Schedule II - Valuation and Qualifying Accounts (Details) (Allowance for Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010		Dec. 31, 2009
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance Beginning of Year	$ 387	$ 1,150		$ 1,130
Charged to Cost and Expense	12	38		408
Deductions		(801)	[1]	(388)	[1]
Balance End of Year	$ 399	$ 387		$ 1,150

[1] Primarily payments and adjustments to required reserves.