Stock Incentive Plan - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of authorized stock for stock incentive plan (in shares)	350,000		350,000
Stock-based compensation expense			$ 351,000	$ 412,000
Shares issued upon exercise of stock options (in shares)	0	996	1,723	996
Proceeds from stock option exercises		$ 0		$ 0
Shares withheld for stock option exercises and related income taxes, amount withheld	$ 0	$ 73,000	$ 49,000
Options granted (in shares)	0	0	0	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, options, contractual term			10 years
Stock incentive plan vesting period, years			3 years
Stock-based compensation expense	$ 33,000	$ 32,000	$ 65,000	$ 108,000
Cashless Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from stock option exercises	0	56,000	$ 66,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock incentive plan vesting period, years			3 years
Stock-based compensation expense	$ 122,000	$ 126,000	$ 286,000	$ 304,000
Restricted units granted (in shares)	0	0	0	0

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

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Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP).

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