Stock-Based Compensation and Stock Repurchases (Schedule Of Restricted Stock Units Issued And Vested) (Details) - Restricted Stock Units (RSUs) [Member]	Mar. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	168,084
Number of options, Vested	97,156
Number of options, Unvested	70,928
March 10, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	62,528
Number of options, Vested	48,838
Number of options, Unvested	13,690
April 11, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	5,625
Number of options, Vested	1,406
Number of options, Unvested	4,219
March 23, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	63,144
Number of options, Vested	46,912
Number of options, Unvested	16,232
August 29, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	7,394
Number of options, Unvested	7,394
January 2, 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	29,393
Number of options, Unvested	29,393
Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	95,221
Directors [Member] \| March 10, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	35,147
Directors [Member] \| March 23, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	30,681
Directors [Member] \| January 2, 2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	29,393
Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	72,863
Management [Member] \| March 10, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	27,381
Management [Member] \| April 11, 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	5,625
Management [Member] \| March 23, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	32,463
Management [Member] \| August 29, 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Grants	7,394

Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Vested And Nonvested, Outstanding, Number

No definition available.

+ Details

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- Definition

Share-based Compensation Arrangement By Share-based Payment Award, Equity Instruments Other Than Options, Vested, Outstanding, Number

+ References

No definition available.

+ Details

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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.

+ References

No definition available.

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