Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amount
Income taxes computed at the federal statutory rate	$ 8,266	$ 6,118	$ 9,073
(Reduction) increase in taxes resulting from:
Statutory depletion in excess of cost depletion	(1,854)	(1,708)	(2,139)
Manufacturing deduction	(666)	(548)	(574)
State income taxes, net of federal income tax benefit	202	309	104
Other	(84)	424	91
Income tax expense	$ 5,864	$ 4,595	$ 6,555
Percent of Pretax Income
Income taxes computed at the federal statutory rate (as a percent)	35.00%	35.00%	35.00%
(Reduction) increase in taxes resulting from (as a percent):
Statutory depletion in excess of cost depletion (as a percent)	(7.90%)	(9.80%)	(8.20%)
Manufacturing deduction (as a percent)	(2.80%)	(3.10%)	(2.20%)
State income taxes, net of federal income tax benefit (as a percent)	0.90%	1.80%	0.40%
Other (as a percent)	(0.40%)	2.40%	0.30%
Income tax expense (as a percent)	24.80%	26.30%	25.30%
Deferred tax liabilities
Lime and limestone property, plant and equipment	$ 17,907	$ 18,833
Natural gas interests drilling costs and equipment	2,811	3,101
Total	20,718	21,934
Deferred tax assets
Alternative minimum tax credit carry forwards	296	2,259
Fair value liability of foreign exchange hedges	129
Other	461	491
Total	886	2,750
Deferred tax liabilities, net, Total	19,832	19,184
Current income taxes:
Prepaid expenses and other current assets	75	286
Deferred income taxes:
Deferred tax liabilities, net	19,832	19,184
Current income tax expense	5,087	4,822	$ 5,282
Deferred income tax expense (benefit)	777	(227)	1,273
Income tax expense	5,864	$ 4,595	$ 6,555
Federal
Operating loss carry forwards
Net operating loss carryforwards	$ 0