Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (58,334)	$ (81,847)	$ (105,254)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	123,768	125,846	126,443
Impairment charges	26,148	28,661	31,604
Inventory write-down	0	0	525
Loss on extinguishment of debt	0	748	842
Deferred income tax benefit	(11,713)	(31,403)	(8,976)
Non-cash compensation charge	10,116	11,036	7,338
Gain on disposals of assets	(3,882)	(1,606)	(825)
Provision (benefit) for loss on receivables, net of recoveries	(30)	(276)	51
Other, net	2,659	4,879	3,871
Changes in operating assets and liabilities:
Accounts receivable	(20,547)	13,326	(6,896)
Inventories	(87)	3,376	(4,463)
Accounts payable and accrued liabilities	8,473	(17,716)	12,674
Taxes payable	(75)	5,310	3,210
Other current assets and liabilities, net	(2,015)	(5,943)	(3,318)
Net cash flows provided by operating activities	74,481	54,391	56,826
Cash flows from investing activities:
Capital expenditures	(29,812)	(17,108)	(11,194)
Payments related to acquisitions, net of cash acquired	(16,434)	(171,337)	0
Proceeds from disposition of property, plant and equipment	5,906	5,844	1,908
Other, net	1,762	654	548
Net cash flows used in investing activities	(38,578)	(181,947)	(8,738)
Cash flows from financing activities:
Proceeds from issuance of common shares, net	0	0	64,734
Revolving credit borrowings	381,615	358,312	44,525
Revolving credit repayments	(385,071)	(217,339)	(84,462)
Term loan repayments	(34,942)	(26,609)	(40,781)
Debt issuance costs	(1,950)	(4,009)	(1,795)
Other, net	(4,283)	(832)	(293)
Net cash flows provided by (used in) financing activities	(44,631)	109,523	(18,072)
Effect of exchange rate changes on cash	(313)	(2,242)	846
Net change in cash and cash equivalents	(9,041)	(20,275)	30,862
Cash and cash equivalents, beginning of period	12,372	32,647	1,785
Cash and cash equivalents, end of period	3,331	12,372	32,647
Non-cash investing and financing items
Preferred dividends paid-in-kind	1,849	1,459	0
Common Shares
Non-cash investing and financing items
Value of shares issued as consideration for acquisitions	0	119,797	0
Preferred Shares
Non-cash investing and financing items
Value of shares issued as consideration for acquisitions	$ 0	$ 54,821	$ 0