Accounts Receivable (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	$ 95,297	$ 73,342
Less allowance for doubtful accounts	(2,409)	(1,071)
Accounts receivable, net	92,888	72,271
Trade Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	54,010	37,999
Unpaid Amounts For Benefit Services
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	$ 41,287	$ 35,343