Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies	3 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies	Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies GCP is engaged in the production and sale of specialty construction chemicals and specialty building materials through two operating segments. Specialty Construction Chemicals ("SCC") manufactures and markets concrete admixtures and cement additives. Specialty Building Materials ("SBM") manufactures and markets sheet and liquid membrane systems that protect structures from water, air and vapor penetration, fireproofing and other products designed to protect the building envelope. On July 3, 2017 (the "Closing Date"), GCP completed the sale of its Darex Packaging Technologies ("Darex") business to Henkel AG & Co. KGaA (“Henkel”) for $1.06 billion in cash. As discussed further below under "Discontinued Operations," the results of operations for Darex have been excluded from GCP's continuing operations and segment results for all periods presented. Basis of Presentation The accompanying unaudited Consolidated Financial Statements are presented on a consolidated basis and include all of the accounts and operations of GCP and its majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The financial statements reflect the financial position, results of operations and cash flows of GCP in accordance with generally accepted accounting principles in the United States ("GAAP") and with the instructions to Form 10-Q and Article 10 of SEC Regulation S-X for interim financial information. The interim financial statements presented herein are unaudited and should be read in conjunction with the audited Consolidated Financial Statements and notes thereto contained in GCP's Annual Report on Form 10-K filed with the SEC for the year ended December 31, 2018 (the "2018 Annual Report on Form 10-K"). The Consolidated Balance Sheet as of December 31, 2018 was derived from the audited annual consolidated financial statements as of the period then ended. Certain information and footnote disclosures typically included in GCP's annual consolidated financial statements have been condensed or omitted. The unaudited financial statements reflect all adjustments that, in the opinion of management, are necessary for a fair statement of the results of the interim periods presented. All such adjustments are of a normal recurring nature except for the impacts of adopting new accounting standards discussed below. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results of operations for the year ending December 31, 2019. Discontinued Operations On July 3, 2017, the Company completed the sale of Darex to Henkel. The agreement with Henkel governing the Disposition (the “Amended Purchase Agreement”) provides for a series of delayed closings in certain non-U.S. jurisdictions. In conjunction with this transaction and applicable GAAP, the assets and liabilities related to Darex in the applicable delayed close countries have been reclassified and reflected as held for sale in the accompanying unaudited Consolidated Balance Sheets as of March 31, 2019 and December 31, 2018, as discussed further in Note 18, "Discontinued Operations". Additionally, Darex results of operations and cash flows have been reclassified and reflected as "discontinued operations" in the accompanying unaudited Consolidated Statements of Operations and Consolidated Statements of Cash Flows for all periods presented. Unless otherwise noted, the information throughout the Notes to the accompanying unaudited Consolidated Financial Statements pertains only to the continuing operations of GCP. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited Consolidated Financial Statements, and the reported amounts of revenues and expenses for the periods presented. The Company assesses the estimates on an ongoing basis and records changes in estimates in the period they occur and become known. Actual results could differ from those estimates. GCP's accounting measurements that are most affected by management's estimates of future events are disclosed in its 2018 Annual Report on Form 10-K. There have been no significant changes to management's assumptions and estimates underlying those measurements as reported in these interim financial statements, except as discussed in Note 6, "Income Taxes". Cash and Cash Equivalents Cash and cash equivalents include cash on hand and highly liquid instruments with original maturities of three months or less that are readily convertible to known amounts of cash. The recorded amounts approximate fair value. As of March 31, 2019 and December 31, 2018, cash equivalents were approximately $106.8 million and $111.2 million, respectively, and were included within the "Cash and cash equivalents" in the accompanying unaudited Consolidated Balance Sheets. Cash equivalents consisted primarily of Bank Certificate of Deposits which were classified within Level 2 of the fair value hierarchy since they are not actively traded. Income Tax As a global enterprise, GCP is subject to a complex array of tax regulations and needs to make assessments of applicable tax law and judgments in estimating its ultimate income tax liability. Income tax expense and income tax balances represent GCP’s federal, state and foreign income taxes as an independent company. GCP files a U.S. consolidated income tax return, along with foreign and state corporate income tax filings, as required. Please refer to Note 6, "Income Taxes," for details regarding estimates used in accounting for income tax matters including unrecognized tax benefits. Foreign Currency Transactions and Translation Certain transactions of the Company and its subsidiaries are denominated in currencies other than their functional currency. Foreign currency exchange gains (losses) generated from the settlement and remeasurement of these transactions are recognized in earnings and presented within “Other income, net” in the Company’s accompanying unaudited Consolidated Statements of Operations. Net foreign currency transaction and remeasurement losses reflected in “Other income, net” were $0.3 million during each of the three months ended March 31, 2019 and 2018. GCP continues to account for its operations in Argentina as a highly inflationary economy. Effective July 1, 2018, the functional currency of the Company's subsidiary operating in Argentina became the U.S. dollar and all remeasurement adjustments after the effective date are reflected in GCP's results of operations in the accompanying unaudited Consolidated Statements of Operations. During the three months ended March 31, 2019, the Company incurred losses of $0.4 million related to the remeasurement of these monetary net assets which are included in "Other income, net" in the accompanying