GCP Applied (GCP) 10-Q 8 Aug 19 2019 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2019	Aug. 01, 2019
Cover page.
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	1-137533
Entity Registrant Name	GCP Applied Technologies Inc.
Entity Central Index Key	0001644440
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-3936076
Entity Address, Address Line One	62 Whittemore Avenue
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02140-1623
City Area Code	617
Local Phone Number	876-1400
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	GCP
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		72,671,410

Consolidated Statements of Oper

Consolidated Statements of Operations (unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales		$ 262.2	$ 302.8	$ 488.3	$ 553
Cost of goods sold		163.2	191.1	307.1	353.8
Gross profit		99	111.7	181.2	199.2
Selling, general and administrative expenses		71.4	77.6	140.4	152.5
Research and development expenses		4.6	5.3	9.3	10.2
Interest expense and related financing costs		5.7	66.7	11.6	80.5
Repositioning expenses		5.8	1.2	11.2	2.1
Restructuring expenses and asset impairments		4.4	(0.6)	5	(1.1)
Other income, net		(1.7)	(4.1)	(3.5)	(10.4)
Total costs and expenses		90.2	146.1	174	233.8
Income (loss) from continuing operations before income taxes		8.8	(34.4)	7.2	(34.6)
(Provision for) benefit from income taxes		(5.7)	5.3	10.7	(8.2)
Income (loss) from continuing operations		3.1	(29.1)	17.9	(42.8)
(Loss) income from discontinued operations, net of income taxes		(0.5)	1.3	6.3	8.5
Net income (loss)		2.6	(27.8)	24.2	(34.3)
Less: Net income attributable to noncontrolling interests		0	(0.1)	(0.2)	(0.2)
Net income (loss) attributable to GCP shareholders		2.6	(27.9)	24	(34.5)
Amounts Attributable to GCP Shareholders:
Income (loss) from continuing operations attributable to GCP shareholders		3.1	(29.2)	17.7	(43)
(Loss) income from discontinued operations, net of income taxes		$ (0.5)	$ 1.3	$ 6.3	$ 8.5
Basic earnings (loss) per share:
Income (loss) from continuing operations attributable to GCP shareholders (in usd per share)		$ 0.04	$ (0.40)	$ 0.24	$ (0.60)
(Loss) income from discontinued operations, net of income taxes (in usd per share)		(0.01)	0.02	0.09	0.12
Net income (loss) attributable to GCP shareholders (in usd per share)	[1]	$ 0.04	$ (0.39)	$ 0.33	$ (0.48)
Weighted average number of basic shares (in shares)		72.6	72.1	72.5	72
Diluted earnings (loss) per share:
Income (loss) from continuing operations attributable to GCP shareholders (in dollars per share)	[2]	$ 0.04	$ (0.40)	$ 0.24	$ (0.60)
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	[2]	(0.01)	0.02	0.09	0.12
Net income (loss) attributable to GCP shareholders (in dollars per share)	[1],[2]	$ 0.04	$ (0.39)	$ 0.33	$ (0.48)
Weighted average number of diluted shares (in shares)	[2]	73	72.1	72.9	72
[1]	Amounts may not sum due to rounding.
[2]	Dilutive effect is only applicable to the periods during which GCP generated net income from continuing operations.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2.6	$ (27.8)	$ 24.2	$ (34.3)
Other comprehensive loss:
Defined benefit pension and other postretirement plans, net of income taxes	0	(0.6)	0	(0.6)
Currency translation adjustments	(3.9)	(32.5)	(0.6)	(18.2)
Gain (loss) from hedging activities, net of income taxes	0	0.1	(0.1)	0.1
Total other comprehensive loss	(3.9)	(33)	(0.7)	(18.7)
Comprehensive (loss) income	(1.3)	(60.8)	23.5	(53)
Less: Comprehensive income attributable to noncontrolling interests	0	(0.1)	(0.2)	(0.2)
Comprehensive (loss) income attributable to GCP shareholders	$ (1.3)	$ (60.9)	$ 23.3	$ (53.2)

Consolidated Balance Sheets (un

Consolidated Balance Sheets (unaudited) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Current Assets
Cash and cash equivalents	$ 279.8	$ 326.1
Trade accounts receivable (including allowances of $6.3 million and $5.8 million, respectively)	188.4	198.6
Inventories, net	117.1	110.5
Other current assets	44	44.6
Current assets held for sale	0	3.4
Total Current Assets	629.3	683.2
Properties and equipment, net	235.3	225.1
Operating lease right-of-use assets	36.3	0
Goodwill	207.4	207.9
Technology and other intangible assets, net	84.7	89
Deferred income taxes	26.5	25.5
Overfunded defined benefit pension plans	22.3	22.5
Other assets	28.1	28
Non-current assets held for sale	0.5	0.7
Total Assets	1,270.4	1,281.9
Current Liabilities
Debt payable within one year	3	10.6
Operating lease obligations payable within one year	9.3	0
Accounts payable	104	121.4
Other current liabilities	105.2	145.5
Total Current Liabilities	221.5	277.5
Debt payable after one year	346.1	346.1
Income taxes payable	41.1	37.7
Deferred income taxes	12.2	12.4
Operating lease obligations	27.3	0
Unrecognized tax benefits	43.6	62.8
Underfunded and unfunded defined benefit pension plans	50.5	48.1
Other liabilities	15.8	15.5
Non-current liabilities held for sale	0	0.4
Total Liabilities	758.1	800.5
Commitments and Contingencies - Note 10
Stockholders' Equity
Preferred stock, par value $0.01; authorized: 10,000,000 and 0 shares, respectively; no shares issued or outstanding	0	0
Common stock issued, par value $0.01; 300,000,000 shares authorized; outstanding: 72,670,366 and 72,176,324, respectively	0.7	0.7
Paid-in capital	50.2	39.6
Accumulated earnings	587.9	563.9
Accumulated other comprehensive loss	(120.7)	(120)
Treasury stock	(8)	(4.8)
Total GCP's Shareholders' Equity	510.1	479.4
Noncontrolling interests	2.2	2
Total Stockholders' Equity	512.3	481.4
Total Liabilities and Stockholders' Equity	$ 1,270.4	$ 1,281.9

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance	$ 6.3	$ 5.8
Preferred stock, par value (in usd per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	10,000,000	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	300,000,000	300,000,000
Common stock, outstanding (in shares)	72,670,366	72,176,324

