Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Summary of Significant Accounting Policies

Schedule of supplemental cash flow information (in thousands)

	Years Ended December 31,
	2020		2019		2018
Cash paid during the year for:
Interest	$	152	$	150	$	179
Income taxes	$	975	$	445	$	331

Schedule of the entity's financial liabilities measured at fair value on a recurring basis (in thousands)

			Significant Other
			Observable Inputs
			(Level 2)
	December 31,		December 31,
	2019		2019		Valuation Technique
Foreign exchange hedges	$	(1)	$	(1)	Cash flows approach

Schedule of additions and write-offs to the Company's allowance for doubtful accounts (in thousands)

	2020		2019
Beginning balance	$	361	$	430
Additions		60		102
Write-offs		(23)		(171)
Ending balance	$	398	$	361

Schedule of inventories, net

	December 31,		December 31,
	2020		2019
Lime and limestone inventories:
Raw materials	$	4,279	$	4,546
Finished goods		2,866		1,954
		7,145		6,500
Service parts inventories		8,065		6,888
	$	15,210	$	13,388

Schedule of estimated useful lives of property, plant and equipment (in thousands)

Buildings and building and leasehold improvements	3	-	25	years
Machinery and equipment	2	-	30	years
Furniture and fixtures	3	-	10	years
Automotive equipment	3	-	10	years

Schedule of accrued expenses (in thousands)

	December 31,
	2020		2019
Personnel related expenses	$	2,340	$	1,925
Income taxes		990		—
Other taxes		985		914
Other		1,494		896
	$	5,809	$	3,735

Schedule of computation of basic and diluted income per common share

	Years Ended December 31,
	2020		2019		2018
Net income for basic and diluted income per common share	$	28,223	$	26,056	$	19,685
Weighted-average shares for basic income per common share		5,629,425		5,612,048		5,595,384
Effect of dilutive securities:
Employee and director stock options(1)		10,438		9,090		6,993
Adjusted weighted-average shares and assumed exercises for diluted income per common share		5,639,863		5,621,138		5,602,377
Basic net income per common share	$	5.01	$	4.64	$	3.52
Diluted net income per common share	$	5.00	$	4.64	$	3.51

(1) Excludes 5,550, 8,700 and 9,900 stock options in 2020, 2019 and 2018, respectively, as antidilutive because the exercise price exceeded the average per share market price for the periods presented.