Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 151,803	$ 253,307
Accounts receivable, net (Note 5)	211,526	181,604
Inventory (Note 6)	265,334	230,691
Prepaid and other current assets	59,671	50,597
Investment in GreenFirst equity securities (Note 3)	0	38,510
Income tax receivable (Note 19)	1,196	21,411
Total current assets	689,530	776,120
Property, plant and equipment, net (Note 7)	1,151,268	1,146,162
Deferred tax assets (Note 19)	322,164	335,119
Intangible assets, net (Note 2)	24,423	31,432
Other assets	160,143	156,191
Total assets	2,347,528	2,445,024
Current liabilities
Accounts payable	163,962	169,456
Accrued and other current liabilities (Note 8)	164,369	136,124
Debt due within one year (Note 9)	14,617	37,680
Current environmental liabilities (Note 10)	10,732	11,303
Total current liabilities	353,680	354,563
Long-term debt (Note 9)	838,508	891,031
Non-current environmental liabilities (Note 10)	159,949	159,919
Pension and other postretirement benefits (Note 17)	119,571	170,317
Deferred tax liabilities (Note 19)	17,021	20,485
Other liabilities	29,486	34,366
Commitments and contingencies (Note 21)
Stockholders’ equity (Note 13)
Common stock, 140,000,000 shares authorized at $0.01 par value, 64,020,761 and 63,738,409 issued and outstanding, respectively	640	637
Additional paid-in capital	418,048	408,834
Retained earnings	474,423	489,342
Accumulated other comprehensive loss (Note 14)	(63,798)	(84,470)
Total stockholders’ equity	829,313	814,343
Total liabilities and stockholders’ equity	$ 2,347,528	$ 2,445,024