Consolidated Statements of Equi

Consolidated Statements of Equity (unaudited) - USD ($) $ in Millions		Total	Common Stock	Treasury Stock		Additional Paid-in Capital	Accumulated Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Treasury Stock, Shares				100,000
Beginning balance (in shares) at Dec. 31, 2017			71,900,000
Beginning balance at Dec. 31, 2017		$ 492	$ 0.7	$ (3.4)		$ 29.9	$ 548.7	$ (85.7)	$ 1.8
Increase (Decrease) in Stockholders' Equity
Net income (loss)		(34.3)					(34.5)		0.2
Issuance of common stock in connection with stock plans (in shares)	[1]		200,000
Issuance of common stock in connection with stock plans	[1]	0
Share-based compensation		5.8				5.8
Exercise of stock options (in shares)			300,000
Exercise of stock options		$ 5.1				5.1
Share repurchases (in shares)		45,000		100,000	[2]
Share repurchases	[2]	$ (1.3)		$ (1.3)
Other comprehensive income (loss)		(18.7)						(18.7)
Ending balance (in shares) at Jun. 30, 2018			72,400,000
Ending balance at Jun. 30, 2018		448.6	$ 0.7	$ (4.7)		40.8	514.2	(104.4)	2
Treasury Stock, Shares				200,000
Beginning balance (in shares) at Mar. 31, 2018			72,200,000
Beginning balance at Mar. 31, 2018		504.5	$ 0.7	$ (4.1)		35.3	542.1	(71.4)	1.9
Increase (Decrease) in Stockholders' Equity
Net income (loss)		(27.8)					(27.9)		0.1
Issuance of common stock in connection with stock plans (in shares)			100,000
Share-based compensation		3.9				3.9
Exercise of stock options (in shares)			100,000
Exercise of stock options		$ 1.6				1.6
Share repurchases (in shares)		22,000
Share repurchases		$ (0.6)		(0.6)
Other comprehensive income (loss)		(33)						(33)
Ending balance (in shares) at Jun. 30, 2018			72,400,000
Ending balance at Jun. 30, 2018		448.6	$ 0.7	$ (4.7)		40.8	514.2	(104.4)	2
Treasury Stock, Shares				200,000
Treasury Stock, Shares				200,000
Beginning balance (in shares) at Dec. 31, 2018			72,400,000
Beginning balance at Dec. 31, 2018		481.4	$ 0.7	$ (4.8)		39.6	563.9	(120)	2
Increase (Decrease) in Stockholders' Equity
Net income (loss)		24.2					24		0.2
Issuance of common stock in connection with stock plans (in shares)	[1]		300,000
Issuance of common stock in connection with stock plans	[1]	0
Share-based compensation		5.6				5.6
Exercise of stock options (in shares)			300,000
Exercise of stock options		$ 5				5
Share repurchases (in shares)		125,700		100,000	[2]
Share repurchases	[2]	$ (3.2)		$ (3.2)
Other comprehensive income (loss)		(0.7)						(0.7)
Ending balance (in shares) at Jun. 30, 2019			73,000,000
Ending balance at Jun. 30, 2019		512.3	$ 0.7	$ (8)		50.2	587.9	(120.7)	2.2
Treasury Stock, Shares				300,000
Beginning balance (in shares) at Mar. 31, 2019			72,900,000
Beginning balance at Mar. 31, 2019		508	$ 0.7	$ (8)		44.6	585.3	(116.8)	2.2
Increase (Decrease) in Stockholders' Equity
Net income (loss)		2.6					2.6
Share-based compensation		3.9				3.9
Exercise of stock options (in shares)			100,000
Exercise of stock options		$ 1.7				1.7
Share repurchases (in shares)		300
Share repurchases		$ 0
Other comprehensive income (loss)		(3.9)						(3.9)
Ending balance (in shares) at Jun. 30, 2019			73,000,000
Ending balance at Jun. 30, 2019		$ 512.3	$ 0.7	$ (8)		$ 50.2	$ 587.9	$ (120.7)	$ 2.2
Treasury Stock, Shares				300,000
[1]	The par value of shares issued is not included in the table due to rounding.
[2]	During the six months ended June 30, 2019 and 2018, GCP withheld and retained approximately 125,700 shares and 45,000 shares, respectively, of Company common stock in a non-cash transaction with a cost of $3.2 million and $1.3 million , respectively, in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the six months ended June 30, 2019 and 2018, cash payments for such tax withholding obligations were $3.2 million and $1.3 million , respectively.

Consolidated Statements of Eq_2

Consolidated Statements of Equity (unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018
Statement of Stockholders' Equity [Abstract]
Share repurchases (in shares)	300	22,000	125,700		45,000
Share repurchases	$ 0	$ 0.6	$ 3.2	[1]	$ 1.3	[1]
Cash payments for tax withholding obligations		$ 0.6	$ 3.2		$ 1.3
[1]	During the six months ended June 30, 2019 and 2018, GCP withheld and retained approximately 125,700 shares and 45,000 shares, respectively, of Company common stock in a non-cash transaction with a cost of $3.2 million and $1.3 million , respectively, in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the six months ended June 30, 2019 and 2018, cash payments for such tax withholding obligations were $3.2 million and $1.3 million , respectively.

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES
Net income (loss)	$ 24.2	$ (34.3)
Less: Income from discontinued operations	6.3	8.5
Income (loss) from continuing operations	17.9	(42.8)
Reconciliation to net cash used in operating activities:
Depreciation and amortization	21.1	20.8
Amortization of debt discount and financing costs	0.7	0.9
Stock-based compensation expense	5	5.3
Unrealized gain on foreign currency	0	(0.8)
Gain on termination and curtailment of pension and other postretirement benefit plans	0	(0.1)
Deferred income taxes	(15.5)	(6)
Loss on debt refinancing	0	59.8
Gain on disposal of property and equipment	(0.2)	(1.1)
Changes in assets and liabilities, excluding effect of currency translation:
Trade accounts receivable	9.5	(3.3)
Inventories	(6.8)	(10.7)
Accounts payable	(17.6)	5.2
Pension assets and liabilities, net	2.5	(0.4)
Other assets and liabilities, net	(17.3)	(36.4)
Net cash used in operating activities from continuing operations	(0.7)	(9.6)
Net cash used in operating activities from discontinued operations	(12.4)	(124.9)
Net cash used in operating activities	(13.1)	(134.5)
INVESTING ACTIVITIES
Capital expenditures	(27.7)	(27.6)
Businesses acquired, net of cash acquired	0	(29.8)
Other investing activities	0.5	(2.8)
Net cash used in investing activities from continuing operations	(27.2)	(60.2)
Net cash used in investing activities from discontinued operations	(0.4)	(0.2)
Net cash used in investing activities	(27.6)	(60.4)
FINANCING ACTIVITIES
Borrowings under credit arrangements	0	53.5
Repayments under credit arrangements	(7.6)	(58.4)
Proceeds from issuance of long term note obligations	0	350
Payments on finance lease obligations	(0.4)	0
Repayments of long term note obligations	0	(578.3)
Cash paid for debt financing costs	0	(6.9)
Payments of tax withholding obligations related to employee equity awards	(3.2)	(1.3)
Proceeds from exercise of stock options	5	5.1
Other financing activities	0	(0.2)
Net cash used in financing activities	(6.2)	(236.5)
Effect of currency exchange rate changes on cash and cash equivalents	0.6	(0.8)
Decrease in cash and cash equivalents	(46.3)	(432.2)
Cash and cash equivalents, beginning of period	326.1	721.5
Cash and cash equivalents, end of period	$ 279.8	$ 289.3

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies	6 Months Ended
	Jun. 30, 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 and six months ended June 30, 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 June 30, 2019 and December 31, 2018, as discussed further in Note 19, "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 7, "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 are presented at amortized cost and approximate fair value. Amounts are included within the "Cash and cash equivalents" in the accompanying unaudited Consolidated Balance Sheets. 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 7, "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 gains (losses) reflected in “Other income, net” were immaterial for the three and six months ended June 30, 2019. Foreign currency transaction and remeasurement losses were $0.4 million and $0.7 million , respectively, for the three and six months ended June 30, 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. The gains (losses) related to the remeasurement of these monetary net assets are included in "Other income, net" in the accompanying unaudited Consolidated Statements of Operations, and were immaterial for the three and six months ended June 30, 2019. The Argentina subsidiary's net sales were not material to the Company's consolidated net sales during the three and six months ended June 30, 2019 and its monetary net assets denominated in local currency were not material to GCP's consolidated total assets as of June 30, 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 and six months ended June 30, 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 it 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 June 30, 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 during the three and six months ended June 30, 2019 and cash flows during the six months ended June 30, 2019, as described in Note 6, "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 as of June 30, 2019, results of operations during the three and six months ended June 30, 2019, and cash flows during the six months ended June 30, 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 standard did not have a material impact on the Company's financial position, results of operations and cash flows upon adoption. 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 at inception 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 related to 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 and six months ended June 30, 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.

