Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Allowances for Doubtful Accounts Table

	Year Ended December 31,
	2020		2019		2018
	(In Thousands)
At beginning of period	$	1,912	$	1,354	$	368
Activity in the period:
Provision for doubtful accounts	5,672		2,580		1,152
Account (chargeoffs) recoveries	(760)		(2,022)		(166)
At end of period	$	6,824	$	1,912	$	1,354

Inventory Disclosure

Inventories are stated at the lower of cost or net realizable value. Except for work in progress inventory, cost is determined using the weighted average method. The cost of work in progress is determined using the specific identification method. INVENTORIES

    Components of inventories, net of reserve, are as follows:

	December 31,
	2020		2019
	(In Thousands)
Finished goods	$	68,121	$	70,135
Raw materials	2,910		4,125
Parts and supplies	4,001		4,979
Work in progress	1,626		1,234
Total inventories	$	76,658	$	80,473

Finished goods inventories include newly manufactured clear brine fluids as well as used brines that are repurchased from certain customers for recycling.

Property, Plant, and Equipment Table

Buildings	15 – 40 years
Machinery and equipment	2 – 20 years
Automobiles and trucks	3 – 4 years
Chemical plants	15 – 30 years