Description of Business and Basis of Presentation	12 Months Ended
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Description of Business: Cousins Properties Incorporated (“Cousins”), a Georgia corporation, is a self-administered and self-managed real estate investment trust (“REIT”). Cousins conducts substantially all of its business through Cousins Properties, LP ("CPLP"). Cousins owns approximately 98% of CPLP and consolidates CPLP. CPLP owns Cousins TRS Services LLC ("CTRS") a taxable entity which owns and manages its own real estate portfolio and performs certain real estate related services for other parties. Cousins, CPLP, CTRS and their subsidiaries (collectively, the “Company”) develop, acquire, lease, manage, and own primarily Class A office properties and opportunistic mixed-use developments in Sunbelt markets with a focus on Georgia, Texas, Arizona, Florida, and North Carolina. As of December 31, 2017, the Company’s portfolio of real estate assets consisted of interests in 14.2 million square feet of office space and 310,000 square feet of mixed-use space. 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. For the three years ended December 31, 2017, there were no items of other comprehensive income. Therefore, no presentation of comprehensive income is required. 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. In 2017, the Company transferred the right to sell a building to a special purpose entity to facilitate a potential Section 1031 exchange under the Internal Revenue Code of 1986, as amended (the "Code"), and the special purpose entity sold the building and retained the proceeds therefrom. To realize the tax deferral available under the Section 1031 exchange, the Company must complete the Section 1031 exchange, and take title to the to-be-exchanged building within 180 days of the disposition date. The Company has determined that this entity is a VIE, and the Company is the primary beneficiary. Therefore, the Company consolidates this entity. As of December 31, 2017, this VIE had total assets of $56.7 million, no significant liabilities, and no significant cash flows. In addition, the Company considers CPLP to be a VIE with the Company as the primary beneficiary. Recently Issued Accounting Standards: In May 2014, the FASB issued ASU 2014-09 ("ASC 606"), "Revenue from Contracts with Customers." Under the new guidance, companies will recognize revenue when the seller satisfies a performance obligation, which would be when the buyer takes control of the good or service. ASU 2015-14 (collectively with ASU 2014-09, "ASC 606"), "Revenue from Contracts with Customers," was subsequently issued modifying the effective date to periods beginning after December 15, 2017, with early adoption permitted for periods beginning after December 15, 2016. The standard allows for either "full retrospective" adoption, meaning the standard is applied to all of the periods presented, or "modified retrospective" adoption, meaning the standard is applied only to the most recent period presented in the financial statements. The Company adopted this guidance using the “modified retrospective” method effective January 1, 2018. The classification of certain non-lease components of revenue from leases may be impacted by the new revenue standard upon the adoption of the new leasing standard beginning January 1, 2019 (see below). The Company has determined that the adoption of ASC 606 will not require any material adjustments to the consolidated financial statements but will result in additional disclosures related to disaggregation of revenue streams beginning in the first quarter of 2018. In February 2016, the FASB issued ASU 2016-02, "Leases," which amends the existing standards for lease accounting by requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting and reporting. The new standard will require lessees to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months and classify such leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method (finance leases) or on a straight-line basis over the term of the lease (operating leases). Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases, and operating leases. ASU 2016-02 supersedes previous leasing standards. The guidance is effective for the fiscal years beginning after December 15, 2018, with early adoption permitted. The Company expects to adopt this guidance using the "modified retrospective" method effective January 1, 2019, and is currently assessing the potential impact of adopting the new guidance. In August 2016, the FASB issued ASU 2016-15, "Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15") which updated ASC Topic 230, "Statement of Cash Flows." ASU 2016-15 clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows to reduce diversity in practice with respect to (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard in the fourth quarter of 2017 with retrospective application to the consolidated statements of cash flows. The Company elected to use the nature of distributions approach for distributions from its equity method investments, under which it classifies the distribution received on the basis of the nature of the activity that generated the distribution. The adoption of this new approach resulted in an increase in net cash provided by operating activities and a decrease in net cash provided by investing activities of $6.4 million and $2.9 million for the years ended December 31, 2016 and 2015, respectively. In November 2016, the FASB issued ASU 2016-18, "Restricted Cash" ("ASU 2016-18") which updated ASC Topic 230, "Statement of Cash Flows." ASU 2016-18 requires companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company has early adopted this standard in the fourth quarter of 2017, which resulted in an increase in net cash provided by investing activities by $11.3 million for the year ended December 31, 2016 and a decrease in net cash provided by operating and investing activities by $263,000 and $475,000, respectively, for the year ended December 31, 2015. Effective January 1, 2017, the Company adopted ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting." Under this ASU, the additional paid-in capital pool is eliminated, and an entity recognizes all excess tax benefits and tax deficiencies as income tax expense or benefit in the income statement. This ASU also eliminated the requirement to defer recognition of an excess tax benefit until all benefits are realized through a reduction to taxes payable. In the first quarter of 2017, the Company changed the treatment of excess tax benefits as operating cash flows in the statement of cash flows. This ASU also stipulates that cash payments to tax authorities in connection with shares withheld to meet statutory tax withholding requirements be presented as a financing activity in the statement of cash flows. This ASU was adopted prospectively, prior periods have not been restated to conform to the current period presentation. In January 2017, the FASB issued ASU 2017-01, "Clarifying the Definition of a Business," which provides a more narrow definition of a business to be used in determining the accounting treatment of an acquisition. As a result, many acquisitions that previously qualified as business combinations will be treated as asset acquisitions. For asset acquisitions, acquisition costs may be capitalized, and the purchase price may be allocated on a relative fair value basis. ASU 2017-01 is effective prospectively for the Company on January 1, 2018, with early adoption permitted. The Company adopted this standard in 2017 and expects that most of its future acquisitions will qualify as asset acquisitions. In February 2017, the FASB issued ASU No. 2017-05, “Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets” (“ASU 2017-05”). ASU 2017-05 updates the definition of an “in substance nonfinancial asset” and clarifies the derecognition guidance for nonfinancial assets to conform with the new revenue recognition standard. Among other things, ASU 2017-05 requires companies to recognize 100% of the gain on the transfer of a nonfinancial asset to an entity in which it has a noncontrolling interest. ASU 2017-05 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company adopted this guidance using the "modified retrospective" method effective on January 1, 2018. As a result of the adoption of ASU 2017-05, the Company recorded a cumulative effect from change in accounting principle which credited distributions in excess of cumulative net income by $24.3 million. This cumulative effect adjustment resulted from the 2013 transfer of a wholly-owned property to an entity in which it had a noncontrolling interest. In May 2017, FASB issued ASU 2017-09, "Scope of Modification Accounting," which amends the scope of modification accounting for share-based payment arrangements and provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASC 718, "Compensation—Stock Compensation." This update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard on January 1, 2018. Adoption of the standard did not have a material impact on the Company's financial statements.

