Accounts And Other Receivables (Schedule Of Reconciliation Of The Beginning And Ending Balances Of The Allowance For Doubtful Accounts And Sales Returns) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Accounts and other receivables, allowance for doubtful accounts and sales returns	$ 2,937	$ 3,304
Customer receivables	127,664	123,439
Allowance For Doubtful Accounts
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of year	3,304	3,102	$ 3,746
Charges to expense	553	2,369	1,410
Recoveries	(56)	(857)	(32)
Write-offs and settlements	(710)	(1,322)	(2,167)
Foreign exchange and other	(154)	12	145
Balance, end of year	$ 2,937	$ 3,304	$ 3,102