Stock-based Compensation - Narrative (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation	$ 1,136,000	$ 3,155,000	$ 3,836,000
Expected cost on shares expected to vest	$ 2,995,000
Recognition period for compensation expense not yet recognized	3 years 2 months 12 days
Weighted average shares granted (usd per share)	$ 16.72	$ 18.63	$ 27.05
Fully Vested and Restricted Stock \| Director
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation	$ 576,000	$ 526,000	$ 880,000
Granted (shares)	50,316	21,532	24,427
Weighted average shares granted (usd per share)	$ 12.79	$ 24.38	$ 23.64
Deferred Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Granted (shares)	12,058	12,304	14,914
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award
Granted (shares)	104,789	62,125	62,320
Restricted Stock \| Vesting period one
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period	4 years
Restricted Stock \| Vesting period two
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period	3 years
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period	3 years
Granted (shares)	105,857	89,092	65,421
Restricted Stock And Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation	$ 557,000	$ 2,630,000	$ 2,956,000
Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation	$ 0	$ 0
Share-based compensation, number of shares authorized (shares)	2,058,000
Shares granted in period (shares)	0	0	0
Omnibus Plan \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period	10 years
Omnibus Plan \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award
Vesting period	1 year

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

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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 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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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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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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Number of shares authorized for issuance under share-based payment arrangement.

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Gross number of share options (or share units) granted during the period.

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