Bank Note Payable, Term Loans Payable and Senior Notes (Details)											12 Months Ended
	Apr. 01, 2024 USD ($)	Aug. 10, 2023 USD ($)	Feb. 10, 2023 USD ($) $ / shares	Feb. 09, 2023 USD ($)	Sep. 06, 2022 USD ($)	Oct. 25, 2021 USD ($)	Sep. 30, 2021 USD ($)	Jun. 04, 2021 USD ($)	Dec. 24, 2020 USD ($)	Oct. 24, 2017 USD ($)	Dec. 31, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2021 USD ($) $ / shares	Oct. 01, 2023 USD ($)	Feb. 08, 2023	Nov. 30, 2021 USD ($)	Sep. 27, 2021	May 27, 2021 property	Dec. 23, 2020 USD ($)	Mar. 29, 2019 USD ($)	Mar. 07, 2019 USD ($)	Sep. 27, 2018 USD ($)	Aug. 02, 2018 USD ($)
Debt Instrument [Line Items]
Repayments of unsecured debt											$ 50,000,000	$ 110,000,000	$ 445,000,000
Loss on extinguishment of debt						$ 700,000					(106,000)	(78,000)	$ (901,000)
Unsecured term loan											114,707,000	$ 164,750,000
Received an aggregate amount											$ 4,206,000
Distributions common stock (in dollars per share) | $ / shares											$ 0.04	$ 0.20	$ 0.68
Borrowings outstanding											$ 90,000,000	$ 48,000,000
Office Properties in Atlanta, Georgia
Debt Instrument [Line Items]
Number of properties sold | property																		3
Senior Notes
Debt Instrument [Line Items]
Fixed charge coverage ratio										1.50
Series A Notes
Debt Instrument [Line Items]
Principal amount of loan										$ 116,000,000
Interest rate (as a percent)											4.49%
Series B Notes
Debt Instrument [Line Items]
Principal amount of loan										$ 84,000,000
Interest rate (as a percent)												4.76%
Maximum | Senior Notes
Debt Instrument [Line Items]
Unsecured leverage ratio										60.00%
Unsecured leverage ratio for significant acquisition										65.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate during period (as a percent)											8.47%
Weighted average interest rate (as a percent)													1.33%
Weighted average variable interest rate (as a percent)											8.05%
Borrowing capacity			$ 150,000,000	$ 237,500,000										$ 125,000,000
Borrowings outstanding			$ 40,000,000								$ 90,000,000	$ 0	$ 0
Facility fee at period end (as a percent)												0.35%
Facility fee (as a percent)			0.35%
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Cash dividend declared per share (in dollars per share) | $ / shares			$ 0.01
Revolving Credit Facility | ScenarioForecastMember
Debt Instrument [Line Items]
Borrowing capacity	$ 100,000,000
Revolving Credit Facility | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			3.00%
Unsecured leverage ratio												1.75%
Revolving Credit Facility | One Month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.11448%	0.11448%
Term of SOFR			1 month	1 month
Revolving Credit Facility | Three month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.26161%	0.26161%
Term of SOFR			3 months	3 months
Revolving Credit Facility | Six month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.42826%	0.42826%
Term of SOFR			6 months	6 months
Revolving Credit Facility | Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			2.00%
Unsecured leverage ratio												0.75%
BofA Line Of Credit | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)											0.50%
BofA Line Of Credit | One month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)											1.00%
Unsecured Debt [Member]
Debt Instrument [Line Items]
Principal amount of loan					$ 400,000,000
Repayments of unsecured debt					110,000,000	$ 200,000,000	$ 90,000,000
Loss on extinguishment of debt					$ 100,000
Unsecured term loan											$ 0
Weighted average interest rate (as a percent)													1.85%
Effective interest rate (as a percent)					2.65%								1.84%
Unsecured Debt [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)					1.75%
Fixed rate (as a percent)																	1.12%
Unsecured Debt [Member] | Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)					0.75%
JPM Term Loan
Debt Instrument [Line Items]
Principal amount of loan																							$ 150,000,000
Repayments of unsecured debt								$ 100,000,000	$ 50,000,000
Loss on extinguishment of debt								(100,000)
Unsecured term loan																			$ 100,000,000
Portion of future LIBOR-based rate risk																$ 100,000,000
JPM Term Loan | Hedged portion
Debt Instrument [Line Items]
Payment to terminate interest rate swap								$ 1,200,000
Portion of future LIBOR-based rate risk																				$ 100,000,000	$ 100,000,000
JPM Term Loan | LIBOR | Hedged portion
Debt Instrument [Line Items]
Fixed rate (as a percent)																				2.44%
BMO Term Loan
Debt Instrument [Line Items]
Principal amount of loan																						$ 220,000,000
Repayments of unsecured debt		$ 10,000,000
Unsecured term loan			$ 125,000,000								$ 115,000,000
Interest rate during period (as a percent)											8.47%
Weighted average interest rate (as a percent)											8.11%
Effective interest rate (as a percent)															4.04%
BMO Term Loan | Maximum
Debt Instrument [Line Items]
Cash dividend declared per share (in dollars per share) | $ / shares			$ 0.01
BMO Term Loan | ScenarioForecastMember
Debt Instrument [Line Items]
Repayment of principal	$ 15,000,000
BMO Term Loan | BMO Interest Rate Swap
Debt Instrument [Line Items]
Received an aggregate amount			$ 4,300,000
Interest receivable portion of proceeds from termination of interest rate swap			$ 100,000
BMO Term Loan | SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			3.00%
BMO Term Loan | One Month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.11448%
Term of SOFR			1 month
BMO Term Loan | Three month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.26161%
Term of SOFR			3 months
BMO Term Loan | Six month SOFR
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			0.42826%
Term of SOFR			6 months
BMO Term Loan | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate at period end (as a percent)												1.65%
BMO Term Loan | LIBOR | Hedged portion
Debt Instrument [Line Items]
Fixed rate (as a percent)			2.39%
BMO Term Loan | Bank's base rate
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			2.00%
Basis spread on variable rate at period end (as a percent)												0.65%
Tranche A Term Loan
Debt Instrument [Line Items]
Repayment of principal			$ 40,000,000