Accounts Receivable and Allowances For Doubtful, Accounts, Returns and Discounts (Details 1) (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]
Summary of activity in allowances for doubtful accounts, returns and discounts
Activity in allowances for doubtful accounts, Beginning Balance	$ 5,897	$ 5,163	$ 8,697
Activity in allowances for doubtful accounts, charges to Revenue	7,611	3,109	4,794
Activity in allowances for doubtful accounts, Charges to Expense	615	1,056	266
Activity in allowances for doubtful accounts, Deductions from Reserves	(5,871)	(3,431)	(8,594)
Activity in allowances for doubtful accounts, Ending Balance	$ 8,252	$ 5,897	$ 5,163

Valuation allowances and reserves charged to revenue accounts.

No definition available.

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- Details

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- Definition

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.

+ References

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

+ Details

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- Definition

+ References

+ Details

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- Definition

Total of the deductions 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 established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

+ References

+ Details

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