Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The consolidated financial statements include the accounts of the Company and its consolidated partnerships and wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. The Company presents its financial statements in accordance with accounting principles generally accepted in the United States (“GAAP”) as outlined in the Financial Accounting Standard Board’s Accounting Standards Codification (the “Codification” or “ASC”). The Codification is the single source of authoritative accounting principles applied by nongovernmental entities in the preparation of financial statements in conformity with GAAP. The Company evaluates all partnerships, joint ventures, and other arrangements with variable interests to determine if the entity or arrangement qualifies as a variable interest entity (“VIE”) as defined in the Codification. If the entity or arrangement qualifies as a VIE and the Company is determined to be the primary beneficiary, the Company is required to consolidate the assets, liabilities, and results of operations of the VIE. The Company had no investments or interests in any VIEs a
Cost Capitalization, Depreciation and Amortization	Cost Capitalization: Costs related to planning, developing, leasing, and constructing a property, including costs of personnel working directly on projects under development or redevelopment, are capitalized. In addition, the Company capitalizes interest to qualifying assets under development or redevelopment based on average accumulated expenditures outstanding during the period. In capitalizing interest to qualifying assets, the Company uses the interest incurred on specific project debt, if any. If there is no specific project debt, the Company uses its weighted average interest rate for non-project specific debt. The Company also capitalizes interest to investments in entities accounted for under the equity method when the entity has property under development or redevelopment with a carrying value in excess of the entity’s borrowings. To the extent debt exists within an unconsolidated joint venture during the construction period, the venture capitalizes interest on that venture-specific debt. The Company capitalizes interest, real estate taxes, and certain operating expenses on the unoccupied portion of development or redevelopment properties, which have ongoing construction of tenant improvements, until the earlier of the date on which the development project achieves 90% economic occupancy or one year from cessation of major construction activity. Depreciation and Amortization: Real estate assets are stated at depreciated cost less impairment, if any. Buildings are depreciated over their estimated useful lives, which range generally from 30 to 40 years. The life of a particular building depends upon a number of factors including whether the building was developed or acquired and the condition of the building upon acquisition. Furniture, fixtures, and equipment are depreciated over their estimated useful lives of three to five years. Tenant improvements, leasing costs, and leasehold improvements are generally amortized over the term of the applicable leases or the estimated useful life of the assets, whichever is shorter. The Company accelerates the depreciation of tenant improvements if it estimates that the lease term will end prior to the termination date, absent any expectation that the tenant improvements will be used by a successor tenant. This acceleration may occur if a tenant files for bankruptcy, vacates its premises, or defaults in another manner outlined in its lease. Deferred expenses are amortized over the period of estimated benefit. The Company uses the straight-line method for all depreciation and amortization.
Impairment	Impairment: We review our real estate assets on a property-by-property basis for impairment. This review includes our operating properties, properties under development, and land holdings. The first step in this process is to determine whether an asset is considered to be held-for-investment or held-for-sale, in accordance with accounting guidance. In order to be considered a real estate asset held-for-sale, we must, among other things, have the authority to commit to a plan to sell the asset in its current condition, have commenced the plan to sell the asset, and have determined that it is probable that the asset will sell within one year. If we determine that an asset is held-for-sale, we record an impairment loss if the fair value less costs to sell is less than the carrying amount. All real estate assets not meeting the held-for-sale criteria are considered to be held-for-investment. In the impairment analysis for assets held-for-investment, we must determine whether there are indicators of impairment. For operating properties, these indicators could include a significant decline in a property’s leasing percentage, a current period operating loss or negative cash flows combined with a history of losses at the property, a decline in lease rates for that property or others in the property’s market, a significant change in the market value of the property, an adverse change in the financial condition of significant tenants, or a significant decrease in the estimated hold period. For projects under development, indicators could include material budget overruns, significant delays in construction, occupancy, or stabilization timing, regulatory changes or economic trends that have a significant impact on the market, or an adverse change in the financial condition of significant future tenants. For land holdings, indicators could include an overall decline in the market value of land in the region, regulatory changes that impact ability to develop the land, a decline in development activity for the intended use of the land, or other adverse economic and market conditions.
