Share Incentive Plans - Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation information
Compensation Expense	$ 23,174	$ 24,449	$ 27,132
Compensation Capitalized	1,527	1,450	1,218
Restricted Units In-Lieu of Bonus	1,743	3,266	4,418
Compensation Equity	26,444	29,165	32,768
Dividends Incurred	3,027	1,804	1,717
Restricted Shares [Member]
Compensation information
Compensation Expense	10,053	11,522	7,406
Compensation Capitalized	1,172	916	852
Restricted Units In-Lieu of Bonus	0	0	0
Compensation Equity	11,225	12,438	8,258
Dividends Incurred	1,172	979	754
Restricted Stock Units (RSUs) [Member]
Compensation information
Compensation Expense	10,103	9,905	12,310
Compensation Capitalized	80	240	36
Restricted Units In-Lieu of Bonus	1,743	3,265	1,663
Compensation Equity	11,926	13,410	14,009
Dividends Incurred	1,855	825	963
Options [Member]
Compensation information
Compensation Expense	2,156	2,420	6,683
Compensation Capitalized	193	254	296
Restricted Units In-Lieu of Bonus	0	1	2,755
Compensation Equity	2,349	2,675	9,734
Dividends Incurred	0	0	0
Employee Share Purchase Plan Discount [Member]
Compensation information
Compensation Expense	862	602	733
Compensation Capitalized	82	40	34
Restricted Units In-Lieu of Bonus	0	0	0
Compensation Equity	944	642	767
Dividends Incurred	$ 0	$ 0	$ 0

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Represents dividends paid during the period for each type of long term compensation outstanding.

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Amount of increase to additional paid-in capital (APIC) for recognition of cost for award under share-based payment arrangement.

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

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Amount of cost capitalized for award under share-based payment arrangement.

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Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

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