Schedule II Valuation 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]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 819		$ 2,182		$ 1,420
Net Additions (Reductions) to Expense	29		(936)		1,063
Deductions	(54)	[1]	(427)	[1]	(301)	[1]
Balance at End of Period	$ 794		$ 819		$ 2,182

[1] Primarily consists of write-offs, net of recoveries and other adjustments