Acquisition of Real Estate Assets	Acquisition of Real Estate Assets: The Company evaluates all real estate acquisitions to determine if the transactions qualify as an acquisition of assets or of a business. If the Company determines that substantially all of the fair value is concentrated in a single identifiable asset or group of similar assets, the Company will account for the acquisition as an acquisition of assets and not a business. If the Company determines that there is no single or group of assets that make up substantially all of the fair value of assets acquired, the Company must determine whether the acquired set of assets includes an input and substantial processes which create an output. Based on the facts of the transactions and guidance in ASC 805, if the Company determines that an input and substantial processes that create an output are present, the Company will account for the acquisition as an acquisition of a business. For asset acquisitions, the Company records the acquired tangible and intangible assets and assumed liabilities based on each asset and liability's relative fair value at the acquisition date to the total purchase price plus capitalized acquisition costs. For acquisitions that are accounted for as an acquisition of a business, the Company records the acquired tangible and intangible assets and assumed liabilities at fair value at the acquisition date, excluding any acquisition costs, which are expensed as incurred. The acquired assets and assumed liabilities for an operating property acquisition generally include but are not limited to: land, buildings and improvements, and identified tangible and intangible assets and liabilities associated with in-place leases, including leasing costs, value of above-market and below-market tenant leases, value of above-market and below-market ground leases, and acquired in-place lease values, if any. The fair value of land is derived from comparable sales of land within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements, and leasing costs are based upon current market replacement costs and other relevant market rate information. The fair value of the above-market or below-market component of an acquired lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining term and (ii) management’s estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition over the remaining term of the lease. The amounts recorded for above-market and below-market ground leases are included in intangible liabilities and intangible assets, respectively, and are amortized on a straight-line basis into rental property revenues over the remaining terms of the applicable leases. The fair value of acquired in-place leases is derived based on management’s assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in intangible assets and amortized as an increase to depreciation and amortization expense over the remaining term of the applicable leases.
Investment in Joint Ventures	Investment in Joint Ventures For joint ventures that the Company does not control, but over which it exercises significant influence, the Company uses the equity method of accounting. The Company's judgment with regard to its level of influence or control of an entity involves consideration of various factors including the form of its ownership interest; its representation in the entity's governance; its ability to participate in policy-making decisions; and the rights of other investors to participate in the decision-making process, to replace the Company as manager, and/or to liquidate the venture. These ventures are recorded at cost and adjusted for equity (losses) in earnings and cash contributions and distributions. Any difference between the carrying amount of these investments on the Company’s consolidated balance sheet and the underlying equity in net assets on the joint venture’s balance sheet is adjusted as the related underlying assets are depreciated, amortized, or sold. The Company generally allocates income and loss from an unconsolidated joint venture based on the venture's distribution priorities, which may be different from its stated ownership percentage. The Company evaluates the recoverability of its investment in unconsolidated joint ventures in accordance with accounting standards for equity investments by first reviewing each investment for any indicators of impairment. If indicators are present, the Company estimates the fair value of the investment. If the carrying value of the investment is greater than the estimated fair value, management makes an assessment of whether the impairment is “temporary” or “other-than-temporary.” In making this assessment, management considers the following: (i) the length of time and the extent to which fair value has been less than cost, (ii) the financial condition and near-term prospects of the entity, and (iii) the Company’s intent and ability to retain its interest long enough for a recovery in market value. If management concludes that the impairment is "other than temporary," the Company reduces the investment to its estimated fair value.
Noncontrolling Interest	Noncontrolling Interest The Company consolidates CPLP and certain joint ventures in which it owns a controlling interest. In cases where the entity’s documents do not contain a required redemption clause, the Company records the partner’s share of the entity in the equity section of the balance sheets in nonredeemable noncontrolling interests. In cases where the entity’s documents contain a provision requiring the Company to purchase the partner’s share of the venture at a certain value upon demand or at a future date, if any, the Company records the partner’s share of the entity in redeemable noncontrolling interests on the balance sheets. The outside partners' interests in CPLP are redeemable on a one-for-one basis, upon demand, into shares of common stock of the Company or, at the Company's sole discretion, into the cash equivalent of such share of common stock. Therefore, noncontrolling interests associated with CPLP are considered nonredeemable noncontrolling interests. The noncontrolling partners' share of all consolidated entities' income is reflected in net income attributable to noncontrolling interest on the statements of operations.
Revenue Recognition	Revenue Recognition Rental Property Revenues: The Company recognizes contractual revenues from leases on a straight-line basis over the term of the respective lease. Our leases regularly include allowances for tenant improvements. If we determine the improvements are our assets, we capitalize the cost of the improvements and recognize depreciation expense associated with such improvements over the shorter of the estimated useful life or the term of the lease. If the improvements are tenant assets, we defer the cost of improvements funded by us as a lease incentive asset and amortize it as a reduction of rental revenue over the term of the lease. Our determination of whether improvements are our assets or tenant assets also affects when we commence revenue recognition in connection with a lease. The Company records deferred revenue for the portion of company owned tenant improvements funded by or reimbursed by tenants and amortizes this amount on a straight-line