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, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of year	$ 7,317	$ 8,221	$ 8,906
Provision for Loan, Lease, and Other Losses	5,878	5,518	4,250
Financing Receivable, Allowance for Credit Losses, Write-downs	(6,504)	(6,422)	(4,935)
Balance at end of year	$ 6,691	$ 7,317	$ 8,221