Investments	3 Months Ended
Investments	Mar. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]
Investments	Investments Unconsolidated Investments As of March 31, 2023, the Company had investments in six unconsolidated real estate entities with ownership interest percentages ranging from 20.0% to 50.0% and other unconsolidated investments including property technology and environmentally focused companies and investment management funds. The Company accounts for its unconsolidated investments under the equity method of accounting or under the measurement alternative with the carrying amount of the investment adjusted to fair value when there is an observable transaction for the same or similar investment of the same issuer indicating a change in fair value. The significant accounting policies of the Company's unconsolidated investments are consistent with those of the Company in all material respects. Certain of these investments are subject to various buy‑sell provisions or other rights which are customary in real estate joint venture agreements. The Company and its partners in these entities may initiate these provisions to either sell the Company's interest or acquire the interest from the Company's partner. Structured Investment Program In April 2022, the Company established its Structured Investment Program (the “SIP”), an investment platform through which the Company provides mezzanine loans or preferred equity to third-party multifamily developers in the Company's existing markets. As of March 31, 2023, the Company had commitments to fund three mezzanine loans of up to $92,375,000 in the aggregate. The mezzanine loans have a weighted average rate of return of 9.8% and mature at various dates on or before June 2026. At March 31, 2023, the Company had funded $42,074,000 of these commitments. The Company evaluates each SIP commitment to determine the classification as a loan or an investment in a real estate development project. As of March 31, 2023, all of the SIP commitments are classified as loans. The Company includes amounts outstanding under the SIP as a component of prepaid expenses and other assets on the accompanying Condensed Consolidated Balance Sheets. The Company evaluates the credit risk for each loan on an ongoing basis, estimating the reserve for credit losses using relevant available information from internal and external sources. Market-based historical credit loss data provides the basis for the estimation of expected credit losses, with adjustments, if necessary, for differences in current loan-specific risk characteristics, such as the amount of equity capital provided by a borrower, nature of the real estate being developed or other factors. For the three existing loans, interest is recognized as earned as interest income, and interest income and any change in the expected credit loss are included as a component of income from unconsolidated investments, on the accompanying Condensed Consolidated Statements of Comprehensive Income. Expensed Transaction, Development and Other Pursuit Costs The Company capitalizes costs associated with its development activities when future development is probable ("Development Rights") to the basis of land held, or if the Company has either not yet acquired the land or if the project is subject to a leasehold interest, the costs are capitalized as deferred development costs. Future development of these Development Rights is dependent upon various factors, including zoning and regulatory approval, rental market conditions, construction costs and the availability of capital. Costs incurred for pursuits for which future development is not yet considered probable are expensed as incurred. In addition, if the Company determines a Development Right is no longer probable, the Company recognizes any necessary expense to write down its basis in the Development Right. The Company expensed costs related to development pursuits not yet considered probable for development and the abandonment of Development Rights, as well as costs incurred in pursuing the acquisition or disposition of assets for which such acquisition and disposition activity did not occur, in the amounts of $2,992,000 and $987,000 for the three months ended March 31, 2023 and 2022, respectively. These costs are included in expensed transaction, development and other pursuit costs, net of recoveries on the accompanying Condensed Consolidated Statements of Comprehensive Income. These costs can vary greatly, and the costs incurred in any given period may be significantly different in future periods. Impairment of Long-Lived Assets and Casualty Loss The Company evaluates its real estate and other long-lived assets for impairment when potential indicators of impairment exist. Such assets are stated at cost, less accumulated depreciation and amortization, unless the carrying amount of the asset is not recoverable. If events or circumstances indicate that the carrying amount of an asset may not be recoverable, the Company assesses its recoverability by comparing the carrying amount of the asset to its estimated undiscounted future cash flows. If the carrying amount exceeds the aggregate undiscounted future cash flows, the Company recognizes an impairment loss to the extent the carrying amount exceeds the estimated fair value of the asset. Based on periodic tests of recoverability of long-lived assets, for the three months ended March 31, 2023 and 2022, the Company did not recognize any material impairment losses. For the three months ended March 31, 2023, the Company recognized a charge of $5,051,000 for the property and casualty damages across certain communities in its Northeast and California regions related to severe weather, reported as casualty loss on the accompanying Condensed Consolidated Statements of Comprehensive Income. The Company evaluates its for-sale condominium inventory for potential indicators of impairment, considering whether the fair value of the individual for-sale condominium units exceeds the carrying value of those units. For-sale condominium inventory is stated at the lower of cost or fair value. The Company determines the fair value of its for-sale condominium inventory as the estimated sales price less direct costs to sell. For the three months ended March 31, 2023 and 2022, the Company did not recognize any impairment losses on its for-sale condominium inventory. The Company assesses its portfolio of land held for both development and investment for impairment if the intent of the Company changes with respect to either the development of, or the expected holding period for, the land. For the three months ended March 31, 2023 and 2022, the Company did not recognize any impairment charges on its investment in land. The Company evaluates its unconsolidated investments for other than temporary impairment, considering both the extent and amount by which the carrying value of the investment exceeds the fair value, and the Company's intent and ability to hold the investment to recover its carrying value. The Company also evaluates its proportionate share of any impairment of assets held by unconsolidated investments. There were no other than temporary impairment losses recognized for any of the Company's unconsolidated investments for the three months ended March 31, 2023 and 2022.