Summary Of Significant Accounting Policies (Summary Of Adjustments In Allowances For Doubtful Accounts And Sales Adjustments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Abstract]
Balance at beginning of year	$ 990	$ 1,603	$ 2,389
Provisions for losses - accounts receivable	961	805	1,161
Collection of accounts previously reserved		(142)	4
Deductions for accounts charged off or credits issued	(330)	(1,276)	(1,951)
Balance at end of year	$ 1,621	$ 990	$ 1,603