Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Summary of Significant Accounting Policies

Schedule of supplemental cash flow information (in thousands)

	Years Ended December 31,
	2021		2020		2019
Cash paid during the year for:
Interest	$	151	$	152	$	150
Income taxes	$	9,483	$	975	$	445

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

	2021		2020
Beginning balance	$	398	$	361
Additions		66		60
Adjustments for expected credit loss factors		(14)		—
Write-offs		—		(23)
Ending balance	$	450	$	398

Schedule of inventories, net

	December 31,
	2021		2020
Lime and limestone inventories:
Raw materials	$	3,232	$	4,279
Finished goods		2,677		2,866
		5,909		7,145
Service parts inventories		9,207		8,065
	$	15,116	$	15,210

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,
	2021		2020
Personnel related expenses	$	2,344	$	2,340
Income taxes		—		990
Other taxes		1,374		985
Other		1,138		1,494
	$	4,856	$	5,809

Schedule of computation of basic and diluted income per common share

	Years Ended December 31,
	2021		2020		2019
Net income for basic and diluted income per common share	$	37,045	$	28,223	$	26,056
Weighted-average shares for basic income per common share		5,656,367		5,629,425		5,612,048
Effect of dilutive securities:
Employee and director stock options(1)		11,992		10,438		9,090
Adjusted weighted-average shares and assumed exercises for diluted income per common share		5,668,359		5,639,863		5,621,138
Basic net income per common share	$	6.55	$	5.01	$	4.64
Diluted net income per common share	$	6.54	$	5.00	$	4.64

(1) Excludes 600, 5,550 and 8,700 stock options in 2021, 2020 and 2019, respectively, as antidilutive because the exercise price exceeded the average per share market price for the periods presented.