CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues
Lime and limestone operations (as a percent)	96.50%	95.80%	96.00%	95.60%
Natural gas interests (as a percent)	3.50%	4.20%	4.00%	4.40%
Total revenues (as a percent)	100.00%	100.00%	100.00%	100.00%
Cost of revenues:
Labor and other operating expenses (as a percent)	63.50%	64.30%	65.20%	66.30%
Depreciation, depletion and amortization (as a percent)	9.50%	10.20%	9.60%	10.90%
Total cost of revenues (as a percent)	73.00%	74.50%	74.80%	77.20%
Gross profit (as a percent)	27.00%	25.50%	25.20%	22.80%
Selling, general and administrative expenses (as a percent)	6.30%	6.50%	6.10%	6.70%
Operating profit (as a percent)	20.70%	19.00%	19.10%	16.10%
Other expense (income):
Interest expense (as a percent)	1.00%	1.40%	1.10%	1.40%
Other, net (as a percent)	(0.10%)	(0.10%)	(0.10%)	(0.20%)
Total other expense (income) (as a percent)	0.90%	1.30%	1.00%	1.20%
Income before income taxes (as a percent)	19.80%	17.70%	18.10%	14.90%
Income tax expense (as a percent)	5.00%	4.60%	4.60%	3.80%
Net income (as a percent)	14.80%	13.10%	13.50%	11.10%