unaudited Consolidated Statements of Operations. The Argentina subsidiary's net sales were not material to the Company's consolidated net sales during the three months ended March 31, 2019 and its monetary net assets denominated in local currency were not material to GCP's consolidated total assets as of March 31, 2019 and December 31, 2018. Reclassifications Certain amounts in prior period financial statements have been reclassified to conform to the current period presentation. Such reclassifications have not materially affected previously reported amounts. Recently Adopted Accounting Standards Leases In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) whereas a lessee is required to recognize in the statement of financial position a lease liability related to making lease payments and a right-of-use asset representing its right to control the use of the underlying asset during the lease term, including optional payments that are reasonably certain to occur. The Company adopted Topic 842 effective January 1, 2019 and elected a transition option allowing it to forgo the application of comparative period presentation in the financial statements during the year of adoption. The accompanying unaudited Consolidated Financial Statements for the three months ended March 31, 2019 are presented in accordance with Topic 842, while the comparative periods have not been recast based on the new standard. The Company elected a package of practical expedients allowing to forgo the reassessment of expired or existing contracts to determine their lease classification, initial direct costs and whether any of such contracts represent or contain leases. The Company also made an accounting policy election to combine lease and non-lease components into a single lease component for each class of underlying assets for the arrangements in which GCP is a lessee, with the exception of a non-lease component related to inventory purchases. The Company separates purchases of raw materials, labor and certain other inventory-related costs from lease components based on their relative standalone values determined based on observable market information. The Company did not elect the hindsight practical expedient related to determining the lease term. The adoption of Topic 842 related to lease arrangements in which the Company is a lessee resulted in a recognition of operating lease right-of-use assets of $40.8 million and operating lease obligations of $40.9 million as of January 1, 2019. The adoption of Topic 842 did not result in significant accounting changes for finance leases which were not material as of March 31, 2019. The adoption of Topic 842 related to lease arrangements in which the Company is a lessee did not have a material impact on the Company's results of operations and cash flows during the three months ended March 31, 2019, as described in Note 5, "Lessee Arrangements". The Company generates revenue from certain sales arrangements within the SCC operating segment related to VERIFI^® and certain admixture contracts that include lease components, as discussed in Note 2 "Revenue from Lessor Arrangements and Contracts with Customers". Topic 842 provides a practical expedient which allows lessors to combine lease and non-lease components and account for them as one component if they have the same timing and pattern of transfer and the lease component is classified as an operating lease. The combined component is accounted for in accordance with Topic 842 if the lease component is predominant, and in accordance with Topic 606 if the non-lease component is predominant. Lessors are permitted to apply the practical expedient to all existing leases on a retrospective or prospective basis. The Company elected to apply the practical expedient prospectively based on a portfolio approach for certain classes of underlying assets. The Company does not include taxes (i.e. sales, use, value added or some excise taxes) in the contract consideration, variable lease payments or transaction price that are allocated among its products or services. The adoption of Topic 842 for the arrangements in which GCP is a lessor did not have a material impact on the Company's financial position, results of operations and cash flows during the three months ended March 31, 2019. Please refer to Note 2, "Revenue from Lessor Arrangements and Contracts with Customers" for further information on lease arrangements in which the Company is a lessor. Derivatives and Hedging In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815). The amendments in this update improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements by expanding and refining hedge accounting for both non-financial and financial risk components and aligning the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. GCP adopted the standard effective January 1, 2019. The adoption did not have a material impact on its financial position as of March 31, 2019 and results of operations and cash flows for the three months ended March 31, 2019. Recently Issued Accounting Standards Credit Losses In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments in this update introduce a new "expected loss" impairment model which applies to most financial assets measured at amortized cost and certain other instruments, including trade and other receivables, loans, held-to-maturity debt securities and other financial assets. Entities are required to estimate expected credit losses over the life of financial assets and record an allowance against the assets’ amortized cost basis to present them at the amount expected to be collected. Additionally, the guidance amends the impairment model for available for sale debt securities and requires entities to determine whether all or a portion of the unrealized loss on such debt security is a credit loss. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. Early adoption of the newly issued guidance is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. The standard should be applied as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. GCP expects to adopt the guidance effective January 1, 2020 and is currently evaluating the impact of this guidance on its financial position and results of operations. Other During the three months ended March 31, 2019, except as discussed above, there were no material changes to the Company's significant accounting and financial reporting policies from those reflected in the Annual Report on Form 10-K for the year ended December 31, 2018. For further information with regard to the Company’s Significant Accounting Policies, please refer to Note 1, "Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies," to the Company’s Consolidated Financial Statements included in the 2018 Annual Report on Form 10-K.