basis into rental income over the term of the related lease. As of December 31, 2023 and 2022, the Company had unamortized deferred income related to tenant-funded tenant improvements of $141.0 million and $100.1 million, respectively, included in deferred income on the consolidated balance sheets. During 2023, 2022, and 2021, the Company recognized $20.0 million, $11.2 million, and $5.4 million, respectively, in revenues related to the amortization of tenant-funded tenant improvements. Certain leases also provide for percentage rents based upon the level of sales achieved by the lessee. Percentage rents are recognized once the specified sales target is achieved. In addition, leases typically provide for reimbursement of the tenants' share of real estate taxes, insurance, and other operating expenses to the Company. Operating expense reimbursements are recognized as the related expenses are incurred. Fee Income: The Company recognizes development, management, and leasing fees as it satisfies the related performance obligations under the respective contracts. The Company recognizes development and leasing fees received from investments in unconsolidated joint ventures and related salaries and other direct costs incurred by the Company as income and expense based on the percentage of the joint venture which the Company does not own. Correspondingly, the Company adjusts its investment in unconsolidated joint ventures when fees are paid to the Company by a joint venture in which the Company has an ownership interest. Gain on Investment Property Transactions: The Company recognizes a gain on the sale of investment property at the time the buyer obtains control of the investment property. If the Company maintains any continuing involvement with the investment property, that continuing involvement is considered to be one or more additional performance obligations and additional gains or losses will be recognized as these performance obligations are satisfied. When the Company gains control of a previously unconsolidated investment accounted for under the equity method of accounting, it records a gain for the difference between the carrying value of its equity method investment and the fair value of that investment on the date control is gained.
Receivables	The Company makes valuation adjustments to all tenant-related accounts receivable based upon its estimate of the likelihood of collectibility of amounts due from the tenant. The amount of any valuation adjustment is based on the tenant’s credit and business risk, history of payment, and other factors considered by management.
Income Taxes	Income Taxes The Company has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). To qualify as a REIT, the Company must distribute annually at least 90% of its adjusted taxable income, as defined in the Code, to its stockholders and satisfy certain other organizational and operating requirements. It is management’s current intention to adhere to these requirements and maintain the Company's REIT status. As a REIT, the Company generally will not be subject to federal income tax at the corporate level on the taxable income it distributes to its stockholders. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal income taxes at regular corporate rates and may not be able to qualify as a REIT for four subsequent taxable years. The Company may be subject to certain state and local taxes on its income and property, and to federal income taxes on its undistributed taxable income. CTRS is a C-Corporation for federal income tax purposes and uses the liability method for accounting for income taxes. Tax return positions are recognized in the financial statements when they are “more-likely-than-not” to be sustained upon examination by the taxing authority. Deferred income tax assets and liabilities result from temporary differences. Temporary differences are differences between the tax bases of assets and liabilities and their reported amounts in the financial statements that will result in taxable or deductible amounts in future periods. A valuation allowance may be placed on deferred income tax assets, if it is determined that it is more likely than not that a deferred tax asset may not be realized.
Stock Compensation	Stock Compensation The Company accounts for stock-based employee compensation using the fair value measurement method. We classify share-based payment awards granted in exchange for employee services as either equity awards or liability awards. Equity-classified awards are measured based on the fair value on the date of grant. Awards that are to be settled in cash are classified as liability awards. The value of all of the Company's share-based awards is recognized over the period during which an employee is required to provide services in exchange for the award - the requisite service period (usually the vesting period). No compensation costs are recognized for awards for which employees do not complete the requisite service period.
Derivative Financial Instruments	Derivative Financial Instruments The Company manages its exposure to interest rate risk associated with its floating-rate debt using derivative financial instruments, specifically interest rate swaps. The current interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount. The Company does not hold or issue derivative financial instruments for trading or speculative purposes. Derivatives are carried at fair value on the balance sheet as either other assets or other liabilities. If the hedging instrument is designated as a cash flow hedge and is determined to be highly effective, any gain or loss from changes in the fair value of the hedging instruments are reported as a component of other comprehensive income included in the equity section of the balance sheet. When the forecasted transaction occurs, the effective portion of the gain or loss on the hedge is reclassified from other comprehensive income to interest expense on the income statement. The Company regularly assesses the effectiveness of the hedge relationships between the hedging instrument and the underlying exposure being hedged. The Company also regularly assesses the effectiveness of its risk management strategies and its use of derivative financing instruments.
