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Notes Payable, Bank Credit Facility, Interest Expense and Amortization of Deferred Debt Costs - Additional Information (Detail) |  |  |  |  |  |  |  |  | 12 Months Ended |  |  |  |
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Sep. 06, 2022 USD ($) | Aug. 24, 2022 USD ($) | Aug. 04, 2022 USD ($) | Jun. 07, 2022 USD ($) | Mar. 11, 2022 USD ($) | Nov. 19, 2021 USD ($) | Jun. 11, 2021 USD ($) | Jan. 05, 2021 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Oct. 01, 2030 | Oct. 01, 2027 | Aug. 23, 2022 USD ($) swap | Feb. 23, 2022 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Outstanding debt |  |  |  |  |  |  |  |  | $ 1,200,000,000 |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  | 961,577,000 | $ 941,456,000 |  |  |  |  |
Variable rate debt |  |  |  |  |  |  |  |  | 161,941,000 | 103,167,000 |  |  |  |  |
Long-term debt repayments of principal and balloon payments |  |  |  |  |  |  |  |  | 1,238,683,000 | 1,200,000,000 |  |  |  |  |
Debt outstanding with fixed-rate |  |  |  |  |  |  |  |  |  | 949,000,000 |  |  |  |  |
Debt outstanding with variable-rate |  |  |  |  |  |  |  |  |  | 206,000,000 |  |  |  |  |
Term loan facility payable |  |  |  |  |  |  |  |  | 99,382,000 | 99,233,000 |  |  |  |  |
Number of interest rate swaps | swap |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 |
Repayments of secured debt |  |  |  |  |  |  |  |  | 174,096,000 | 42,641,000 | $ 45,654,000 |  |  |  |
Loss on early extinguishment of debt |  |  |  |  |  |  |  |  | 648,000 | 0 | 0 |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 320,797,000 |  |  |  |  |  |
Payment for debt extinguishment or debt prepayment cost |  |  |  |  |  |  |  |  | 593,000 | 0 | 0 |  |  |  |
Unamortized deferred debt costs |  |  |  |  |  |  |  |  | 15,783,000 | 11,200,000 |  |  |  |  |
Accumulated amortization |  |  |  |  |  |  |  |  | 7,900,000 | 7,700,000 |  |  |  |  |
Capitalization of debt issuance cost |  |  |  |  |  |  |  |  | 9,900,000 | 6,400,000 | $ 1,200,000 |  |  |  |
Interest rate swaps |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative asset |  |  |  |  |  |  |  |  | $ 4,000,000 |  |  |  |  |  |
Revolving Credit Facility | Secured Overnight Financing Rate (SOFR) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  | 0.10% |  |  |  |  |  |
Revolving Credit Facility | London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  | 1.40% |  |  |  |  |  |
Term Facility | London Interbank Offered Rate (LIBOR) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate spread on LIBOR |  |  |  |  |  |  |  |  | 1.35% |  |  |  |  |  |
Unsecured Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Available borrowing capacity |  |  |  |  |  |  |  |  | $ 212,100,000 |  |  |  |  |  |
Term loan facility payable |  |  |  |  |  |  |  |  | 264,000,000 |  |  |  |  |  |
Letter of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term loan facility payable |  |  |  |  |  |  |  |  | 185,000 |  |  |  |  |  |
Line of Credit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  | 525,000,000 |  |  |  |  |  |
Line of Credit | Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  | 425,000,000 |  |  |  |  |  |
Line of Credit | Term Facility |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  | 100,000,000 |  |  |  |  |  |
Mortgages | Jamestown Place |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment for debt extinguishment or debt prepayment cost |  |  |  |  |  |  |  | $ 6,100,000 |  |  |  |  |  |  |
Mortgages | Hunt Club Corners |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment for debt extinguishment or debt prepayment cost |  |  |  |  |  |  | $ 5,000,000 |  |  |  |  |  |  |  |
Mortgage Notes Payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  | 2,000,000 | 41,000,000 |  |  |  |  |
Fixed rate mortgage notes payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed rate mortgages |  |  |  |  |  |  |  |  | 1,070,000,000.00 | 949,000,000 |  |  |  |  |
Variable rate loans payable |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Variable rate debt |  |  |  |  |  |  |  |  | $ 164,000,000 |  |  |  |  |  |
Term Loan | Secured Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000,000 |
Term Loan | Secured Debt | Agreement Ending October 1, 2030 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, notional amount |  |  |  |  |  |  |  |  |  |  |  |  |  | 50,000,000 |
Term Loan | Secured Debt | Agreement Ending October 1, 2027 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, notional amount |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 50,000,000 |