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies

GCP is engaged in the production and sale of specialty construction chemicals and specialty building materials through two operating segments. Specialty Construction Chemicals ("SCC") manufactures and markets concrete admixtures and cement additives. Specialty Building Materials ("SBM") manufactures and markets sheet and liquid membrane systems that protect structures from water, air and vapor penetration, fireproofing and other products designed to protect the building envelope.

On July 3, 2017 (the "Closing Date"), GCP completed the sale of its Darex Packaging Technologies ("Darex") business to Henkel AG & Co. KGaA (“Henkel”) for $1.06 billion in cash. As discussed further below under "Discontinued Operations," the results of operations for Darex have been excluded from GCP's continuing operations and segment results for all periods presented.

Basis of Presentation

The accompanying unaudited Consolidated Financial Statements are presented on a consolidated basis and include all of the accounts and operations of GCP and its majority-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The financial statements reflect the financial position, results of operations and cash flows of GCP in accordance with generally accepted accounting principles in the United States ("GAAP") and with the instructions to Form 10-Q and Article 10 of SEC Regulation S-X for interim financial information.

The interim financial statements presented herein are unaudited and should be read in conjunction with the audited Consolidated Financial Statements and notes thereto contained in GCP's Annual Report on Form 10-K filed with the SEC for the year ended December 31, 2018 (the "2018 Annual Report on Form 10-K"). The Consolidated Balance Sheet as of December 31, 2018 was derived from the audited annual consolidated financial statements as of the period then ended. Certain information and footnote disclosures typically included in GCP's annual consolidated financial statements have been condensed or omitted. The unaudited financial statements reflect all adjustments that, in the opinion of management, are necessary for a fair statement of the results of the interim periods presented. All such adjustments are of a normal recurring nature except for the impacts of adopting new accounting standards discussed below. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the results of operations for the year ending December 31, 2019.

