CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS Percentage	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenues
Lime and limestone operations (as a percent)	95.20%	90.60%	94.60%	91.00%
Natural gas interests (as a percent)	4.80%	9.40%	5.40%	9.00%
Total revenues (as a percent)	100.00%	100.00%	100.00%	100.00%
Cost of revenues:
Labor and other operating expenses (as a percent)	67.00%	62.60%	65.80%	62.00%
Depreciation, depletion and amortization (as a percent)	10.10%	9.20%	10.00%	9.70%
Total cost of revenues (as a percent)	77.10%	71.80%	75.80%	71.70%
Gross profit (as a percent)	22.90%	28.20%	24.20%	28.30%
Selling, general and administrative expenses (as a percent)	6.40%	5.60%	6.30%	6.10%
Operating profit (as a percent)	16.50%	22.60%	17.90%	22.20%
Other expense (income):
Interest expense (as a percent)	1.50%	1.70%	1.60%	1.80%
Other, net (as a percent)	(0.20%)	(0.10%)	(0.10%)	(0.10%)
Total other expense (income) (as a percent)	1.30%	1.60%	1.50%	1.70%
Income before income taxes (as a percent)	15.20%	21.00%	16.40%	20.50%
Income tax expense (as a percent)	4.10%	5.30%	4.40%	5.30%
Net income (as a percent)	11.10%	15.70%	12.00%	15.20%