Valuation and Qualifying Accounts (Details) (Allowance for doubtful accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for doubtful accounts [Member]
Schedule of valuation and qualifying accounts
Beginning of Period	$ 21	$ 97	$ 207
Costs and Expenses	113	(71)	(40)
Deductions/Write-offs	0	5	70
End of Period	$ 134	$ 21	$ 97