Discontinued Operations

On July 3, 2017, the Company completed the sale of Darex to Henkel. The agreement with Henkel governing the Disposition (the “Amended Purchase Agreement”) provides for a series of delayed closings in certain non-U.S. jurisdictions. In conjunction with this transaction and applicable GAAP, the assets and liabilities related to Darex in the applicable delayed close countries have been reclassified and reflected as held for sale in the accompanying unaudited Consolidated Balance Sheets as of March 31, 2019 and December 31, 2018, as discussed further in Note 18, "Discontinued Operations". Additionally, Darex results of operations and cash flows have been reclassified and reflected as "discontinued operations" in the accompanying unaudited Consolidated Statements of Operations and Consolidated Statements of Cash Flows for all periods presented.

Unless otherwise noted, the information throughout the Notes to the accompanying unaudited Consolidated Financial Statements pertains only to the continuing operations of GCP.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited Consolidated Financial Statements, and the reported amounts of revenues and expenses for the periods presented. The Company assesses the estimates on an ongoing basis and records changes in estimates in the period they occur and become known. Actual results could differ from those estimates. GCP's accounting measurements that are most affected by management's estimates of future events are disclosed in its 2018 Annual Report on Form 10-K. There have been no significant changes to management's assumptions and estimates underlying those measurements as reported in these interim financial statements, except as discussed in Note 6, "Income Taxes".

Cash and Cash Equivalents

Cash and cash equivalents include cash on hand and highly liquid instruments with original maturities of three months or less that are readily convertible to known amounts of cash. The recorded amounts approximate fair value. As of March 31, 2019 and December 31, 2018, cash equivalents were approximately $106.8 million and $111.2 million, respectively, and were included within the "Cash and cash equivalents" in the accompanying unaudited Consolidated Balance Sheets. Cash equivalents consisted primarily of Bank Certificate of Deposits which were classified within Level 2 of the fair value hierarchy since they are not actively traded.

Income Tax

As a global enterprise, GCP is subject to a complex array of tax regulations and needs to make assessments of applicable tax law and judgments in estimating its ultimate income tax liability. Income tax expense and income tax balances represent GCP’s federal, state and foreign income taxes as an independent company. GCP files a U.S. consolidated income tax return, along with foreign and state corporate income tax filings, as required. Please refer to Note 6, "Income Taxes," for details regarding estimates used in accounting for income tax matters including unrecognized tax benefits.

Foreign Currency Transactions and Translation

Certain transactions of the Company and its subsidiaries are denominated in currencies other than their functional currency. Foreign currency exchange gains (losses) generated from the settlement and remeasurement of these transactions are recognized in earnings and presented within “Other income, net” in the Company’s accompanying unaudited Consolidated Statements of Operations. Net foreign currency transaction and remeasurement losses reflected in “Other income, net” were $0.3 million during each of the three months ended March 31, 2019 and 2018.

GCP continues to account for its operations in Argentina as a highly inflationary economy. Effective July 1, 2018, the functional currency of the Company's subsidiary operating in Argentina became the U.S. dollar and all remeasurement adjustments after the effective date are reflected in GCP's results of operations in the accompanying unaudited Consolidated Statements of Operations. During the three months ended March 31, 2019, the Company incurred losses of $0.4 million related to the remeasurement of these monetary net assets which are included in "Other income, net" in the accompanying unaudited Consolidated Statements of Operations. The Argentina subsidiary's net sales were not material to the Company's consolidated net sales during the three months ended March 31, 2019 and its monetary net assets denominated in local currency were not material to GCP's consolidated total assets as of March 31, 2019 and December 31, 2018.

Reclassifications

Certain amounts in prior period financial statements have been reclassified to conform to the current period presentation. Such reclassifications have not materially affected previously reported amounts.

