Employee Benefit Plans (Summary Of Pension Plans Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at prior valuation date	$ 116,695	$ 117,562
Service cost	621	500	$ 503
Interest cost	3,826	3,944	4,762
Benefits paid	(6,780)	(6,322)
Actuarial (gain) loss	6,305	1,011
Projected benefit obligation at valuation date	120,667	116,695	117,562
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at prior valuation date	99,537	99,325
Actual return on plan assets	9,564	6,513
Employer contributions	5,939	21
Benefits paid	(6,780)	(6,322)
Fair value of plan assets at valuation date	108,260	99,537	$ 99,325
Funded status and net amount recognized at valuation date	$ (12,407)	$ (17,158)