Term Loan | Secured Debt | Secured Overnight Financing Rate (SOFR) | Agreement Ending October 1, 2030 | Scenario, Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, fixed interest rate |  |  |  |  |  |  |  |  |  |  |  | 2.91% |  |  |
Term Loan | Secured Debt | Secured Overnight Financing Rate (SOFR) | Agreement Ending October 1, 2027 | Scenario, Forecast |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Derivative, fixed interest rate |  |  |  |  |  |  |  |  |  |  |  |  | 2.96% |  |
Construction-to-Permanent Loan | Secured Debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 133,000,000
Loan fixed interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.90%
Amortization schedule |  |  |  |  |  |  |  |  | 25 years |  |  |  |  |  |
Lansdowne Town Center Mortgage | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of secured debt |  |  |  |  | $ 28,300,000 |  |  |  |  |  |  |  |  |  |
Orchard Park Mortgage | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of secured debt |  |  |  | $ 8,600,000 |  |  |  |  |  |  |  |  |  |  |
Village Center Loan | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  | $ 25,300,000 |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  | 4.14% |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt, term |  |  | 15 years |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  |  | $ 135,200 |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, payment at maturity |  |  | 13,400,000 |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  |  | 11,200,000 |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  |  | $ 400,000 |  |  |  |  |  |  |  |  |  |  |  |
Great Falls Center Loan | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  | $ 31,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  | 3.91% |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule |  | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt, term |  | 7 years |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment |  | $ 164,700 |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, payment at maturity |  | 25,700,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt |  | 8,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of debt |  | $ 200,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Beacon Center and Seven Corners Loan | Mortgages |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount | $ 143,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate | 5.05% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amortization schedule | 25 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt, term | 15 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan required periodic principal and interest payment | $ 840,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, payment at maturity | 79,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of debt | 85,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, prepayment penalty | $ 5,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Broadlands Village |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  | $ 3,600,000 |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 28,900,000 |  |  |  |  |  |
Avenel Business Park |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  | 6,300,000 |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 22,900,000 |  |  |  |  |  |
Waycroft Construction Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Guarantor obligations, maximum exposure |  |  |  |  |  |  |  |  | 23,600,000 |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 152,700,000 |  |  |  |  |  |
Ashbrook Marketplace |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 20,800,000 |  |  |  |  |  |
Kentlands Square I |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Remaining loan balance |  |  |  |  |  |  |  |  | 28,200,000 |  |  |  |  |  |
Twinbrook Quarter | 3.80% Fixed Rate Loan Maturing In 2035 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan amount |  |  |  |  |  | $ 145,000,000 |  |  |  |  |  |  |  |  |
Amortization schedule |  |  |  |  |  | 25 years |  |  |  |  |  |  |  |  |
Twinbrook Quarter | 3.83% Fixed Rate Loan Maturing In 2041 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loan fixed interest rate |  |  |  |  |  | 3.83% |  |  |  |  |  |  |  |  |
Debt Covenant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notes payable to bank |  |  |  |  |  |  |  |  | $ 1,000,000,000 | $ 1,100,000,000 |  |  |  |  |
Credit agreement leverage ratio |  |  |  |  |  |  |  |  | 60.00% |  |  |  |  |  |
Interest coverage ratio required minimum |  |  |  |  |  |  |  |  | 2.0 |  |  |  |  |  |
Required fixed charge coverage ratio |  |  |  |  |  |  |  |  | 1.4 |  |  |  |  |  |

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