CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating activities
Net loss	$ (4,369)	$ (10,421)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	16,851	17,242
Stock-based compensation expense	8,083	7,585
Restructuring and other charges	314	0
Gain on sale of assets	(1,203)	(5,099)
Deferred income taxes	164	578
Changes in operating assets and liabilities:
Trade receivables, net	(16,716)	7,007
Inventories, net	(1,002)	22,731
Prepaids and other assets	5,860	(3,117)
Accounts payable and accrued expenses	2,731	(13,374)
Other, net	(63)	334
Net cash provided by operating activities	10,650	23,466
Investing activities
Purchase of property, plant and equipment	(4,598)	(19,605)
Proceeds from sale of equipment	1,565	10,517
Net cash used in investing activities	(3,033)	(9,088)
Financing activities
Repurchase of common shares	(1,996)	(9,830)
ABL Credit Facility issuance costs		(815)
Proceeds from exercise of stock options	0	642
Net cash used in financing activities	(1,996)	(10,003)
Effect of exchange rate changes on cash activities	(595)	(4,133)
Increase in cash and cash equivalents	5,026	242
Cash and cash equivalents at beginning of period	418,100	493,180
Cash and cash equivalents at end of period	$ 423,126	$ 493,422