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

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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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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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Share-Based Compensation - Plan Provisions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-Based Compensation
Compensation expense	$ 209	$ 285	$ 366	$ 371
Income tax benefit	$ 57	$ 78	$ 100	$ 101
Number of shares authorized	1,862,637		1,862,637
2010 Equity Incentive Plan \| Vesting period one
Share-Based Compensation
Vesting period			3 years
2010 Equity Incentive Plan \| Vesting period two
Share-Based Compensation
Vesting period			5 years
2010 Equity Incentive Plan \| Vesting period three
Share-Based Compensation
Vesting period			6 years