Equity Plan - Unrecognized Compensation Cost - Nonvested Restricted Stock Awards (Details) - USD ($)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Unrecognized Compensation Cost
Total compensation cost	$ 2,519,000	$ 2,248,000	$ 1,924,000
Total income tax expense (benefit) on share-based compensation cost	(155,000)	$ 301,000	$ (146,000)
Restricted stock
Unrecognized Compensation Cost
Total unrecognized compensation cost related to nonvested restricted stock awards	$ 2,157,000
Expected weighted-average period for recognition of compensation costs related to nonvested restricted stock awards	1 year 8 months 23 days

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

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

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