Employee Benefit Plans (Summary Of Assets Segregated By Level Of Valuation Inputs Within The Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Total	$ 16,360	$ 17,117	$ 17,435
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	10,930	11,973
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	4,828	4,529
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total	1,202	2,101
Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	1,202	2,101
Mutual funds/Investment funds
Defined Benefit Plan Disclosure [Line Items]
Total	5,421	6,063
Mutual funds/Investment funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	5,206	5,797
Mutual funds/Investment funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	215	266
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total	5,575	4,284
Common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	3,763	3,103
Common stocks | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	1,812	1,181
U.S. Government agencies
Defined Benefit Plan Disclosure [Line Items]
Total	301	514
U.S. Government agencies | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	301	514
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Total	1,277	971
Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	1,277	971
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Total	1,223	1,597
Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	1,223	1,597
Alternative investments
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets, Not Subject to Fair Value Hierarchy	602	615
Total	1,361	1,587
Alternative investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	759	972
Alternative investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Alternative investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	$ 0	$ 0