Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 4,147	$ 21,712
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	34,891	34,346
Stock-based compensation expense	9,375	8,497
Provision for deferred income taxes	(787)	(2,149)
Net provision for doubtful accounts	1,044	2,708
Gain on sale of assets	(5,779)	(552)
Amortization of original issue discount and debt issuance costs	4,589	4,075
Change in assets and liabilities:
(Increase) decrease in receivables	17,065	(16,531)
(Increase) decrease in inventories	11,873	(34,829)
Increase in other assets	(3,621)	(1,476)
Increase (decrease) in accounts payable	(11,806)	7,106
Decrease in accrued liabilities and other	(7,805)	(2,791)
Net cash provided by operating activities	53,186	20,116
Cash flows from investing activities:
Capital expenditures	(35,803)	(32,814)
Proceeds from sale of property, plant and equipment	7,116	1,477
Refund of proceeds from sale of a business	0	(13,974)
Business acquisitions, net of cash acquired	0	(249)
Net cash used in investing activities	(28,687)	(45,560)
Cash flows from financing activities:
Borrowings on lines of credit	237,093	275,801
Payments on lines of credit	(242,263)	(254,116)
Debt issuance costs	(1,214)	(149)
Proceeds from employee stock plans	1,236	3,813
Purchases of treasury stock	(21,678)	(3,811)
Other financing activities	1,336	2,140
Net cash provided by (used in) financing activities	(25,490)	23,678
Effect of exchange rate changes on cash	(1,526)	(3,798)
Net decrease in cash, cash equivalents, and restricted cash	(2,517)	(5,564)
Cash, cash equivalents, and restricted cash at beginning of period	64,266	65,460
Cash, cash equivalents, and restricted cash at end of period	$ 61,749	$ 59,896