Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Raw materials and work in process	$ 46,663	$ 66,221
Supplies and service parts	55,453	72,551
Finished products	58,337	68,335
Inventory at FIFO cost	160,453	207,107
Excess of FIFO cost over LIFO cost	(26,187)	(27,429)
Total inventory, net	$ 134,266	$ 179,678