Inventories (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Inventories carried at LIFO:
Finished goods	$ 46,860	$ 36,238
Raw materials, production parts and work-in-process	20,624	13,922
LIFO Reserve	(27,463)	(27,463)
LIFO Inventory Amount	40,021	22,697
Inventories carried at FIFO:
Finished goods	30,577	31,489
Raw materials, production parts and work-in-process	13,366	12,720
Total FIFO inventories	43,943	44,209
Total Inventories	$ 83,964	$ 66,906