Benefit Plans (Schedule Of Assumptions Used) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Assumptions used to determine benefit obligations: Discount rate	3.89%	4.06%	3.72%
Assumptions used to determine benefit obligations: Rate of compensation increase	4.00%	4.00%	4.00%
Assumptions used to determine net periodic benefit cost: Discount rate	3.89%	3.72%	4.76%
Assumptions used to determine net periodic benefit cost: Expected long-term return on plan assets	6.50%	6.50%	6.50%
Assumptions used to determine net periodic benefit cost: Rate of compensation increase	4.00%	4.00%	4.00%
Asset allocations as of measurement date:	100.00%	100.00%	100.00%
Value of shares (in thousands)		$ 68	$ 63
Percent of total plan assets	0.00%	0.40%	0.30%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	5.00%	9.00%	4.00%
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	33.00%	31.00%	33.00%
Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	8.00%	7.00%	8.00%
Municipal Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	42.00%	43.00%	45.00%
Investment Fund-Debt [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	9.00%	8.00%	8.00%
Insurance contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset allocations as of measurement date:	3.00%	2.00%	2.00%

Defined Benefit Plan Common Stock Percent Of Total Plan Assets

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- Definition

Defined Benefit Plan Common Stock Value Of Shares

+ References

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- Definition

The interest rate used to adjust for the time value of money for the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(1)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

The interest rate used to adjust for the time value of money.

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- Definition

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Expected Long-Term Rate of Return on Plan Assets
-URI http://asc.fasb.org/extlink&oid=6512046

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Expected rate of compensation increases (for pay-related plans).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (k)(2)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

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-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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