Earnings per Share	Earnings per Share Net income per share-basic is calculated as net income available to common stockholders divided by the weighted average number of common shares outstanding during the period, including nonvested restricted stock which has nonforfeitable dividend rights. Net income per share-diluted is calculated as net income available to common stockholders plus noncontrolling interests in CPLP divided by the diluted weighted average number of common shares outstanding during the period. Diluted weighted average number of common shares uses the same weighted average share number as in the basic calculation and adds the potential dilution that would occur if (i) the outside units in CPLP were converted into the Company's common stock, (ii) any forward sales contracts of our common stock were settled, and (iii) equity-based restricted stock units ("RSUs") as well as shares to be issued under the Employee Stock Purchase Plan (“ESPP”) were vested and settled resulting in additional common shares outstanding, all calculated using the treasury stock method, as applicable. RSUs are dilutive if the shares to be granted (assuming the end of the reporting period is the end of the measurement of any required market and performance achievement) exceed the shares assumed to be repurchased under the treasury stock method (using related unamortized compensation costs as proceeds). Shares to be issued under the ESPP are dilutive if the estimated shares to be purchased under the plan based on current enrollment elections exceed the shares assumed to be repurchased under the treasury stock method (using both employee ESPP contributions and related unamortized compensation costs as proceeds).
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include unrestricted cash and highly-liquid money market instruments. Highly-liquid money market instruments include securities and repurchase agreements with original maturities of three months or less, money market mutual funds, and United States Treasury Bills with maturities of 30 days or less.
Restricted Cash	Restricted Cash Restricted cash primarily includes escrow accounts held by lenders for reserves or funds to pay real estate taxes, if any. The Company did not have any restricted cash as of December 31, 2023 or 2022.
Determination of Fair Values	Determination of Fair Values The Company uses fair values in the preparation of the financial statements and related footnote disclosures under the Fair Value Hierarchy prescribed by GAAP. The hierarchy is used for disclosing fair values of debt as of the balance sheet date (see note 8) and recording cash flow hedges (see note 9). Both of these determinations are made based on Level 2 inputs, which are described more fully in the respective footnotes. Fair values used for stock compensation are based on the assumptions and methodologies described in note 14 and are excepted from the Fair Value Hierarchy disclosure requirements.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Reportable Segments	The Company's segments are based on the method of internal reporting which classifies operations by property type and geographical area. The segments by property type are: Office and Non-Office. The segments by geographical region are: Atlanta, Austin, Charlotte, Dallas, Phoenix, Tampa, and other markets. Included in other markets are properties located in Chapel Hill (sold in September 2022), Houston, Nashville, and Fort Worth (sold in April 2021). Included in Non-Office are retail and apartments in Chapel Hill (sold in September 2022) and Atlanta, as well as the College Street Garage in Charlotte. In the third quarter of 2021, with the sale of the Company's One South at the Plaza office property, the Company reassessed the segment for the College Street Garage and began to treat it as Non-Office for all periods presented. These reportable segments represent an aggregation of operating segments reported to the Chief Operating Decision Maker based on similar economic characteristics that include the type of property and the geographical location. Each segment includes both consolidated operations and the Company's share of joint venture operations. On November 27, 2023 the Financial Accounting Standards Board issued Accounting Standards Update 2023-07 "ASU 2023-07", "Segment Reporting" which amends the existing standard's disclosure requirements. Among other things, ASU 2023-07 will require companies to disclose significant segment expenses by reportable segment if they are regularly provided to the Chief Operating Decision Maker ("CODM") and disclosures of the CODM's title and position as well as details of how the CODM uses the reported measures. The amendments in ASU 2023-07 are effective for fiscal years beginning after December 15, 2023 and for interim periods beginning after December 15, 2024. The adoption of ASU 2023-07 will not have any material impact on the Company's financial statements. Company management evaluates the performance of its reportable segments in part based on net operating income (“NOI”). NOI represents rental property revenues, less termination fees, less rental property operating expenses. NOI is not a measure of cash flows or operating results as measured by GAAP, is not indicative of cash available to fund cash needs, and should not be considered an alternative to cash flows as a measure of liquidity. All companies may not calculate NOI in the same manner. The Company considers NOI to be an appropriate supplemental measure to net income as it helps both management and investors understand the core operations of the Company's operating assets. NOI excludes corporate general and administrative expenses, reimbursed expenses, interest expense, depreciation and amortization, impairments, gains/loss on sales of real estate, gain/loss on extinguishment of debt, transaction costs, and other non-operating items. Segment net income, amount of capital expenditures, and total assets are not presented in the following tables because management does not utilize these measures when analyzing its segments or when making resource allocation decisions.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Basis of Presentation: The consolidated financial statements include the accounts of the Company and its consolidated partnerships and wholly-owned subsidiaries. Intercompany transactions and balances have been eliminated in consolidation. The Company presents its financial statements in accordance with accounting principles generally accepted in the United States (“GAAP”) as outlined in the Financial Accounting Standard Board’s Accounting Standards Codification (the “Codification” or “ASC”). The Codification is the single source of authoritative accounting principles applied by nongovernmental entities in the preparation of financial statements in conformity with GAAP.