Revenue from Lessor Arrangement

Revenue from Lessor Arrangements and Contracts with Customers	6 Months Ended
	Jun. 30, 2019
Revenues [Abstract]
Revenue from Lessor Arrangements and Contracts with Customers	Revenue from Lessor Arrangements and Contracts with Customers Short-Term Arrangements The majority of the Company’s revenue is generated from short-term arrangements associated with the production and sale of concrete admixtures and cement additives within its SCC operating segment, as well as sheet and liquid membrane systems and other specialty products designed to protect the building envelope within its SBM operating segment. For further information on revenue recognition related to product sale arrangements, please refer to Note 2, "Revenue from Contracts with Customers", to the Company’s Consolidated Financial Statements included in the 2018 Annual Report on Form 10-K. The Company generates revenue from short-term arrangements within its SCC operating segment which involve selling concrete admixtures and providing dispensers to customers. GCP has determined at contract inception that the dispensers represent a lease since the customer has the right to control the use of the dispensers over a period of time in exchange for consideration. The Company has elected to apply the practical expedient to the dispenser asset class and combine lease and non-lease components related to dispenser maintenance services. Such components will be accounted for as one component since 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 since the lease component is predominant. Concrete admixtures sold as a part of these arrangements represent a separate non-lease component which does not get combined with the lease component since it does not meet the defined criteria. The Company allocates contract consideration between the lease component and concrete admixtures based on their relative stand-alone selling prices determined based on a cost plus a reasonable margin approach for the lease component and standalone selling prices for the concrete admixtures. The Company recognizes revenue for the concrete admixtures at a point of time when the control is transferred to the customer. The lease component is considered to have a short non-cancelable lease term which is generally thirty days or less and classified as an operating lease. The Company recognizes revenue for the lease component on a straight line basis over the lease term. GCP records dispensers as fixed assets and depreciates them over their estimated useful life of 10 years . Long-Term Arrangements The Company generates revenue from long-term arrangements within its SCC operating segment, which generally consist of VERIFI ® and Ductilcrete sales arrangements. VERIFI ® sales arrangements involve installing equipment on the customers’ trucks and at their plants, as well as performing slump management and truck location tracking services. The Company has determined at contract inception that the installed equipment represents a lease since the customer has the right to control the equipment use over a period of time in exchange for consideration. Slump management and truck location tracking services represent a non-lease component. The Company classifies these leases as operating and accounts for the lease and the non-lease components separately since it did not elect to apply the practical expedient to combine lease and non-lease components for the VERIFI ® equipment asset class. Contract consideration for VERIFI ® sales arrangements consists primarily of fixed installation fees and other fixed payments and gets allocated between the lease and non-lease components based on valuation techniques that estimate a relative stand-alone selling price of each component. The Company recognizes revenue for the lease component on a straight line basis over the lease term. VERIFI ® equipment is recorded within "Properties and equipment, net" in the accompanying unaudited Consolidated Balance Sheets and depreciated over an estimated useful life of 7 years . The services included within the non-lease component represent the Company’s stand-ready promise to perform a series of daily distinct services, which is combined into a single performance obligation. The Company recognizes revenue associated with such services over time since the customer simultaneously receives and consumes the benefits provided by such services. The transaction price in a VERIFI ® sales arrangement consists of fixed installation fees and other fixed payments included in the contract consideration, as well as slump management fees which are dependent on the quantity of material poured and represent variable consideration. The Company excludes variable consideration from the contract consideration at lease commencement and allocates it between the lease and non-lease components based on their relative stand-alone selling prices. Revenue related to variable consideration for the lease and non-lease components is recorded at the time of the transfer of services to its customers, which is constrained by the amount for which a significant revenue reversal is not probable to occur. Revenue generated from VERIFI ® sales arrangements represented less than 10% of the Company's consolidated revenue during the three and six months ended June 30, 2019 and 2018. Revenue generated from Ductilcrete sales arrangements also represented less than 10% of the Company's consolidated revenue during the three and six months ended June 30, 2019 and 2018. For further information on revenue recognition related to these arrangements, please refer to Note 2, "Revenue from Contracts with Customers", to the Company’s Consolidated Financial Statements included in the 2018 Annual Report on Form 10-K. The Company’s revenue is principally recognized as goods and services are delivered and performance obligations are satisfied upon delivery. The Company has certain long-term arrangements resulting in remaining obligations for which the work has not been performed or has been partially performed. As of June 30, 2019 , the aggregate amount of the transaction price allocated to remaining performance obligations was $5.2 million , including the estimated transaction price to be earned as revenue over the remaining term of these contracts, which is generally one to five years . Lease elements within sales arrangements Certain sales arrangements within the SCC operating segment related to VERIFI ® and certain admixture contracts include lease components, as discussed above. The following table summarizes the revenue recognized for these sales arrangements for the three and six months ended June 30, 2019 and 2018 and distinguishes between the lease and non-lease components: Three Months Ended June 30, Six Months Ended June 30, in millions 2019 2018 2019 2018 Lease revenue (1): Lease payments revenue $ 6.8 $ 6.8 $ 13.2 $ 13.1 Variable lease revenue 1.9 1.8 3.4 3.2 Total lease revenue $ 8.7 $ 8.6 $ 16.6 $ 16.3 Service revenue (2): Fixed fee revenue $ — $ — $ — $ 0.1 Variable fee revenue 1.2 1.1 2.2 2.0 Total service revenue $ 1.2 $ 1.1 $ 2.2 $ 2.1 Total revenue $ 9.9 $ 9.7 $ 18.8 $ 18.4 ________________________________ (1) Lease revenue consists of dispensers lease revenue, as well as an allocated portion of VERIFI ® fixed fees and variable slump management fees. Lease revenue is included within "Net Sales" in the accompanying unaudited Consolidated Statements of Operations. (2) Service revenue consists of an allocated portion of VERIFI ® fixed fees and variable slump management fees. Service revenue is included within "Net Sales" in the accompanying unaudited Consolidated Statements of Operations. As of June 30, 2019 and December 31, 2018, the Company’s total trade accounts receivable balance was $188.4 million and $198.6 million , respectively, of which $5.5 million and $4.7 million , respectively, was related to trade accounts receivable associated with lease revenue generated from certain SCC contracts. The future minimum lease payments receivable under the operating leases were not material as of June 30, 2019. Other revenue considerations Contract assets consist of unbilled amounts typically resulting from sales under long-term contracts when the revenue recognized exceeds the amount billed to the customer. Contract liabilities consist of advance customer payments and billings for revenue not meeting the criteria to be recognized and/or in excess of costs incurred. The Company’s contract assets and liabilities resulting from its contracts in the SCC or SBM operating segments were not material as of June 30, 2019 and December 31, 2018. Additionally, the amounts recorded in the accompanying unaudited Consolidated Statements of Operations during the three and six months ended June 30, 2019 and 2018 related to changes in the contract assets and liabilities were not material.