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION

Description of Business: Cousins Properties Incorporated (“Cousins”), a Georgia corporation, is a self-administered and self-managed real estate investment trust (“REIT”). Cousins conducts substantially all of its business through Cousins Properties, LP ("CPLP"). Cousins owns approximately 98% of CPLP and consolidates CPLP. CPLP owns Cousins TRS Services LLC ("CTRS") a taxable entity which owns and manages its own real estate portfolio and performs certain real estate related services for other parties.

Cousins, CPLP, CTRS and their subsidiaries (collectively, the “Company”) develop, acquire, lease, manage, and own primarily Class A office properties and opportunistic mixed-use developments in Sunbelt markets with a focus on Georgia, Texas, Arizona, Florida, and North Carolina. As of December 31, 2017, the Company’s portfolio of real estate assets consisted of interests in 14.2 million square feet of office space and 310,000 square feet of mixed-use space.

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.

For the three years ended December 31, 2017, there were no items of other comprehensive income. Therefore, no presentation of comprehensive income is required.

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.

In 2017, the Company transferred the right to sell a building to a special purpose entity to facilitate a potential Section 1031 exchange under the Internal Revenue Code of 1986, as amended (the "Code"), and the special purpose entity sold the building and retained the proceeds therefrom. To realize the tax deferral available under the Section 1031 exchange, the Company must complete the Section 1031 exchange, and take title to the to-be-exchanged building within 180 days of the disposition date. The Company has determined that this entity is a VIE, and the Company is the primary beneficiary. Therefore, the Company consolidates this entity. As of December 31, 2017, this VIE had total assets of $56.7 million, no significant liabilities, and no significant cash flows. In addition, the Company considers CPLP to be a VIE with the Company as the primary beneficiary.

Recently Issued Accounting Standards: In May 2014, the FASB issued ASU 2014-09 ("ASC 606"), "Revenue from Contracts with Customers." Under the new guidance, companies will recognize revenue when the seller satisfies a performance obligation, which would be when the buyer takes control of the good or service. ASU 2015-14 (collectively with ASU 2014-09, "ASC 606"), "Revenue from Contracts with Customers," was subsequently issued modifying the effective date to periods beginning after December 15, 2017, with early adoption permitted for periods beginning after December 15, 2016. The standard allows for either "full retrospective" adoption, meaning the standard is applied to all of the periods presented, or "modified retrospective" adoption, meaning the standard is applied only to the most recent period presented in the financial statements. The Company adopted this guidance using the “modified retrospective” method effective January 1, 2018. The classification of certain non-lease components of revenue from leases may be impacted by the new revenue standard upon the adoption of the new leasing standard beginning January 1, 2019 (see below). The Company has determined that the adoption of ASC 606 will not require any material adjustments to the consolidated financial statements but will result in additional disclosures related to disaggregation of revenue streams beginning in the first quarter of 2018.

