CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (9,022)	$ (796)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization of property and equipment	16,900	18,234
Amortization of intangible assets	7,872	9,135
Accretion of closure and post-closure obligations	1,227	1,182
Unrealized foreign currency gain	(852)	(315)
Deferred income taxes	(3,467)	(3,781)
Share-based compensation expense	1,948	1,928
Share-based payments of business development and integration expenses	120	163
Unrecognized tax benefits	13	12
Net gain on disposition of assets	(245)	(221)
Amortization of debt issuance costs	589	577
Amortization of debt discount	40	40
Change in fair value of minority interest investment		(3,509)
Changes in assets and liabilities:
Receivables	3,865	(680)
Income taxes receivable	6,514	1,276
Other assets	1,106	1,114
Accounts payable and accrued liabilities	(4,155)	(3,647)
Deferred revenue	3,917	2,214
Accrued salaries and benefits	(3,407)	(3,028)
Income taxes payable	(329)	(98)
Closure and post-closure obligations	(517)	(337)
Net cash provided by operating activities	22,117	19,463
Cash flows from investing activities:
Purchases of property and equipment	(16,180)	(9,614)
Proceeds from sale of property and equipment	438	1,623
Minority interest investment		(712)
Proceeds from sale of short-term investments	1,932
Purchases of restricted investments		(913)
Proceeds from sale of restricted investments		934
Net cash used in investing activities	(13,810)	(8,682)
Cash flows from financing activities:
Proceeds from short-term borrowings	1,959	3,227
Payments on short-term borrowings	(1,959)	(2,950)
Payments on long-term debt	(1,125)	(1,125)
Payment of equipment financing obligations	(1,218)	(1,461)
Repurchase of common stock	(12)	(465)
Net cash used in financing activities	(2,355)	(2,774)
Effect of foreign exchange rate changes on cash	712	708
Increase in Cash and cash equivalents and restricted cash	6,664	8,715
Cash and cash equivalents and restricted cash at beginning of period	69,054	75,104
Cash and cash equivalents and restricted cash at end of period	$ 75,718	$ 83,819