Inventories, net

Inventories, net	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net The following is a summary of inventories presented in the accompanying unaudited Consolidated Balance Sheets at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Raw materials $ 49.3 $ 46.0 In process 5.0 4.6 Finished products and other 62.8 59.9 Total inventories, net $ 117.1 $ 110.5 The "Finished products and other" category presented in the table above includes "other" inventories, which consist of finished products purchased rather than produced by GCP of $13.4 million and $12.9 million , respectively, as of June 30, 2019 and December 31, 2018

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	Derivative Instruments The Company uses derivative instruments to partially offset its business exposure to foreign currency risk on net investments in certain foreign subsidiaries. The Company may choose not to hedge certain exposures for a variety of reasons including, but not limited to, accounting considerations or significant economic cost of hedging particular exposures. To protect the net investment in a foreign operation from fluctuations in foreign currency exchange rates, the Company may enter into foreign currency forward contracts to offset a portion of the changes in the carrying amounts of these investments due to fluctuations in foreign currency exchange rates. During the three months ended June 30, 2019, the Company entered into four forward contracts with an aggregate notional amount of € 40.0 million to hedge foreign currency exposure on net investments in certain of its European subsidiaries whose functional currency is the Euro. These forward contracts are designated as hedging instruments and recognized at fair value as assets or liabilities in the accompanying unaudited Consolidated Balance Sheets. Each contract has a notional amount of € 10.0 million and matures annually starting on June 15, 2020 through June 13, 2023. The contracts will settle in US Dollars upon maturity. The forward contracts are designated and qualify as net investment hedges. The Company made an accounting policy election to assess effectiveness for its net investment hedges based on the spot rate method. With the spot rate method, changes in hedge fair values attributable to the differences between the forward rate and the spot rate at inception are excluded from the effectiveness assessment. The initial value of such amounts is measured at contract inception and recognized in earnings within “Other income, net” in the Company’s accompanying unaudited Consolidated Statements of Operations, consistent with the Company's accounting policy election to amortize it on a straight-line basis over the hedging instruments' contractual term. The change in the fair value of the net investment hedges included in their effectiveness assessment is recognized within "Cumulative Translation Adjustments" of Other Comprehensive Loss until the hedged net investments in foreign operations are sold or substantially liquidated. The following table summarizes the fair value of the Company’s derivative instruments designated as net investment hedges as of June 30, 2019: (In millions) As of June 30, 2019 Derivative liabilities (1) : Foreign exchange forward contracts $ 0.3 __________________________ (1) The fair value of derivative instruments is measured based on expected future cash flows discounted at market interest rates using observable market inputs and classified as Level 2 within the fair value hierarchy. Fair value of derivative liabilities is recorded within "Other Current Liabilities" and "Other Liabilities" in the accompanying unaudited Consolidated Balance Sheets. The following table summarizes the amounts recorded in the Company's accompanying unaudited Consolidated Statements of Operations and Consolidated Statements of Comprehensive (Loss) Income related to forward contracts designated as net investment hedges for the three months ended June 30, 2019: (In millions) Three Months Ended June 30, 2019 "Other Income, net" Cumulative Translation Adjustments (1) Gains (losses) on foreign exchange forward contracts $ 0.1 $ (0.2 ) __________________________ (1) The amount is presented net of tax benefit of $0.1 million .

Debt and Other Borrowings

Debt and Other Borrowings	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt and Other Borrowings	Debt and Other Borrowings Components of Debt and Other Borrowings The following is a summary of obligations under senior notes and other borrowings at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, 5.5% Senior Notes due in 2026, net of unamortized debt issuance costs of $4.1 million and $4.4 million, respectively, at June 30, 2019 and December 31, 2018 $ 345.9 $ 345.6 Revolving credit facility due 2023 (1) — — Other borrowings (2) 3.2 11.1 Total debt 349.1 356.7 Less: debt payable within one year 3.0 10.6 Debt payable after one year $ 346.1 $ 346.1 Weighted average interest rates on total debt obligations 5.5 % 5.7 % __________________________ (1) Represents borrowings under the Revolving Credit Facility with an aggregate available principal amount of $350.0 million as of June 30, 2019 and December 31, 2018 . (2) Represents borrowings of $1.9 million and $9.4 million , respectively, under various lines of credit and other borrowings, primarily by non-U.S. subsidiaries, as well as $1.3 million and $1.7 million , respectively, of finance lease obligations. The principal maturities of debt obligations outstanding, net of debt issuance costs, were as follows at June 30, 2019 : (In millions) Year ending December 31, Amount 2019 $ 2.7 2020 0.5 2021 — 2022 — 2023 — Thereafter 345.9 Total debt $ 349.1 5.5% Senior Notes GCP's outstanding 5.5% Senior Notes have an aggregate principal amount of $350.0 million maturing on April 15, 2026. Interest on the 5.5% Senior Notes is payable semi-annually in arrears on April 15 and October 15 of each year. The Company made an interest payment of $9.6 million on April 15, 2019. The Indenture contains certain customary affirmative and negative covenants and events of default, as described in Note 6, "Debt and Other Borrowings," to the Company's Consolidated Financial Statements included in the 2018 Annual Report in the Form 10-K. The Company was in compliance with all covenants and conditions under the Indenture as of June 30, 2019 . There are no events of default under the Indenture as of June 30, 2019 . Credit Agreement As of June 30, 2019 and December 31, 2018, there were no outstanding borrowings on the Revolving Credit Facility and approximately $5.0 million in outstanding letters of credit which resulted in available credit of $345.0 million . There were no interest payments on the Revolving Credit Facility during the three and six months ended June 30, 2019 . The interest rate per annum applicable to the Revolving Credit Facility is equal to, at GCP’s option, either: (i) a base rate plus a margin ranging from 0.5% to 1.0% , or (ii) LIBOR plus a margin ranging from 1.5% to 2.0% , based upon the total leverage ratio of GCP and its restricted subsidiaries in both scenarios. The Credit Agreement contains conditions that would require mandatory principal payments in advance of the maturity date of the Revolving Credit Facility, as well as certain customary affirmative and negative covenants and events of default, as described in Note 6, "Debt and Other Borrowings," to the Company's Consolidated Financial Statements included in the 2018 Annual Report in the Form 10-K. The Company was in compliance with all covenant terms as of June 30, 2019 . There are no events of default as of June 30, 2019 . Debt Issuance Costs GCP recognizes expenses directly associated with obtaining the Revolving Credit Facility as debt issuance costs which are presented within "Other assets" in the accompanying unaudited Consolidated Balance Sheets. Such costs are amortized over the term of the Revolving Credit Facility and included in “Interest expense and related financing costs” in the accompanying unaudited Consolidated Statements of Operations. As of June 30, 2019 and December 31, 2018 , the remaining unamortized debt issuance costs related to the Revolving Credit Facility were $3.6 million and $4.1 million , respectively. Debt Fair Value The carrying amount and fair value of GCP's debt and other borrowings were as follows: June 30, 2019 December 31, 2018 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value 5.5% Senior Notes due in 2026 $ 345.9 $ 355.6 $ 345.6 $ 344.2 Other borrowings 3.2 3.2 11.1 11.1 Total debt $ 349.1 $ 358.8 $ 356.7 $ 355.3 Fair value is determined based on Level 2 inputs, including expected future cash flows (discounted at market interest rates), estimated current market prices, and quotes from financial institutions. The increase in fair value compared to the carrying value as of June 30, 2019 , was due to a decrease in interest rates.

