Stock-Based Compensation - Long Term Incentive Plan $ / shares in Units, $ in Thousands	9 Months Ended
Sep. 30, 2020 USD ($) $ / shares shares
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted (in shares)	32,625
Award vesting period	3 years
Unrecognized compensation costs \| $	$ 200
Performance Shares \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio, percent of target	0.00%
Performance Shares \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Conversion ratio, percent of target	200.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Number of RSUs granted in period (in shares)	33,426
Weighted-average grant date fair value (in dollars per share) \| $ / shares	$ 70.94
Unrecognized compensation costs \| $	$ 4,000
A 2019 Award and 2020 Award [Member] \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense \| $	$ 0
Target Achieved [Member] \| A 2020 Award [Member] \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Award Target Share	31,830
Target Achieved [Member] \| A 2019 Award [Member] \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Award Target Share	35,170

The target number of shares to be awarded under the plan if performance goals are achieved.

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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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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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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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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Net number of non-option equity instruments granted to participants.

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