Recently Adopted Accounting Standards

Leases

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) whereas a lessee is required to recognize in the statement of financial position a lease liability related to making lease payments and a right-of-use asset representing its right to control the use of the underlying asset during the lease term, including optional payments that are reasonably certain to occur. The Company adopted Topic 842 effective January 1, 2019 and elected a transition option allowing it to forgo the application of comparative period presentation in the financial statements during the year of adoption. The accompanying unaudited Consolidated Financial Statements for the three months ended March 31, 2019 are presented in accordance with Topic 842, while the comparative periods have not been recast based on the new standard. The Company elected a package of practical expedients allowing to forgo the reassessment of expired or existing contracts to determine their lease classification, initial direct costs and whether any of such contracts represent or contain leases. The Company also made an accounting policy election to combine lease and non-lease components into a single lease component for each class of underlying assets for the arrangements in which GCP is a lessee, with the exception of a non-lease component related to inventory purchases. The Company separates purchases of raw materials, labor and certain other inventory-related costs from lease components based on their relative standalone values determined based on observable market information. The Company did not elect the hindsight practical expedient related to determining the lease term.

The adoption of Topic 842 related to lease arrangements in which the Company is a lessee resulted in a recognition of operating lease right-of-use assets of $40.8 million and operating lease obligations of $40.9 million as of January 1, 2019. The adoption of Topic 842 did not result in significant accounting changes for finance leases which were not material as of March 31, 2019. The adoption of Topic 842 related to lease arrangements in which the Company is a lessee did not have a material impact on the Company's results of operations and cash flows during the three months ended March 31, 2019, as described in Note 5, "Lessee Arrangements".

The Company generates revenue from certain sales arrangements within the SCC operating segment related to VERIFI^® and certain admixture contracts that include lease components, as discussed in Note 2 "Revenue from Lessor Arrangements and Contracts with Customers". Topic 842 provides a practical expedient which allows lessors to combine lease and non-lease components and account for them as one component if they have the same timing and pattern of transfer and the lease component is classified as an operating lease. The combined component is accounted for in accordance with Topic 842 if the lease component is predominant, and in accordance with Topic 606 if the non-lease component is predominant. Lessors are permitted to apply the practical expedient to all existing leases on a retrospective or prospective basis. The Company elected to apply the practical expedient prospectively based on a portfolio approach for certain classes of underlying assets. The Company does not include taxes (i.e. sales, use, value added or some excise taxes) in the contract consideration, variable lease payments or transaction price that are allocated among its products or services. The adoption of Topic 842 for the arrangements in which GCP is a lessor did not have a material impact on the Company's financial position, results of operations and cash flows during the three months ended March 31, 2019. Please refer to Note 2, "Revenue from Lessor Arrangements and Contracts with Customers" for further information on lease arrangements in which the Company is a lessor.

Derivatives and Hedging

In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815). The amendments in this update improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements by expanding and refining hedge accounting for both non-financial and financial risk components and aligning the recognition and presentation of the effects of the hedging instrument and the hedged item in the financial statements. GCP adopted the standard effective January 1, 2019. The adoption did not have a material impact on its financial position as of March 31, 2019 and results of operations and cash flows for the three months ended March 31, 2019.

Recently Issued Accounting Standards

Credit Losses

In June 2016, the FASB issued ASU 2016-13, Financial Instruments- Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments in this update introduce a new "expected loss" impairment model which applies to most financial assets measured at amortized cost and certain other instruments, including trade and other receivables, loans, held-to-maturity debt securities and other financial assets. Entities are required to estimate expected credit losses over the life of financial assets and record an allowance against the assets’ amortized cost basis to present them at the amount expected to be collected. Additionally, the guidance amends the impairment model for available for sale debt securities and requires entities to determine whether all or a portion of the unrealized loss on such debt security is a credit loss. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. Early adoption of the newly issued guidance is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. The standard should be applied as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. GCP expects to adopt the guidance effective January 1, 2020 and is currently evaluating the impact of this guidance on its financial position and results of operations.

Other

During the three months ended March 31, 2019, except as discussed above, there were no material changes to the Company's significant accounting and financial reporting policies from those reflected in the Annual Report on Form 10-K for the year ended December 31, 2018. For further information with regard to the Company’s Significant Accounting Policies, please refer to Note 1, "Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies," to the Company’s Consolidated Financial Statements included in the 2018 Annual Report on Form 10-K.