CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 7,565	$ 10,742
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization	40,662	44,509
Provision for doubtful accounts	2,299	3,397
Amortization of debt discount and debt issuance costs	337	260
Stock-based compensation	3,511	2,721
Deferred income taxes	(3,236)	(3,204)
(Gain) loss on equity investments	(1,793)	1,412
Loss on disposition of long-lived assets	861	64
Unrealized (gain) loss on foreign currency	(81)	780
Changes in operating assets and liabilities, excluding the effects of acquisitions and dispositions:
Accounts receivable	1,226	(14,475)
Customer receivable	(21,586)
Materials and supplies, prepayments, and other current assets	(73)	(7,313)
Prepaid income taxes		399
Accounts payable and accrued liabilities, advance payments and deposits and other current liabilities	(1,745)	2,497
Accrued taxes	(1,360)	(1,838)
Other assets	782	993
Other liabilities	91	(569)
Net cash provided by operating activities	27,460	40,375
Cash flows from investing activities:
Capital expenditures	(35,424)	(30,597)
Reimbursable capital expenditures	(6,508)	(1,368)
Receipt of capital government grants	3,292
Divestiture of businesses, net of transferred cash of $0.9 million	18,597
Purchase of intangible assets; including deposits		(20,000)
Purchases of strategic investments	(5,242)	(2,768)
Net cash used in investing activities	(25,285)	(54,733)
Cash flows from financing activities:
Dividends paid on common stock	(5,411)	(5,443)
Distributions to non-controlling interests	(4,488)	(5,541)
Repayment of customer receivable credit facility	(384)
Payment of debt issuance costs		(1,059)
Principal repayments of term loan	(1,883)	(1,876)
Purchases of common stock - stock-based compensation	(1,713)	(1,733)
Purchases of common stock - share repurchase plan	(2,219)	(2,449)
Repurchases of non-controlling interests	(12,699)	(3,911)
Proceeds from customer receivable credit facility	17,582
Net cash used in financing activities	(11,215)	(22,012)
Effect of foreign currency exchange rates on cash and cash equivalents		(118)
Net change in cash, cash equivalents, and restricted cash	(9,040)	(36,488)
Total cash, cash equivalents, and restricted cash, beginning of period	104,997	162,358
Total cash, cash equivalents, and restricted cash, end of period	95,957	125,870
Noncash investing activity:
Purchases of property, plant and equipment included in accounts payable and accrued expenses	$ 11,990	$ 7,715