,700)
Proceeds from the sale of property, plant and equipment	217	130
Additions to purchased software	(566)	(137)
Other	(108)	62
Net cash used in investing activities	(7,469)	(7,645)
Cash flows from financing activities:
Proceeds from stock options exercised	5,141	763
Shares withheld for taxes	(358)	(568)
Excess tax benefits from stock-based compensation	0	149
Principal payments on long-term debt and capital lease obligations	(3,082)	(3,078)
Share repurchases	(1,000)	(14,205)
Debt issuance costs	(434)	0
Net cash provided by (used in) financing activities	267	(16,939)
Effect of exchange rate changes	341	675
Net increase in cash and cash equivalents	71,044	53,172
Cash and cash equivalents at beginning of year	681,433	465,995
Cash and cash equivalents at end of period	$ 752,477	$ 519,167