Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 5,588	$ 18,068
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	23,070	22,755
Stock-based compensation expense	6,874	4,848
Provision for deferred income taxes	(1,514)	243
Net provision for doubtful accounts	789	1,229
Gain on sale of assets	(5,128)	(371)
Amortization of original issue discount and debt issuance costs	2,973	2,643
Change in assets and liabilities:
(Increase) decrease in receivables	6,583	(1,185)
(Increase) decrease in inventories	3,868	(21,459)
Increase in other assets	(5,058)	(3,417)
Increase in accounts payable	6,207	6,659
Decrease in accrued liabilities and other	(10,012)	(9,326)
Net cash provided by operating activities	34,240	20,687
Cash flows from investing activities:
Capital expenditures	(23,866)	(24,458)
Proceeds from sale of property, plant and equipment	5,708	920
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	(18,158)	(37,761)
Cash flows from financing activities:
Borrowings on lines of credit	135,952	203,716
Payments on lines of credit	(141,317)	(171,796)
Debt issuance costs	(917)	(11)
Proceeds from employee stock plans	1,090	3,700
Purchases of treasury stock	(17,365)	(3,074)
Other financing activities	2,758	2,515
Net cash provided by (used in) financing activities	(19,799)	35,050
Effect of exchange rate changes on cash	(125)	(2,926)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(3,842)	15,050
Cash, cash equivalents, and restricted cash at beginning of period	64,266	65,460
Cash, cash equivalents, and restricted cash at end of period	$ 60,424	$ 80,510