Lessee Arrangements

Lessee Arrangements	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lessee Arrangements	Lessee Arrangements The Company determines at contract inception whether the contract represents or contains a lease and conveys the right to control the use of an identified asset over a period of time in exchange for consideration. For leases with terms greater than 12 months, the Company recognizes right-of-use assets and lease obligations at the lease commencement date based on a present value of lease payments over the lease term. Lease payments included in the measurement of right-of-use assets and lease obligations consist of: (i) fixed payments, including periodic rent increases and excluding any lease incentives paid or payable to the Company by a lessor, and (ii) certain variable payments that depend on an index or a market rate measured on the commencement date. The Company estimates its incremental borrowing rate based on the remaining lease term and remaining lease payments, as well as other information available at lease commencement since a readily determinable implicit rate is not provided in the Company's leases. The Company has elected to utilize a portfolio approach as it pertains to the application of the appropriate discount rates to its portfolios of leases. The weighted average discount rate for operating leases was 5.21% as of June 30, 2019 . Right-of-use assets for operating leases are initially measured on the lease commencement date and include any initial direct costs incurred, as well as lease obligation amounts, net of any lease incentives received from a lessor. Lease expense for operating leases is recognized on a straight-line basis over the lease term which includes: (i) a non-cancelable term during which the Company has a right to use an underlying asset, (ii) renewal options that extend the lease, are in the control of the lessor and are reasonably certain to be exercised, and (iii) options to terminate the lease before the end of its non-cancelable term that are not reasonably certain to be exercised. Variable payments that are excluded from the measurement of right-of-use assets and lease obligations consist primarily of non-lease related services, the Company's proportionate share of operating expenses for the leased facilities and certain payments related to excess mileage and usage charges for the leased vehicles and equipment. Such variable payments are recognized as lease expense in the results of operations when the obligation is incurred. The Company does not record right-of-use assets and lease obligations for leases with an initial term of 12 months or less and recognizes lease expense on a straight-line basis over the lease term. Finance leases are included in "Property and equipment, net", "Debt payable within one year" and "Debt payable after one year" in the accompanying unaudited Consolidated Balance Sheets and are not material at June 30, 2019 and December 31, 2018. The Company leases manufacturing and office facilities, as well as certain vehicles and equipment under operating leases. Certain manufacturing facilities are leased under land and building lease arrangements where lease terms as of June 30, 2019 consist of a remaining non-cancelable lease term of up to 8.2 years and renewal options that are reasonably certain to be exercised for an additional term of up to 32.0 years . The weighted average remaining lease term for operating leases was 15.0 years as of June 30, 2019 . The following table summarizes components of lease expense for the three and six months ended June 30, 2019 : (In millions) Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense $ 3.1 $ 6.4 Variable lease expense 1.3 2.5 Short-term lease expense 0.5 0.9 Total lease expense $ 4.9 $ 9.8 The following table summarizes lease liability maturities as of June 30, 2019 : (In millions) Year ending December 31, Amount 2019 $ 5.9 2020 8.9 2021 5.3 2022 3.0 2023 2.1 Thereafter 26.7 Total undiscounted lease payments 51.9 Less: imputed interest (15.3 ) Present value of lease payments 36.6 Less: operating lease obligations payable within one year (9.3 ) Long-term operating lease obligations $ 27.3 The following table summarizes supplemental cash flow information related to leases during the six months ended June 30, 2019 : (In millions) Amount Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 6.4 Operating lease right of use assets obtained in exchange for new lease obligations: Upon adoption of Topic 842 $ 40.8 During the six months ended June 30, 2019 2.8 Total $ 43.6 As of December 31, 2018, future minimum noncancelable payments for operating leases are as follows: (In millions) Year ending December 31, Amount 2019 $ 12.1 2020 8.3 2021 4.6 2022 2.6 2023 1.9 Thereafter 28.1 Total $ 57.6
Lessee Arrangements	Lessee Arrangements The Company determines at contract inception whether the contract represents or contains a lease and conveys the right to control the use of an identified asset over a period of time in exchange for consideration. For leases with terms greater than 12 months, the Company recognizes right-of-use assets and lease obligations at the lease commencement date based on a present value of lease payments over the lease term. Lease payments included in the measurement of right-of-use assets and lease obligations consist of: (i) fixed payments, including periodic rent increases and excluding any lease incentives paid or payable to the Company by a lessor, and (ii) certain variable payments that depend on an index or a market rate measured on the commencement date. The Company estimates its incremental borrowing rate based on the remaining lease term and remaining lease payments, as well as other information available at lease commencement since a readily determinable implicit rate is not provided in the Company's leases. The Company has elected to utilize a portfolio approach as it pertains to the application of the appropriate discount rates to its portfolios of leases. The weighted average discount rate for operating leases was 5.21% as of June 30, 2019 . Right-of-use assets for operating leases are initially measured on the lease commencement date and include any initial direct costs incurred, as well as lease obligation amounts, net of any lease incentives received from a lessor. Lease expense for operating leases is recognized on a straight-line basis over the lease term which includes: (i) a non-cancelable term during which the Company has a right to use an underlying asset, (ii) renewal options that extend the lease, are in the control of the lessor and are reasonably certain to be exercised, and (iii) options to terminate the lease before the end of its non-cancelable term that are not reasonably certain to be exercised. Variable payments that are excluded from the measurement of right-of-use assets and lease obligations consist primarily of non-lease related services, the Company's proportionate share of operating expenses for the leased facilities and certain payments related to excess mileage and usage charges for the leased vehicles and equipment. Such variable payments are recognized as lease expense in the results of operations when the obligation is incurred. The Company does not record right-of-use assets and lease obligations for leases with an initial term of 12 months or less and recognizes lease expense on a straight-line basis over the lease term. Finance leases are included in "Property and equipment, net", "Debt payable within one year" and "Debt payable after one year" in the accompanying unaudited Consolidated Balance Sheets and are not material at June 30, 2019 and December 31, 2018. The Company leases manufacturing and office facilities, as well as certain vehicles and equipment under operating leases. Certain manufacturing facilities are leased under land and building lease arrangements where lease terms as of June 30, 2019 consist of a remaining non-cancelable lease term of up to 8.2 years and renewal options that are reasonably certain to be exercised for an additional term of up to 32.0 years . The weighted average remaining lease term for operating leases was 15.0 years as of June 30, 2019 . The following table summarizes components of lease expense for the three and six months ended June 30, 2019 : (In millions) Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense $ 3.1 $ 6.4 Variable lease expense 1.3 2.5 Short-term lease expense 0.5 0.9 Total lease expense $ 4.9 $ 9.8 The following table summarizes lease liability maturities as of June 30, 2019 : (In millions) Year ending December 31, Amount 2019 $ 5.9 2020 8.9 2021 5.3 2022 3.0 2023 2.1 Thereafter 26.7 Total undiscounted lease payments 51.9 Less: imputed interest (15.3 ) Present value of lease payments 36.6 Less: operating lease obligations payable within one year (9.3 ) Long-term operating lease obligations $ 27.3 The following table summarizes supplemental cash flow information related to leases during the six months ended June 30, 2019 : (In millions) Amount Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 6.4 Operating lease right of use assets obtained in exchange for new lease obligations: Upon adoption of Topic 842 $ 40.8 During the six months ended June 30, 2019 2.8 Total $ 43.6 As of December 31, 2018, future minimum noncancelable payments for operating leases are as follows: (In millions) Year ending December 31, Amount 2019 $ 12.1 2020 8.3 2021 4.6 2022 2.6 2023 1.9 Thereafter 28.1 Total $ 57.6

