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

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Share-Based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation [Line Items]
Total shares authorized	2,100,000
Shares available for future grants of stock options or restricted stock	1,600,000
Compensation Expense	$ 7,578,000	$ 8,338,000	$ 8,146,000
Stock awards granted during period	0	0	0
Stock Options
Share-based Compensation [Line Items]
Expiration period	10 years
Restricted Stock
Share-based Compensation [Line Items]
Unrecognized compensation cost related to unvested restricted stock	$ 12,900,000
Weighted average period during which unrecognized compensation cost is expected to be recognized (in years)	2 years 18 days
Granted	161,168	130,093	120,173
Restricted Stock \| Minimum [Member]
Share-based Compensation [Line Items]
Vesting period (in years)	1 year
Restricted Stock \| Maximum
Share-based Compensation [Line Items]
Vesting period (in years)	4 years
Restricted Stock Units (RSUs)
Share-based Compensation [Line Items]
Granted	0	0	0
Compensation Expense	$ 0	$ 1,000,000.0	$ 600,000
Restricted Stock Units (RSUs) \| Minimum [Member]
Share-based Compensation [Line Items]
Vesting period (in years)	3 years
Restricted Stock Units (RSUs) \| Maximum
Share-based Compensation [Line Items]
Vesting period (in years)	4 years