Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Lime and limestone inventories:
Raw materials	$ 6,394	$ 6,718
Finished goods	2,124	2,328
Total	8,518	9,046
Service parts inventories	5,032	5,081
Total inventories	$ 13,550	$ 14,127