Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
OPERATING ACTIVITIES:
Consolidated net (loss) income	$ (116,731)	$ 43,564
Adjustments to reconcile consolidated net income to net cash (used in) provided by operating activities:
Depreciation and amortization	40,439	42,212
Amortization of debt financing costs	2,608	2,608
Impairment of intangible assets	83,349	8,079
Non-cash stock compensation expense	11,453	9,844
Income from available-for-sale securities	0	(3,032)
Deferred income taxes, net	(24,512)	(2,341)
Loss on sale of available-for-sale securities	0	196
Other	481	(288)
Changes in operating assets and liabilities:
Trade accounts receivable	(45,893)	105,848
Inventories, net	(7,735)	(6,225)
Prepaid expenses and other current assets	8,176	2,078
Trade accounts payable	602	(13,465)
Accrued expenses and other liabilities	16,490	(30,051)
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	(31,273)	159,027
INVESTING ACTIVITIES:
Proceeds from disposal of assets	20	4,811
Payments for intangible assets	(50)	(200)
Purchases of property, plant and equipment	(35,862)	(50,072)
NET CASH USED IN INVESTING ACTIVITIES	(35,892)	(45,461)
FINANCING ACTIVITIES:
Proceeds from the exercise of stock options	254	6,897
Payment of contingent acquisition liabilities	(4,793)	0
Lease payments	(6)	0
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES	(4,545)	6,897
Effect of exchange rate changes on cash and cash equivalents	(560)	626
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(72,270)	121,089
Cash and cash equivalents, and restricted at beginning of period	369,889	204,034
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT END OF PERIOD	297,619	325,123
SUPPLEMENTAL DISCLOSURES:
Amount paid for interest	25,462	22,124
Amount paid for income taxes, net	9,260	43,901
Additional capital expenditures included in accounts payable	$ 12,010	$ 8,806