CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
OPERATING ACTIVITIES:
Net loss			$ (17,000)	$ (45,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization expense	$ 55,000	$ 56,000	112,000	114,000
Amortization of deferred debt financing costs			2,000	2,000
Net gain on sale of business and investments	0	0	0	(9,000)
Impairment charges	0	0	0	19,000
Stock-based compensation expense	9,000	6,000	18,000	14,000
Provision for expected credit losses			0	1,000
Equity in net income from unconsolidated investments	0	0	(1,000)	(1,000)
Deferred income taxes			(9,000)	(9,000)
Dividends from unconsolidated investments			4,000	3,000
Other, net			(2,000)	3,000
Changes in working capital			47,000	62,000
Changes in noncurrent assets and liabilities, net			3,000	1,000
Net cash provided by operating activities			157,000	155,000
INVESTING ACTIVITIES:
Purchase of property, plant and equipment			(84,000)	(79,000)
Proceeds from asset sales			0	3,000
Investment in equity affiliates			(4,000)	(10,000)
Other, net			(1,000)	(8,000)
Net cash used in investing activities			(89,000)	(94,000)
FINANCING ACTIVITIES:
Proceeds from Other Debt			0	9,000
Proceeds from borrowings on revolving credit facility			179,000	256,000
Payments on long-term debt			(9,000)	(9,000)
Payments on revolving credit facility			(183,000)	(237,000)
Payments on project debt			(5,000)	(5,000)
Cash dividends paid to stockholders			(24,000)	(68,000)
Proceeds from related party note			0	9,000
Payments of insurance premium financing			(19,000)	(16,000)
Other, net			(7,000)	(5,000)
Net cash used in financing activities			(68,000)	(66,000)
Effect of exchange rate changes on cash, cash equivalents and restricted cash			0	(1,000)
Net decrease in cash, cash equivalents and restricted cash			0	(6,000)
Cash, cash equivalents and restricted cash at beginning of period			72,000	63,000
Cash, cash equivalents and restricted cash at end of period	72,000	57,000	72,000	57,000
Cash, cash equivalents and restricted cash at end of period	54,000	39,000	54,000	39,000
Restricted funds held in trust	8,000	10,000	8,000	10,000
Restricted funds held in trust	$ 10,000	$ 8,000	$ 10,000	$ 8,000