The Company evaluates all partnerships, joint ventures, and other arrangements with variable interests to determine if the entity or arrangement qualifies as a variable interest entity (“VIE”) as defined in the Codification. If the entity or arrangement qualifies as a VIE and the Company is determined to be the primary beneficiary, the Company is required to consolidate the assets, liabilities, and results of operations of the VIE. The Company had no investments or interests in any VIEs a

Cost Capitalization, Depreciation and Amortization

Cost Capitalization: Costs related to planning, developing, leasing, and constructing a property, including costs of personnel working directly on projects under development or redevelopment, are capitalized. In addition, the Company capitalizes interest to qualifying assets under development or redevelopment based on average accumulated expenditures outstanding during the period. In capitalizing interest to qualifying assets, the Company uses the interest incurred on specific project debt, if any. If there is no specific project debt, the Company uses its weighted average interest rate for non-project specific debt. The Company also capitalizes interest to investments in entities accounted for under the equity method when the entity has property under development or redevelopment with a carrying value in excess of the entity’s borrowings. To the extent debt exists within an unconsolidated joint venture during the construction period, the venture capitalizes interest on that venture-specific debt.

The Company capitalizes interest, real estate taxes, and certain operating expenses on the unoccupied portion of development or redevelopment properties, which have ongoing construction of tenant improvements, until the earlier of the date on which the development project achieves 90% economic occupancy or one year from cessation of major construction activity.

Depreciation and Amortization: Real estate assets are stated at depreciated cost less impairment, if any. Buildings are depreciated over their estimated useful lives, which range generally from 30 to 40 years. The life of a particular building depends upon a number of factors including whether the building was developed or acquired and the condition of the building upon acquisition. Furniture, fixtures, and equipment are depreciated over their estimated useful lives of three to five years. Tenant improvements, leasing costs, and leasehold improvements are generally amortized over the term of the applicable leases or the estimated useful life of the assets, whichever is shorter. The Company accelerates the depreciation of tenant improvements if it estimates that the lease term will end prior to the termination date, absent any expectation that the tenant improvements will be used by a successor tenant. This acceleration may occur if a tenant files for bankruptcy, vacates its premises, or defaults in another manner outlined in its lease. Deferred expenses are amortized over the period of estimated benefit. The Company uses the straight-line method for all depreciation and amortization.

Impairment

Impairment: We review our real estate assets on a property-by-property basis for impairment. This review includes our operating properties, properties under development, and land holdings.

The first step in this process is to determine whether an asset is considered to be held-for-investment or held-for-sale, in accordance with accounting guidance. In order to be considered a real estate asset held-for-sale, we must, among other things, have the authority to commit to a plan to sell the asset in its current condition, have commenced the plan to sell the asset, and have determined that it is probable that the asset will sell within one year. If we determine that an asset is held-for-sale, we record an impairment loss if the fair value less costs to sell is less than the carrying amount. All real estate assets not meeting the held-for-sale criteria are considered to be held-for-investment.

In the impairment analysis for assets held-for-investment, we must determine whether there are indicators of impairment. For operating properties, these indicators could include a significant decline in a property’s leasing percentage, a current period operating loss or negative cash flows combined with a history of losses at the property, a decline in lease rates for that property or others in the property’s market, a significant change in the market value of the property, an adverse change in the financial condition of significant tenants, or a significant decrease in the estimated hold period. For projects under development, indicators could include material budget overruns, significant delays in construction, occupancy, or stabilization timing, regulatory changes or economic trends that have a significant impact on the market, or an adverse change in the financial condition of significant future tenants. For land holdings, indicators could include an overall decline in the market value of land in the region, regulatory changes that impact ability to develop the land, a decline in development activity for the intended use of the land, or other adverse economic and market conditions.

Acquisition of Real Estate Assets

Acquisition of Real Estate Assets: The Company evaluates all real estate acquisitions to determine if the transactions qualify as an acquisition of assets or of a business. If the Company determines that substantially all of the fair value is concentrated in a single identifiable asset or group of similar assets, the Company will account for the acquisition as an acquisition of assets and not a business. If the Company determines that there is no single or group of assets that make up substantially all of the fair value of assets acquired, the Company must determine whether the acquired set of assets includes an input and substantial processes which create an output. Based on the facts of the transactions and guidance in ASC 805, if the Company determines that an input and substantial processes that create an output are present, the Company will account for the acquisition as an acquisition of a business.

