Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for doubtful accounts [Member]
Valuation and Qualifying Accounts [Abstract]
Balance at Beginning of Period	$ 141	$ 176	$ 428
Charged to Costs and Expenses	379	6	61
Charged to Other Accounts	0	0	0
Deductions	(4)	(41)	(313)
Other	3	0	0
Balance at End of Period	519	141	176
Valuation allowance against gross deferred income tax assets [Member]
Valuation and Qualifying Accounts [Abstract]
Balance at Beginning of Period	3,042	1,853	2,465
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	11	1,368	54
Deductions	(132)	(178)	(655)
Other	(34)	(1)	(11)
Balance at End of Period	$ 2,887	$ 3,042	$ 1,853