CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net loss	$ (67,236)	$ (74,835)
Adjustments to reconcile net loss to cash from operating activities
Depreciation and amortization	70,637	84,160
Equity-based compensation expense	8,238	8,176
Amortization of deferred financing costs	274	0
Deferred tax provision	3,887	0
Provision for (recovery of) bad debts	(27)	68
(Gain) loss on disposal of assets	984	(1,790)
Changes in fair value of investments	(1,935)	(1,295)
Unrealized gain on derivative instruments	(349)	(442)
Loss on asset impairments	4,268	0
Other	(566)	0
Changes in operating assets and liabilities
Accounts receivable	9,872	(37,252)
Inventories	(14,191)	(3,470)
Other current assets	2,537	2,237
Other assets	179	204
Accounts payable and accrued liabilities	(7,844)	(10,249)
Deferred revenue	110	(346)
Other non-current liabilities	(353)	(560)
Net cash provided by (used in) operating activities	8,485	(35,394)
Cash flows from investing activities
Purchases of property, plant and equipment and intangibles	(26,979)	(14,557)
Proceeds from sale of assets	353	4,419
Proceeds from sale of investments	46,739	67,934
Purchase of investments	(20,304)	(67,011)
Net cash used in investing activities	(191)	(9,215)
Cash flows from financing activities
Repayments of borrowings	(5,110)	(4,289)
Treasury shares withheld for taxes	(1,874)	(1,501)
Proceeds from the issuance of ESPP shares	1,752	1,315
Deferred financing costs	(184)	(161)
Net cash used in financing activities	(5,416)	(4,636)
Effect of exchange rate changes on cash	2,684	2,357
Net increase (decrease) in cash, cash equivalents and restricted cash	5,562	(46,888)
Cash, cash equivalents and restricted cash at beginning of period	186,212	213,015
Cash, cash equivalents and restricted cash at end of period	$ 191,774	$ 166,127