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

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Share-based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restricted Shares [Member]
Stock Based Compensation [Abstract]
Unrecognized compensation cost	$ 238,000	$ 241,000	$ 238,000	$ 241,000
Stock Incentive Plan [Member]
Stock Based Compensation [Abstract]
Number of shares authorized (in shares)	350,000		350,000
Stock Incentive Plan [Member] \| Restricted Shares [Member]
Stock Based Compensation [Abstract]
Recognition period for total unrecognized compensation costs			3 years
Stock Incentive Plan [Member] \| Restricted Shares [Member] \| Nonemployee Director [Member]
Stock Based Compensation [Abstract]
Compensation expense	$ 34,400	39,600	$ 158,800	168,800
Stock Incentive Plan [Member] \| Performance-Based Restricted Stock Units [Member]
Stock Based Compensation [Abstract]
Unrecognized compensation cost	99,000	188,000	99,000	188,000
Stock Incentive Plan [Member] \| Performance-Based Restricted Stock Units [Member] \| Certain Executive Officers [Member]
Stock Based Compensation [Abstract]
Compensation expense	$ 13,100	$ 28,400	$ (98,900)	$ 53,700