CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net income	$ 5,623	$ 15,901
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income taxes	819	5,608
Gain on extinguishment of debt	(1,134)
Depreciation and amortization of property, plant and equipment	17,114	17,439
Stock-based compensation	1,393	719
Other	3,929	1,223
Cash provided (used) by changes in assets and liabilities:
Accounts receivable	(11,408)	15,418
Inventories	6,165	1,251
Prepaid insurance	4,078	5,158
Supplies, prepaid items and other	(116)	(4,455)
Accounts payable	(7,911)	(4,861)
Accrued interest	7,867	10,905
Other assets and other liabilities	(2,312)	(5,059)
Net cash provided by operating activities	24,107	59,247
Cash flows from investing activities
Expenditures for property, plant and equipment	(18,287)	(18,437)
Proceeds from short-term investments	100,878	88,707
Purchases of short-term investments	(34,689)	(133,660)
Other investing activities		11
Net cash provided (used) by investing activities	47,902	(63,379)
Cash flows from financing activities
Repurchases of 6.25% Senior Secured Notes	(31,316)
Payments on other long-term debt	(1,443)	(2,180)
Payments on short-term financing	(4,379)	(5,967)
Acquisition of treasury stock, net	(7,163)
Payments of debt-related costs	(217)
Other financing activities		(2,541)
Net cash used by financing activities	(44,518)	(10,688)
Net increase (decrease) in cash and cash equivalents	27,491	(14,820)
Cash, cash equivalents and restricted cash at beginning of period	101,032	63,769
Cash, cash equivalents and restricted cash at end of period	$ 128,523	$ 48,949