Nature Of Operations And Significant Accounting Policies (Summary Of Allowance For Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Nature Of Operations And Significant Accounting Policies [Abstract]
Balance at beginning of year	$ 8,221	$ 8,906	$ 8,081
Provisions	5,518	4,250	7,203
Deductions	(6,422)	(4,935)	(6,378)
Balance at end of year	$ 7,317	$ 8,221	$ 8,906

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A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-URI http://asc.fasb.org/extlink&oid=6965416&loc=SL6953423-111524

-Subparagraph (c)(1)

+ Details

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- Definition

Charge to expense for financing receivables that are expected to be uncollectible.

+ References

+ Details

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- Definition

Reduction to the allowance for credit losses related to financing receivables deemed uncollectible.

+ References

+ Details

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