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense/benefit attributable to continuing operations during the three months ended June 30, 2019 and 2018 was an income tax expense of $5.7 million and an income tax benefit of $5.3 million , respectively, representing effective tax rates of 64.8% and 15.4% . The difference in income tax at the U.S. federal income tax rate of 21.0% and GCP’s overall income tax rate for the three months ended June 30, 2019 were primarily attributable to non-deductible expenses and the effect of tax rates in foreign jurisdictions. The difference between the provision for income taxes at the U.S. federal income tax rate of 21.0% and GCP’s overall income tax rate for the three months ended June 30, 2018 were primarily attributable to the effect of tax rates in foreign jurisdictions and non-deductible expenses. Income tax benefit/expense attributable to continuing operations during the six months ended June 30, 2019 and 2018 was an income tax benefit of $ 10.7 million and an income tax expense of $8.2 million , respectively, representing effective tax rates of 148.6% and 23.7% . The difference between the provision for income taxes at the U.S. federal income tax rate of 21.0% and GCP’s overall income tax rate for the six months ended June 30, 2019 was primarily attributable to the finalization of the Transition Tax regulations issued in January 2019, resulting in a tax benefit from the release of an uncertain tax position in the amount of $20.2 million , partially offset by a tax expense of $3.6 million on changes to GCP’s 2017 income tax liability and Transition Tax, valuation allowance adjustments, as well as non-deductible expenses and the effect of tax rates in foreign jurisdictions. The difference in income tax at the U.S. federal income tax rate of 21.0% and GCP's overall income tax rate for the six months ended June 30, 2018 was primarily attributable to first quarter changes in estimates related to the 2017 Tax Act in the amount of $12.5 million , as well as the effect of valuation allowances, non-deductible expenses and the effect of tax rates in foreign jurisdictions. During the three months ended June 30, 2019 and 2018, GCP recorded an income tax benefit of $0.1 million and an income tax expense of $0.7 million , respectively, attributable to discontinued operations. During the six months ended June 30, 2019 and 2018, GCP recorded income tax expense attributable to discontinued operations of $2.2 million and $7.9 million , respectively. Please refer to Note 19, "Discontinued Operations," to the accompanying unaudited Consolidated Financial Statements for further details regarding the Darex transaction. Tax Reform During the year ended December 31, 2018, GCP recorded a liability of $20.2 million for an unrecognized tax benefit related to certain capital gains recognized as a result of the application of the Transition Tax. As a result of clarifications issued in January 2019 by the Internal Revenue Service (IRS) in the final treasury regulations under Code Section 965, GCP decreased its liability for unrecognized tax benefits by $20.2 million during the six months ended June 30, 2019 . In addition, the application of the final regulations resulted in an increase to GCP’s long-term tax payable by $3.4 million and an increase of GCP's short-term tax payable by $0.2 million . GCP has elected to pay the Transition Tax over the eight-year period as provided in the 2017 Tax Act. As of June 30, 2019 , the unpaid balance of the Transition Tax obligation is $41.1 million , net of overpayments and foreign tax credits. After considering overpayments, the outstanding payable is due between April 2022 and April 2025. For additional information related to the 2017 Tax Act, please refer to Note 7, "Income Taxes," to the Company's Consolidated Financial Statements included in the 2018 Annual Report on Form 10-K. Repatriation In general, it is GCP's practice and intention to permanently reinvest the earnings of its foreign subsidiaries and repatriate earnings only when the tax impact is efficient. This position has not changed subsequent to the one-time transition tax under the Tax Act. Valuation Allowance In evaluating GCP's ability to realize its deferred tax assets, GCP considers all reasonably available positive and negative evidence, including recent earnings experience, expectations of future taxable income and the tax character of that income, the period of time over which temporary differences become deductible and the carryforward and/or carryback periods available to GCP for tax reporting purposes in the related jurisdiction. In estimating future taxable income, GCP relies upon assumptions and estimates about future activities, including the amount of future federal, state and foreign pretax operating income that GCP will generate; the reversal of temporary differences; and the implementation of feasible and prudent tax planning strategies. GCP records a valuation allowance to reduce deferred tax assets to the amount that it believes is more likely than not to be realized. Income tax expense for valuation allowances was immaterial during the three months ended June 30, 2019 and 2018. During the six months ended June 30, 2019 and 2018, GCP incurred income tax expense for valuation allowances of $0.5 million and $1.0 million , respectively. These valuation allowance adjustments result from losses generated in certain countries, primarily France and India. In connection with the Separation, GCP and Grace entered into various agreements that govern the relationship between the parties going forward, including a tax matters agreement (the "Tax Sharing Agreement"). Under the Tax Sharing Agreement, GCP and Grace will indemnify and hold each other harmless in accordance with the principles outlined therein.