In February 2016, the FASB issued ASU 2016-02, "Leases," which amends the existing standards for lease accounting by requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting and reporting. The new standard will require lessees to record a right-of-use asset and a lease liability for all leases with a term of greater than 12 months and classify such leases as either finance or operating leases based on the principle of whether or not the lease is effectively a financed purchase of the leased asset by the lessee. This classification will determine whether the lease expense is recognized based on an effective interest method (finance leases) or on a straight-line basis over the term of the lease (operating leases). Leases with a term of 12 months or less will be accounted for similar to existing guidance for operating leases. The new standard requires lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases, and operating leases. ASU 2016-02 supersedes previous leasing standards. The guidance is effective for the fiscal years beginning after December 15, 2018, with early adoption permitted. The Company expects to adopt this guidance using the "modified retrospective" method effective January 1, 2019, and is currently assessing the potential impact of adopting the new guidance.

In August 2016, the FASB issued ASU 2016-15, "Classification of Certain Cash Receipts and Cash Payments" ("ASU 2016-15") which updated ASC Topic 230, "Statement of Cash Flows." ASU 2016-15 clarifies guidance on the classification of certain cash receipts and payments in the statement of cash flows to reduce diversity in practice with respect to (i) debt prepayment or debt extinguishment costs, (ii) settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing, (iii) contingent consideration payments made after a business combination, (iv) proceeds from the settlement of insurance claims, (v) proceeds from the settlement of corporate-owned life insurance policies, including bank-owned life insurance policies, (vi) distributions received from equity method investees, (vii) beneficial interests in securitization transactions, and (viii) separately identifiable cash flows and application of the predominance principle. ASU 2016-15 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard in the fourth quarter of 2017 with retrospective application to the consolidated statements of cash flows. The Company elected to use the nature of distributions approach for distributions from its equity method investments, under which it classifies the distribution received on the basis of the nature of the activity that generated the distribution. The adoption of this new approach resulted in an increase in net cash provided by operating activities and a decrease in net cash provided by investing activities of $6.4 million and $2.9 million for the years ended December 31, 2016 and 2015, respectively.

In November 2016, the FASB issued ASU 2016-18, "Restricted Cash" ("ASU 2016-18") which updated ASC Topic 230, "Statement of Cash Flows." ASU 2016-18 requires companies to include restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company has early adopted this standard in the fourth quarter of 2017, which resulted in an increase in net cash provided by investing activities by $11.3 million for the year ended December 31, 2016 and a decrease in net cash provided by operating and investing activities by $263,000 and $475,000, respectively, for the year ended December 31, 2015.

Effective January 1, 2017, the Company adopted ASU 2016-09, "Improvements to Employee Share-Based Payment Accounting." Under this ASU, the additional paid-in capital pool is eliminated, and an entity recognizes all excess tax benefits and tax deficiencies as income tax expense or benefit in the income statement. This ASU also eliminated the requirement to defer recognition of an excess tax benefit until all benefits are realized through a reduction to taxes payable. In the first quarter of 2017, the Company changed the treatment of excess tax benefits as operating cash flows in the statement of cash flows. This ASU also stipulates that cash payments to tax authorities in connection with shares withheld to meet statutory tax withholding requirements be presented as a financing activity in the statement of cash flows. This ASU was adopted prospectively, prior periods have not been restated to conform to the current period presentation.

In January 2017, the FASB issued ASU 2017-01, "Clarifying the Definition of a Business," which provides a more narrow definition of a business to be used in determining the accounting treatment of an acquisition. As a result, many acquisitions that previously qualified as business combinations will be treated as asset acquisitions. For asset acquisitions, acquisition costs may be capitalized, and the purchase price may be allocated on a relative fair value basis. ASU 2017-01 is effective prospectively for the Company on January 1, 2018, with early adoption permitted. The Company adopted this standard in 2017 and expects that most of its future acquisitions will qualify as asset acquisitions.

In February 2017, the FASB issued ASU No. 2017-05, “Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets” (“ASU 2017-05”). ASU 2017-05 updates the definition of an “in substance nonfinancial asset” and clarifies the derecognition guidance for nonfinancial assets to conform with the new revenue recognition standard. Among other things, ASU 2017-05 requires companies to recognize 100% of the gain on the transfer of a nonfinancial asset to an entity in which it has a noncontrolling interest. ASU 2017-05 is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. The Company adopted this guidance using the "modified retrospective" method effective on January 1, 2018. As a result of the adoption of ASU 2017-05, the Company recorded a cumulative effect from change in accounting principle which credited distributions in excess of cumulative net income by $24.3 million. This cumulative effect adjustment resulted from the 2013 transfer of a wholly-owned property to an entity in which it had a noncontrolling interest.

In May 2017, FASB issued ASU 2017-09, "Scope of Modification Accounting," which amends the scope of modification accounting for share-based payment arrangements and provides guidance on the types of changes to the terms or conditions of share-based payment awards to which an entity would be required to apply modification accounting under ASC 718, "Compensation—Stock Compensation." This update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017, with early adoption permitted. The Company adopted this standard on January 1, 2018. Adoption of the standard did not have a material impact on the Company's financial statements.