CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Lime and limestone operations (as a percent)	97.90%	96.50%	97.80%	96.00%
Natural gas (as a percent)	2.10%	3.50%	2.20%	4.00%
Total revenues (as a percent)	100.00%	100.00%	100.00%	100.00%
Cost of revenues:
Labor and other operating expenses (as a percent)	66.40%	63.50%	67.00%	65.20%
Depreciation, depletion and amortization (as a percent)	12.00%	9.50%	12.40%	9.60%
Total cost of revenues (as a percent)	78.40%	73.00%	79.40%	74.80%
Gross profit (as a percent)	21.60%	27.00%	20.60%	25.20%
Selling, general and administrative expenses (as a percent)	7.40%	6.30%	7.70%	6.10%
Operating profit (as a percent)	14.20%	20.70%	12.90%	19.10%
Other expenses (income):
Interest expense (as a percent)	1.80%	1.00%	1.50%	1.10%
Other expense (income), net (as a percent)	2.20%	(0.10%)	1.10%	(0.10%)
Total other expense (income) (as a percent)	4.00%	0.90%	2.60%	1.00%
Income before income taxes (as a percent)	10.20%	19.80%	10.30%	18.10%
Income tax expense (as a percent)	2.30%	5.00%	2.40%	4.60%
Net income (as a percent)	7.90%	14.80%	7.90%	13.50%