Mortgages and Notes Payable - Summary of Mortgages and Notes Payable (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Mortgages and notes payable	$ 1,989,451	$ 1,450,551
Mortgages and notes payable, net	111,793	78,952
Secured Debt
Debt Instrument [Line Items]
Mortgages and notes payable	112,151	79,451
Debt issuance costs, net	$ (358)	(499)
Wilmington Trust National Association, Due February 28 \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2019-04
Maturity Date	2028-02
Debt instrument, interest rate	4.92%
Mortgages and notes payable	$ 49,065
Wilmington Trust National Association, Due August 25 \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2018-06
Maturity Date	2025-08
Debt instrument, interest rate	4.36%
Mortgages and notes payable	$ 20,318	20,674
PNC Bank \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2016-10
Maturity Date	2026-11
Debt instrument, interest rate	3.62%
Mortgages and notes payable	$ 17,885	18,260
Sun Life \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2012-03
Maturity Date	2021-10
Debt instrument, interest rate	5.13%
Mortgages and notes payable	$ 10,888	11,288
Aegon \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2012-04
Maturity Date	2023-10
Debt instrument, interest rate	6.38%
Mortgages and notes payable	$ 7,788	8,496
M&T Bank \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2017-10
Maturity Date	2021-08
Interest Rate	one - month LIBOR+3%
Mortgages and notes payable	$ 4,913	5,051
M&T Bank \| 1 Month LIBOR \| Secured Debt
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Notes holders \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2008-12
Maturity Date	2023-12
Debt instrument, interest rate	6.25%
Mortgages and notes payable	$ 750	750
Standard Insurance Company Due August 2030 \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2010-07
Maturity Date	2030-08
Debt instrument, interest rate	6.75%
Mortgages and notes payable	$ 544	563
Symetra Financial \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2017-11
Maturity Date	2026-10
Debt instrument, interest rate	3.65%
Mortgages and notes payable		6,467
Columbian Mutual Life Insurance Company \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2010-08
Maturity Date	2025-09
Debt instrument, interest rate	7.00%
Mortgages and notes payable		1,459
Legg Mason Mortgage Capital \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2010-08
Maturity Date	2022-08
Debt instrument, interest rate	7.06%
Mortgages and notes payable		4,692
Standard Insurance Company Due May 2034 \| Secured Debt
Debt Instrument [Line Items]
Origination Date	2009-04
Maturity Date	2034-05
Debt instrument, interest rate	6.88%
Mortgages and notes payable		$ 1,751

Debt instrument issuance date month and year.

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Debt instrument maturity date month and year.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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Contractual interest rate for funds borrowed, under the debt agreement.

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Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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