Pension Plans and Other Postret

Pension Plans and Other Postretirement Benefit Plans	6 Months Ended
	Jun. 30, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension Plans and Other Postretirement Benefit Plans	Pension Plans and Other Postretirement Benefit Plans Pension Plans GCP sponsors defined benefit pension plans, primarily in the U.S. and the U.K., in which GCP employees and former employees participate. GCP records an asset or a liability to recognize the funded status of these pension plans in its accompanying unaudited Consolidated Balance Sheets. The following table presents the funded status of GCP's overfunded, underfunded and unfunded defined pension plans: (In millions) June 30, 2019 December 31, 2018 Overfunded defined benefit pension plans $ 22.3 $ 22.5 Underfunded defined benefit pension plans (26.7 ) (24.2 ) Unfunded defined benefit pension plans (23.8 ) (23.9 ) Total underfunded and unfunded defined benefit pension plans (50.5 ) (48.1 ) Pension liabilities included in other current liabilities (1.3 ) (1.3 ) Net funded status $ (29.5 ) $ (26.9 ) Components of Net Periodic Benefit Cost The components of GCP's net periodic benefit cost for the three and six months ended June 30, 2019 and 2018 are as follows: Three Months Ended June 30, 2019 2018 Pension Pension (In millions) U.S. Non-U.S. U.S. Non-U.S. Service cost $ 1.7 $ 0.6 $ 2.0 $ 0.8 Interest cost 1.5 1.3 1.4 1.4 Expected return on plan assets (1.6 ) (1.5 ) (1.9 ) (1.8 ) Mark-to-market adjustment — — — (0.3 ) Gain on curtailments, settlements, and terminations — — — (0.1 ) Net periodic benefit cost (1) $ 1.6 $ 0.4 $ 1.5 $ — Six Months Ended June 30, 2019 2018 Pension Pension (In millions) U.S. Non-U.S. U.S. Non-U.S. Service cost $ 3.2 $ 1.3 $ 4.0 $ 1.6 Interest cost 2.9 2.7 2.8 2.8 Expected return on plan assets (3.2 ) (3.0 ) (3.8 ) (3.6 ) Mark-to-market adjustment — — — (0.3 ) Gain on curtailments, settlements, and terminations — — — (0.1 ) Net periodic benefit cost (income) (1)(2) $ 2.9 $ 1.0 $ 3.0 $ 0.4 ________________________________ (1) Service cost component of net periodic benefit cost is included in "Selling, general and administrative expenses" and "Cost of goods sold" in the accompanying unaudited Consolidated Statements of Operations. All other components of net periodic benefit cost are presented in "Other income, net," within the accompanying unaudited Consolidated Statements of Operations. (2) During the three and six months ended June 30, 2019, the Company recognized a curtailment gain of $0.0 million and $0.2 million , respectively, within the gain on sale of Indonesia related to its delayed closing as a part of Darex divestiture. Please refer to Note 19, "Discontinued Operations" for further information. Other Postretirement Benefit (OPEB) Plans GCP provides postretirement health care benefits for certain qualifying retired employees. As of June 30, 2019 and December 31, 2018, the related long-term liability was $1.8 million and $1.7 million . As of June 30, 2019 and December 31, 2018, accumulated other comprehensive income was $0.5 million and $0.4 million , respectively, net of related tax impact of $0.1 million as of the end of each period. The related expense for the three and six months ended June 30, 2019 was $0.1 million . Plan Contributions and Funding GCP intends to satisfy its funding obligations under the U.S. qualified pension plans and to comply with all of the requirements of the Employee Retirement Income Security Act of 1974, as amended ("ERISA"). For ERISA purposes, funded status is calculated on a different basis than under GAAP. GCP intends to fund non-U.S. pension plans based on applicable legal requirements, as well as actuarial and trustee recommendations. During the three and six months ended June 30, 2019 , GCP contributed $0.6 million and $1.5 million , respectively, to these non-U.S. plans. During the three and six months ended June 30, 2018, GCP contributed $0.5 million and $3.9 million , respectively, to these non-U.S. plans. Defined Contribution Retirement Plan GCP sponsors a defined contribution retirement plan for its employees in the U.S. which is a qualified plan under section 401(k) of the U.S. tax code. Under this plan, GCP contributes an amount equal to 100% of employee contributions, up to 6% of an individual employee's salary or wages. Effective January 1, 2018, GCP amended the defined contribution plan whereby GCP contributes up to an additional 2% of 100% of applicable employee compensation subject to a three year vesting requirement. Applicable employees include those beginning employment with GCP on or after January 1, 2018 who are not eligible to participate the GCP Applied Technologies Inc. Retirement Plan for Salaried Employees, which closed to new hires effective January 1, 2018. GCP's costs related to these benefit plans amounted to $1.2 million and $2.5 million , respectively, during the three and six months ended June 30, 2019 and $1.5 million and $2.5 million , respectively, during the three and six months ended June 30, 2018. These costs are included in "Selling, general and administrative expenses" and "Cost of goods sold" in the accompanying unaudited Consolidated Statements of Operations.

Other Balance Sheet Accounts

Other Balance Sheet Accounts	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other Balance Sheet Accounts	Other Balance Sheet Accounts The following is a summary of other current assets at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Other Current Assets: Non-trade receivables $ 19.8 $ 25.0 Prepaid expenses and other current assets 12.4 9.2 Income taxes receivable 11.8 10.4 Total other current assets $ 44.0 $ 44.6 The following is a summary of other current liabilities at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Other Current Liabilities: Accrued customer volume rebates $ 23.6 $ 35.3 Accrued compensation (1) 13.4 16.4 Income taxes payable 12.1 17.2 Accrued interest 4.1 4.0 Pension liabilities 1.3 1.3 Restructuring liability 3.8 10.2 Other accrued liabilities (2) 46.9 61.1 Total other current liabilities $ 105.2 $ 145.5 ________________________________ (1) Accrued compensation presented in the table above includes salaries and wages, as well as estimated current amounts due under the annual and long-term employee incentive programs. (2) Other accrued liabilities presented in the table above as of June 30, 2019 and December 31, 2018 include $0.5 million and $13.6 million , respectively, representing the current portion of the liability related to the delayed closings associated with the Company's divestiture of Darex, as discussed in Note 19, "Discontinued Operations."

