Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net loss	$ (429,667)	$ (24,388)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization expense	51,055	63,434
Impairments of goodwill	406,056	0
Impairments of inventories	25,230	0
Impairments of fixed assets	8,190	0
Stock-based compensation expense	3,257	8,590
Amortization of debt discount and deferred financing costs	4,067	3,894
Deferred income tax benefit	(48,738)	(3,495)
Gain on extinguishment of 1.50% convertible senior notes	(4,779)	0
Gain on disposals of assets	(1,489)	(1,245)
Other, net	3,177	141
Changes in operating assets and liabilities:
Accounts receivable	56,062	19,884
Inventories	(4,320)	(534)
Accounts payable and accrued liabilities	(34,227)	1,200
Income taxes payable	(635)	943
Other operating assets and liabilities, net	10,892	(2,421)
Net cash flows provided by operating activities	44,131	66,003
Cash flows from investing activities:
Capital expenditures	(8,915)	(31,577)
Proceeds from disposition of property, plant and equipment	5,418	2,151
Other, net	(301)	(1,459)
Net cash flows used in investing activities	(3,798)	(30,885)
Cash flows from financing activities:
Revolving credit facility borrowings	72,173	119,252
Revolving credit facility repayments	(53,104)	(156,208)
Purchases of 1.50% convertible senior notes	(10,595)	0
Other debt and finance lease repayments, net	(165)	(301)
Payment of financing costs	(651)	(8)
Shares added to treasury stock as a result of net share settlements due to vesting of stock awards	(2,667)	(3,622)
Purchase of treasury stock	0	(757)
Net cash flows provided by (used in) financing activities	4,991	(41,644)
Effect of exchange rate changes on cash and cash equivalents	2	(384)
Net change in cash and cash equivalents	45,326	(6,910)
Cash and cash equivalents, beginning of period	8,493	19,316
Cash and cash equivalents, end of period	53,819	12,406
Cash paid for:
Interest	3,486	5,285
Income taxes, net of refunds	$ 2,888	$ 2,002