For asset acquisitions, the Company records the acquired tangible and intangible assets and assumed liabilities based on each asset and liability's relative fair value at the acquisition date to the total purchase price plus capitalized acquisition costs. For acquisitions that are accounted for as an acquisition of a business, the Company records the acquired tangible and intangible assets and assumed liabilities at fair value at the acquisition date, excluding any acquisition costs, which are expensed as incurred. The acquired assets and assumed liabilities for an operating property acquisition generally include but are not limited to: land, buildings and improvements, and identified tangible and intangible assets and liabilities associated with in-place leases, including leasing costs, value of above-market and below-market tenant leases, value of above-market and below-market ground leases, and acquired in-place lease values, if any.

The fair value of land is derived from comparable sales of land within the same submarket and/or region. The fair value of buildings and improvements, tenant improvements, and leasing costs are based upon current market replacement costs and other relevant market rate information.

The fair value of the above-market or below-market component of an acquired lease is based upon the present value (calculated using a market discount rate) of the difference between (i) the contractual rents to be paid pursuant to the lease over its remaining term and (ii) management’s estimate of the rents that would be paid using fair market rental rates and rent escalations at the date of acquisition over the remaining term of the lease. The amounts recorded for above-market and below-market ground leases are included in intangible liabilities and intangible assets, respectively, and are amortized on a straight-line basis into rental property revenues over the remaining terms of the applicable leases.

The fair value of acquired in-place leases is derived based on management’s assessment of lost revenue and costs incurred for the period required to lease the “assumed vacant” property to the occupancy level when purchased. The amount recorded for acquired in-place leases is included in intangible assets and amortized as an increase to depreciation and amortization expense over the remaining term of the applicable leases.

Investment in Joint Ventures

For joint ventures that the Company does not control, but over which it exercises significant influence, the Company uses the equity method of accounting. The Company's judgment with regard to its level of influence or control of an entity involves consideration of various factors including the form of its ownership interest; its representation in the entity's governance; its ability to participate in policy-making decisions; and the rights of other investors to participate in the decision-making process, to replace the Company as manager, and/or to liquidate the venture. These ventures are recorded at cost and adjusted for equity (losses) in earnings and cash contributions and distributions. Any difference between the carrying amount of these investments on the Company’s consolidated balance sheet and the underlying equity in net assets on the joint venture’s balance sheet is adjusted as the related underlying assets are depreciated, amortized, or sold. The Company generally allocates income and loss from an unconsolidated joint venture based on the venture's distribution priorities, which may be different from its stated ownership percentage.

The Company evaluates the recoverability of its investment in unconsolidated joint ventures in accordance with accounting standards for equity investments by first reviewing each investment for any indicators of impairment. If indicators are present, the Company estimates the fair value of the investment. If the carrying value of the investment is greater than the estimated fair value, management makes an assessment of whether the impairment is “temporary” or “other-than-temporary.” In making this assessment, management considers the following: (i) the length of time and the extent to which fair value has been less than cost, (ii) the financial condition and near-term prospects of the entity, and (iii) the Company’s intent and ability to retain its interest long enough for a recovery in market value. If management concludes that the impairment is "other than temporary," the Company reduces the investment to its estimated fair value.

Noncontrolling Interest

The Company consolidates CPLP and certain joint ventures in which it owns a controlling interest. In cases where the entity’s documents do not contain a required redemption clause, the Company records the partner’s share of the entity in the equity section of the balance sheets in nonredeemable noncontrolling interests. In cases where the entity’s documents contain a provision requiring the Company to purchase the partner’s share of the venture at a certain value upon demand or at a future date, if any, the Company records the partner’s share of the entity in redeemable noncontrolling interests on the balance sheets. The outside partners' interests in CPLP are redeemable on a one-for-one basis, upon demand, into shares of common stock of the Company or, at the Company's sole discretion, into the cash equivalent of such share of common stock. Therefore, noncontrolling interests associated with CPLP are considered nonredeemable noncontrolling interests. The noncontrolling partners' share of all consolidated entities' income is reflected in net income attributable to noncontrolling interest on the statements of operations.

