CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenues
Lime and limestone operations (as a percent)	98.70%	97.70%
Natural gas (as a percent)	1.30%	2.30%
Total revenues (as a percent)	100.00%	100.00%
Cost of revenues:
Labor and other operating expenses (as a percent)	65.00%	67.60%
Depreciation, depletion and amortization (as a percent)	11.60%	12.90%
Total cost of revenues (as a percent)	76.60%	80.50%
Gross profit (as a percent)	23.40%	19.50%
Selling, general and administrative expenses (as a percent)	7.20%	8.00%
Operating profit (as a percent)	16.20%	11.50%
Other expenses (income):
Interest expense (as a percent)	0.10%	1.00%
Other income, net (as a percent)	(0.10%)	0.00%
Total other expense (income) (as a percent)	0.00%	1.00%
Income before income taxes (as a percent)	16.20%	10.50%
Income tax expense (as a percent)	4.10%	2.60%
Net income (as a percent)	12.10%	7.90%