Inventories (Details) (USD $)	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011
Inventories [Abstract]
Inventories-gross		$ 110,087,000
Impaired inventory		(31,360,000)
Inventory, gross, total		78,727,000
Inventories included in other assets		(1,426,000)
Inventories, net		77,301,000
Inventory impairment charges	$ 4,300,000