Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 75,165	$ 17,704
Restricted cash	59	64
Trade accounts receivable, net of allowances	108,222	175,918
Inventories	113,020	136,510
Disposal Group, Including Discontinued Operation, Assets, Current	0	0
Prepaid expenses and other current assets	21,176	21,158
Total current assets	317,642	351,354
Property, plant, and equipment:
Land and building	39,534	60,586
Machinery and equipment	1,341,905	1,335,157
Automobiles and trucks	26,581	31,681
Chemical plants	60,195	57,692
Construction in progress	10,819	34,393
Total property, plant, and equipment	1,479,034	1,519,509
Less accumulated depreciation	(804,466)	(760,872)
Net property, plant, and equipment	674,568	758,637
Other assets:
Patents, trademarks and other intangible assets, net of accumulated amortization	68,350	74,199
Deferred tax assets, net	24	24
Operating lease right-of-use assets	78,867	68,131
Other assets	22,089	19,577
Total other assets	169,330	161,931
Total assets	1,161,540	1,271,922
Current liabilities:
Trade accounts payable	42,406	88,917
Unearned income	7,310	9,831
Accrued liabilities	80,500	87,877
Disposal Group, Including Discontinued Operation, Liabilities, Current	1,852	2,098
Total current liabilities	132,068	188,723
Long-term debt, net	843,216	842,871
Deferred income taxes	3,421	2,988
Decommissioning and other asset retirement obligations, net	12,973	12,762
Warranty Liability	123	449
Operating lease liabilities	64,200	53,919
Other liabilities	10,364	7,384
Total long-term liabilities	934,297	920,373
Equity:
Common stock, par value $0.01 per share	1,289	1,283
Additional paid-in capital	471,146	466,959
Treasury stock, at cost	(19,484)	(19,164)
Accumulated other comprehensive income (loss)	(54,634)	(52,183)
Retained earnings	(398,630)	(362,522)
Total TETRA stockholders' equity	(313)	34,373
Noncontrolling interests	95,488	128,453
Total equity	95,175	162,826
Total liabilities and equity	1,161,540	1,271,922
Trade accounts receivable, allowances for doubtful accounts	7,742	5,262
Patents, trademarks, and other intangible assets, accumulated amortization	$ 93,976	$ 88,422
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	128,930,704	128,304,354
Treasury stock, shares held	2,953,976	2,823,191