Revenue Recognition

Rental Property Revenues: The Company recognizes contractual revenues from leases on a straight-line basis over the term of the respective lease. Our leases regularly include allowances for tenant improvements. If we determine the improvements are our assets, we capitalize the cost of the improvements and recognize depreciation expense associated with such improvements over the shorter of the estimated useful life or the term of the lease. If the improvements are tenant assets, we defer the cost of improvements funded by us as a lease incentive asset and amortize it as a reduction of rental revenue over the term of the lease. Our determination of whether improvements are our assets or tenant assets also affects when we commence revenue recognition in connection with a lease. The Company records deferred revenue for the portion of company owned tenant improvements funded by or reimbursed by tenants and amortizes this amount on a straight-line basis into rental income over the term of the related lease. As of December 31, 2023 and 2022, the Company had unamortized deferred income related to tenant-funded tenant improvements of $141.0 million and $100.1 million, respectively, included in deferred income on the consolidated balance sheets. During 2023, 2022, and 2021, the Company recognized $20.0 million, $11.2 million, and $5.4 million, respectively, in revenues related to the amortization of tenant-funded tenant improvements.

Certain leases also provide for percentage rents based upon the level of sales achieved by the lessee. Percentage rents are recognized once the specified sales target is achieved. In addition, leases typically provide for reimbursement of the tenants' share of real estate taxes, insurance, and other operating expenses to the Company. Operating expense reimbursements are recognized as the related expenses are incurred.

Fee Income: The Company recognizes development, management, and leasing fees as it satisfies the related performance obligations under the respective contracts. The Company recognizes development and leasing fees received from investments in unconsolidated joint ventures and related salaries and other direct costs incurred by the Company as income and expense based on the percentage of the joint venture which the Company does not own. Correspondingly, the Company adjusts its investment in unconsolidated joint ventures when fees are paid to the Company by a joint venture in which the Company has an ownership interest.

Gain on Investment Property Transactions: The Company recognizes a gain on the sale of investment property at the time the buyer obtains control of the investment property. If the Company maintains any continuing involvement with the investment property, that continuing involvement is considered to be one or more additional performance obligations and additional gains or losses will be recognized as these performance obligations are satisfied.

When the Company gains control of a previously unconsolidated investment accounted for under the equity method of accounting, it records a gain for the difference between the carrying value of its equity method investment and the fair value of that investment on the date control is gained.

Receivables

The Company makes valuation adjustments to all tenant-related accounts receivable based upon its estimate of the likelihood of collectibility of amounts due from the tenant. The amount of any valuation adjustment is based on the tenant’s credit and business risk, history of payment, and other factors considered by management.

Income Taxes

The Company has elected to be taxed as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). To qualify as a REIT, the Company must distribute annually at least 90% of its adjusted taxable income, as defined in the Code, to its stockholders and satisfy certain other organizational and operating requirements. It is management’s current intention to adhere to these requirements and maintain the Company's REIT status. As a REIT, the Company generally will not be subject to federal income tax at the corporate level on the taxable income it distributes to its stockholders. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal income taxes at regular corporate rates and may not be able to qualify as a REIT for four subsequent taxable years. The Company may be subject to certain state and local taxes on its income and property, and to federal income taxes on its undistributed taxable income.

CTRS is a C-Corporation for federal income tax purposes and uses the liability method for accounting for income taxes. Tax return positions are recognized in the financial statements when they are “more-likely-than-not” to be sustained upon examination by the taxing authority. Deferred income tax assets and liabilities result from temporary differences. Temporary differences are differences between the tax bases of assets and liabilities and their reported amounts in the financial statements that will result in taxable or deductible amounts in future periods. A valuation allowance may be placed on deferred income tax assets, if it is determined that it is more likely than not that a deferred tax asset may not be realized.

Stock Compensation

The Company accounts for stock-based employee compensation using the fair value measurement method. We classify share-based payment awards granted in exchange for employee services as either equity awards or liability awards. Equity-classified awards are measured based on the fair value on the date of grant. Awards that are to be settled in cash are classified as liability awards. The value of all of the Company's share-based awards is recognized over the period during which an employee is required to provide services in exchange for the award - the requisite service period (usually the vesting period). No compensation costs are recognized for awards for which employees do not complete the requisite service period.

Derivative Financial Instruments

The Company manages its exposure to interest rate risk associated with its floating-rate debt using derivative financial instruments, specifically interest rate swaps. The current interest rate swaps involve the receipt of variable-rate amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount.

The Company does not hold or issue derivative financial instruments for trading or speculative purposes. Derivatives are carried at fair value on the balance sheet as either other assets or other liabilities. If the hedging instrument is designated as a cash flow hedge and is determined to be highly effective, any gain or loss from changes in the fair value of the hedging instruments are reported as a component of other comprehensive income included in the equity section of the balance sheet. When the forecasted transaction occurs, the effective portion of the gain or loss on the hedge is reclassified from other comprehensive income to interest expense on the income statement.

The Company regularly assesses the effectiveness of the hedge relationships between the hedging instrument and the underlying exposure being hedged. The Company also regularly assesses the effectiveness of its risk management strategies and its use of derivative financing instruments.

