Employee Benefit Plans (Restricted Shares Activity And Related Information) (Details) - Restricted Stock - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense associated with restricted shares	$ 935	$ 787
Unrecognized stock-based compensation expense associated with restricted shares	$ 5,349
Weighted average period (in years) in which the above amount is expected to be recognized	3 years 6 months
Restricted Awards, Number of Awards [Roll Forward]
Beginning Balance	152,692	170,033
Granted	31,006	28,363
Vested	(41,657)	(47,104)
Ending Balance	142,041	151,292
Restricted Awards, Number of Awards, Weighted Average Exercise Price [Roll Forward]
Outstanding at January 1	$ 51.85	$ 44.34
Granted	79.86	70.03
Vested	39.79	37.45
Outstanding at June 30	$ 61.50	$ 51.30

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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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.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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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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