CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income (loss)	$ (95,695)	$ (100,639)	$ 93,221
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	35,312	40,974	31,857
Stock-based compensation expense	13,459	14,270	12,217
Impairment and other non-cash charges	98,602	60,968	0
Loss (gain) on sale of equipment	(6,198)	(168)	(103)
Deferred income taxes	(4,091)	17,231	(3,400)
Changes in operating assets and liabilities:
Trade receivables, net	(11,855)	26,112	106,544
Inventories, net	49,926	37,642	7,873
Prepaids and other assets	(15,084)	10,107	9,816
Excess tax benefits of stock options and awards	0	0	(135)
Accounts payable and accrued expenses	(18,755)	1,765	(11,368)
Other, net	(118)	(269)	0
Net cash provided by operating activities	45,503	107,993	246,522
Investing activities
Purchase of property, plant and equipment	(32,061)	(27,622)	(25,763)
Proceeds from sale of equipment	16,888	3,170	357
Acquisition of business, net of cash acquired	0	(20,440)	(132,443)
Net cash used in investing activities	(15,173)	(44,892)	(157,849)
Financing activities
Proceeds from exercise of stock options	1,616	560	2,206
Excess tax benefits of stock options and awards	0	0	135
ABL Credit Facility issuance costs	(815)	0	0
Repurchase of common shares	(100,000)	0	(24,234)
Net cash used in financing activities	(99,199)	560	(21,893)
Effect of exchange rate changes on cash activities	(6,211)	6,022	(24,619)
Increase (decrease) in cash and cash equivalents	(75,080)	69,683	42,161
Cash and cash equivalents at beginning of year	493,180	423,497	381,336
Cash and cash equivalents at end of year	$ 418,100	$ 493,180	$ 423,497