Earnings per Share

Net income per share-basic is calculated as net income available to common stockholders divided by the weighted average number of common shares outstanding during the period, including nonvested restricted stock which has nonforfeitable dividend rights. Net income per share-diluted is calculated as net income available to common stockholders plus noncontrolling interests in CPLP divided by the diluted weighted average number of common shares outstanding during the period. Diluted weighted average number of common shares uses the same weighted average share number as in the basic calculation and adds the potential dilution that would occur if (i) the outside units in CPLP were converted into the Company's common stock, (ii) any forward sales contracts of our common stock were settled, and (iii) equity-based restricted stock units ("RSUs") as well as shares to be issued under the Employee Stock Purchase Plan (“ESPP”) were vested and settled resulting in additional common shares outstanding, all calculated using the treasury stock method, as applicable. RSUs are dilutive if the shares to be granted (assuming the end of the reporting period is the end of the measurement of any required market and performance achievement) exceed the shares assumed to be repurchased under the treasury stock method (using related unamortized compensation costs as proceeds). Shares to be issued under the ESPP are dilutive if the estimated shares to be purchased under the plan based on current enrollment elections exceed the shares assumed to be repurchased under the treasury stock method (using both employee ESPP contributions and related unamortized compensation costs as proceeds).

Cash and Cash Equivalents

Cash and cash equivalents include unrestricted cash and highly-liquid money market instruments. Highly-liquid money market instruments include securities and repurchase agreements with original maturities of three months or less, money market mutual funds, and United States Treasury Bills with maturities of 30 days or less.

Restricted Cash

Restricted cash primarily includes escrow accounts held by lenders for reserves or funds to pay real estate taxes, if any. The Company did not have any restricted cash as of December 31, 2023 or 2022.

Determination of Fair Values

The Company uses fair values in the preparation of the financial statements and related footnote disclosures under the Fair Value Hierarchy prescribed by GAAP. The hierarchy is used for disclosing fair values of debt as of the balance sheet date (see note 8) and recording cash flow hedges (see note 9). Both of these determinations are made based on Level 2 inputs, which are described more fully in the respective footnotes. Fair values used for stock compensation are based on the assumptions and methodologies described in note 14 and are excepted from the Fair Value Hierarchy disclosure requirements.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Reportable Segments

The Company's segments are based on the method of internal reporting which classifies operations by property type and geographical area. The segments by property type are: Office and Non-Office. The segments by geographical region are: Atlanta, Austin, Charlotte, Dallas, Phoenix, Tampa, and other markets. Included in other markets are properties located in Chapel Hill (sold in September 2022), Houston, Nashville, and Fort Worth (sold in April 2021). Included in Non-Office are retail and apartments in Chapel Hill (sold in September 2022) and Atlanta, as well as the College Street Garage in Charlotte. In the third quarter of 2021, with the sale of the Company's One South at the Plaza office property, the Company reassessed the segment for the College Street Garage and began to treat it as Non-Office for all periods presented. These reportable segments represent an aggregation of operating segments reported to the Chief Operating Decision Maker based on similar economic characteristics that include the type of property and the geographical location. Each segment includes both consolidated operations and the Company's share of joint venture operations.

On November 27, 2023 the Financial Accounting Standards Board issued Accounting Standards Update 2023-07 "ASU 2023-07", "Segment Reporting" which amends the existing standard's disclosure requirements. Among other things, ASU 2023-07 will require companies to disclose significant segment expenses by reportable segment if they are regularly provided to the Chief Operating Decision Maker ("CODM") and disclosures of the CODM's title and position as well as details of how the CODM uses the reported measures. The amendments in ASU 2023-07 are effective for fiscal years beginning after December 15, 2023 and for interim periods beginning after December 15, 2024. The adoption of ASU 2023-07 will not have any material impact on the Company's financial statements.

Company management evaluates the performance of its reportable segments in part based on net operating income (“NOI”). NOI represents rental property revenues, less termination fees, less rental property operating expenses. NOI is not a measure of cash flows or operating results as measured by GAAP, is not indicative of cash available to fund cash needs, and should not be considered an alternative to cash flows as a measure of liquidity. All companies may not calculate NOI in the same manner. The Company considers NOI to be an appropriate supplemental measure to net income as it helps both management and investors understand the core operations of the Company's operating assets. NOI excludes corporate general and administrative expenses, reimbursed expenses, interest expense, depreciation and amortization, impairments, gains/loss on sales of real estate, gain/loss on extinguishment of debt, transaction costs, and other non-operating items.

Segment net income, amount of capital expenditures, and total assets are not presented in the following tables because management does not utilize these measures when analyzing its segments or when making resource allocation decisions.