Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 26,128	$ 29,840
Restricted cash	261	6,691
Trade accounts receivable, net of allowance for doubtful accounts of $7,847 in 2015 and $2,485 in 2014	172,977	114,284
Inventories	120,054	106,546
Prepaid expenses and other current assets	18,934	18,430
Total current assets	338,354	275,791
Property, plant, and equipment:
Land and building	80,583	78,929
Machinery and equipment	1,357,225	1,348,286
Automobiles and trucks	35,070	36,341
Chemical plants	186,790	182,951
Construction in progress	31,715	11,918
Total property, plant, and equipment	1,691,383	1,658,425
Less accumulated depreciation	(796,078)	(712,974)
Net property, plant, and equipment	895,305	945,451
Other assets:
Goodwill	6,636	6,636
Patents, trademarks, and other intangible assets, net of accumulated amortization of $44,695 in 2015 and $39,754 in 2014	47,710	67,713
Deferred tax assets	10	28
Other assets	20,599	19,921
Total other assets	74,955	94,298
Total assets	1,308,614	1,315,540
Current liabilities:
Trade accounts payable	84,876	45,889
Unearned income	18,971	13,879
Accrued liabilities	69,390	55,666
Decommissioning and other asset retirement obligations, current	477	1,451
Total current liabilities	173,714	116,885
Long-term debt, net	629,855	623,730
Deferred income taxes	4,404	7,296
Decommissioning and other asset retirement obligations, net	57,925	54,027
CCLP Series A Preferred Units	61,436	77,062
Warranty Liability	13,202	18,503
Other liabilities	15,517	17,571
Total long-term and other liabilities	782,339	798,189
Equity:
Common stock, par value $.01 per share; 100,000,000 shares authorized; 83,013,971 shares issued at December 31, 2015, and 82,322,876 shares issued at December 31, 2014	1,185	1,175
Additional paid-in capital	425,648	419,236
Treasury stock, at cost; 2,766,958 shares held at December 31, 2015, and 2,672,930 shares held at December 31, 2014	(18,651)	(18,316)
Accumulated other comprehensive income (loss)	(43,767)	(51,285)
Retained earnings	(156,335)	(117,287)
Total TETRA stockholders' equity	208,080	233,523
Noncontrolling interest	144,481	166,943
Total equity	352,561	400,466
Total liabilities and equity	$ 1,308,614	$ 1,315,540