Schedule II Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	$ 4,350	$ 4,361	$ 4,925	$ 5,640
Valuation Allowances and Reserves, Charged to Cost and Expense	509	72	332
Valuation Allowances and Reserves, Recoveries	(553)	(575)	(757)
Valuation Allowances and Reserves, Adjustments	$ 33	$ (61)	$ (290)

Total of the adjustments in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e24092-122690

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Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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Total of recoveries of amounts due the Entity that had previously been written off as uncollectible using allowances (the valuation accounts that are netted against the cost of an asset to value it at its carrying value) and total of reestablishments of reserves (liabilities established to represent expected future costs) that had previously been utilized.

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