Summary of Inventories (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Finished products	$ 21,531	$ 20,382
In - process	11,073	9,513
Raw materials	16,694	16,507
Fine and fabricated precious metal in various stages of completion	13,224	9,599
Inventory, before LIFO reserve	62,522	56,001
LIFO reserve	(3,405)	(4,139)
Inventory, Net	$ 59,117	$ 51,862