Commitments and Contingent Liab

Commitments and Contingent Liabilities	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments and Contingent Liabilities GCP enters into certain purchase commitments and is a party to many contracts containing guarantees and indemnification obligations, as described in Note 10, "Commitments and Contingent Liabilities" to the Company's Consolidated Financial Statements included in the 2018 Annual Report in the Form 10-K. There have been no material changes to these commitments and obligations during the six months ended June 30, 2019 . Environmental Matters GCP is subject to loss contingencies resulting from extensive and evolving federal, state, local and foreign environmental laws and regulations relating to the generation, storage, handling, discharge, disposition and stewardship of hazardous wastes and other materials. GCP recognizes accrued liabilities for anticipated costs associated with response efforts if, based on the results of the assessment, it concluded that a probable liability has been incurred and the cost can be reasonably estimated. As of June 30, 2019 and December 31, 2018 , GCP did no t have any material environmental liabilities. GCP's environmental liabilities are reassessed whenever circumstances become better defined or response efforts and their costs can be better estimated. These liabilities are evaluated based on currently available information, including the progress of remedial investigations at each site, the current status of discussions with regulatory authorities regarding the method and extent of remediation at each site, existing technology, prior experience in contaminated site remediation and the apportionment of costs among potentially responsible parties. Financial Assurances Financial assurances have been established for a variety of purposes, including insurance, environmental matters and other matters. At June 30, 2019 and December 31, 2018 , GCP had gross financial assurances issued and outstanding of approximately $5 million which were composed of standby letters of credit. The letters of credit are related primarily to customer advances and other performance obligations as of June 30, 2019 and December 31, 2018. These arrangements guarantee the refund of advance payments received from customers in the event that the product is not delivered or warranty obligations are not fulfilled in accordance with the contract terms. These obligations could be called by the beneficiaries at any time before the expiration date of the particular letter of credit if the Company fails to meet certain contractual requirements. Lawsuits and Investigations From time to time, GCP and its subsidiaries are parties to, or targets of, lawsuits, claims, investigations and proceedings which are managed and defended in the ordinary course of business. While GCP is unable to predict the outcome of these matters, it does not believe, based upon currently available facts, that the ultimate resolution of any of such pending matters will have a material adverse effect on its overall financial condition, results of operations or cash flows for the three and six months ended June 30, 2019. Accounting for Contingencies Although the outcome of each of the matters discussed above cannot be predicted with certainty, GCP has assessed the risk and has made accounting estimates and disclosures as required under GAAP.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Shareholders' Equity	Shareholders' Equity Stockholder Rights Plan On March 15, 2019, the Board of Directors (the "Board") declared a dividend of one preferred share purchase right (a “Right”) for each outstanding share of GCP common stock with par value $0.01 per share and adopted a stockholder rights plan (the “Rights Agreement”). The dividend was distributed in a non-cash transaction on March 25, 2019 to the stockholders of record on that date. Each Right will allow its holder to purchase from the Company one one-hundredth of a share of Series A Junior Participating Preferred Stock, par value $0.01 per share (a “Preferred Share”) for $150 (the “Exercise Price”), once the Rights become exercisable. This portion of a Preferred Share will give the stockholder approximately the same dividend, voting and liquidation rights as would one share of GCP common stock. Prior to exercise, the Right does not give its holder any dividend, voting, or liquidation rights. The fair value of the dividend was not material on March 15, 2019. The Rights will not be exercisable until 10 days after the public announcement that a person or group has become an “Acquiring Person” (as defined in the Rights Agreement) by obtaining beneficial ownership of 15% or more of the Company’s outstanding shares of common stock (provided, that if a stockholder’s beneficial ownership as of the Company’s announcement of the adoption of the Rights Agreement was at or above 15% , that stockholder’s existing ownership percentage would be grandfathered, but the Rights would become exercisable if at any time after such announcement, the stockholder increases its ownership percentage by 0.001% or more) (the “Distribution Date”). If a person or group becomes an Acquiring Person, all holders of Rights except the Acquiring Person may, for the Exercise Price, purchase shares of the Company’s common stock with a market value of $300 , based on the market price of the common stock prior to such acquisition. In addition, after a person or group becomes an Acquiring Person, but before an Acquiring Person owns 50% or more of the Company’s outstanding shares of common stock, the Board may extinguish the Rights by exchanging one share of common stock or an equivalent security for each Right, other than Rights held by the Acquiring Person. In addition, if the Company is later acquired in a merger or similar transaction after the Distribution Date, all holders of Rights except the Acquiring Person may, for $150 , purchase shares of the acquiring corporation with a market value of $300 based on the market price of the acquiring corporation’s stock, prior to such merger. The Rights will expire on March 14, 2020, subject to a possible earlier expiration to the extent provided in the Rights Agreement. Preferred Stock On March 15, 2019, GCP authorized 10,000,000 shares of its Preferred Stock with a par value of $0.01 per share as Series A Junior Participating Preferred Stock. Stockholders' Equity Activity The following table summarizes the Company’s stockholders' equity activity during the three months ended June 30, 2019 and 2018. Common Stock Treasury Stock (In millions) Number of Shares Par Value Number of Shares Cost Additional Paid-in Capital Accumulated Earnings Accumulated Other Comprehensive Loss Noncontrolling Interests Total Stockholders' Equity Balance, March 31, 2018 72.2 $ 0.7 0.2 $ (4.1 ) $ 35.3 $ 542.1 $ (71.4 ) $ 1.9 $ 504.5 Net (loss) income — — — — — (27.9 ) — 0.1 (27.8 ) Issuance of common stock in connection with stock plans 0.1 — — — — — — — — Share-based compensation — — — — 3.9 — — — 3.9 Exercise of stock options 0.1 — — — 1.6 — — — 1.6 Share repurchases (1) — — — (0.6 ) — — — — (0.6 ) Other comprehensive loss — — — — — — (33.0 ) — (33.0 ) Balance, June 30, 2018 72.4 $ 0.7 0.2 $ (4.7 ) $ 40.8 $ 514.2 $ (104.4 ) $ 2.0 $ 448.6 Balance, March 31, 2019 72.9 $ 0.7 0.3 $ (8.0 ) $ 44.6 $ 585.3 $ (116.8 ) $ 2.2 $ 508.0 Net income — — — — — 2.6 — — 2.6 Issuance of common stock in connection with stock plans (2) — — — — — — — — — Share-based compensation — — — — 3.9 — — — 3.9 Exercise of stock options 0.1 — — — 1.7 — — — 1.7 Share repurchases (1) — — — — — — — — — Other comprehensive loss — — — — — — (3.9 ) — (3.9 ) Balance, June 30, 2019 73.0 $ 0.7 0.3 $ (8.0 ) $ 50.2 $ 587.9 $ (120.7 ) $ 2.2 $ 512.3 ________________________________ (1) During the three months ended June 30, 2018, GCP withheld and retained approximately 22,000 shares of Company common stock in a non-cash transaction with a cost of $0.6 million in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the three months ended June 30, 2019, GCP withheld and retained approximately 300 shares of Company common stock in a non-cash transaction with a cost which was immaterial. During the three months ended June 30, 2018, cash payments for such tax withholding obligations were $0.6 million . (2) The par value of shares issued is not included in the table due to rounding.

Restructuring and Repositioning

Restructuring and Repositioning Expenses	6 Months Ended
	Jun. 30, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Repositioning Expenses	Restructuring and Repositioning Expenses GCP's Board of Directors approves all major restructuring and repositioning programs. Restructuring may involve the discontinuation of significant product lines or the shutdown of significant facilities. From time to time, GCP takes additional restructuring actions, including involuntary employee terminations that are not a part of a major program. Repositioning activities generally represent major strategic or transformational actions to enhance the value and performance of the Company, improve business efficiency or optimize the Company’s footprint. Repositioning expenses associated with the 2019, 2018 and 2017 Plans, as well as a review of strategic, financial and operational alternatives, are primarily related to consulting, other professional services and recruitment costs associated with the Company’s organizational realignment and advancing its technology strategy. Due to the scope and complexity of the Company’s repositioning activities, the range of estimated repositioning expenses and capital expenditures could increase or decrease and the timing of incurrence could change. 2019 Restructuring and Repositioning Plan (the “2019 Plan”) On February 22, 2019, the Board of Directors approved a business restructuring and repositioning plan (the “2019 Plan”). The 2019 Plan is focused on GCP’s global supply chain strategy, processes and execution, including our manufacturing, purchasing, logistics, and warehousing operations. The plan also addresses GCP’s service delivery model, primarily in North America, to streamline the Company’s pursuit of combined admixture and VERIFI ® opportunities. The Company expects to incur total pre-tax costs in connection with the 2019 Plan of approximately $15 million to $20 million , of which costs ranging from approximately $4 million to $7 million are related to restructuring activities and costs of approximately $11 million to $13 million are related to repositioning activities. In addition, the Company expects to incur approximately $2 million to $3 million of capital expenditures associated with the program. Total expected restructuring activity costs consist of approximately $2 million to $3 million of severance and other employee-related costs and $1 million to $3 million of other associated costs. In addition, GCP expects to incur approximately $1 million of asset impairments. As of June 30, 2019, there were no restructuring activity costs recognized under the 2019 Plan since inception. Repositioning costs consist primarily of consulting services to assist GCP in advancing its technology strategy. During the three and six months ended June 30, 2019, GCP incurred repositioning expenses of $1.4 million and $3.3 million , respectively, related to the 2019 Plan. Cash payments made for repositioning under the 2019 Plan for the three and six months ended June 30, 2019 were $2.1 million and $2.3 million , respectively. Substantially all of the restructuring and repositioning activities are expected to be settled in cash and completed by December 31, 2020. 2018 Restructuring and Repositioning Plan (the “2018 Plan”) On August 1, 2018, the Board of Directors of the Company approved a business restructuring and repositioning plan. The 2018 Plan is designed to streamline operations and improve profitability, primarily within the concrete admixtures product line of the SCC segment, by focusing on the Company's core markets, rationalizing non-profitable geographies within the SCC and SBM segments, reducing its global cost structure and accelerating the integration of VERIFI ® into the Company’s global admixtures business. The Company expects to incur total costs in connection with the 2018 Plan of approximately $32 million to $35 million , of which $21 million to $24 million relate to restructuring activities and asset impairments, and $11 million relate to repositioning activities. Total expected restructuring activity costs consist of approximately $12 million to $13 million of severance and other employee-related costs, $7 million to $8 million of asset impairments, $1 million of facility exit costs and $ 1 million to $2 million of other associated costs. Total expected restructuring activity costs are attributable as follows: (i) $16.0 million to $ 18.0 million to the SCC segment and (ii) $5.0 million to $6.0 million to the SBM segment. Substantially all of the restructuring actions are expected to be completed by May 31, 2020 and result in the net reduction of approximately 8% - 10% of the Company's workforce. Repositioning activities consist primarily of consulting services to assist GCP in advancing its technology strategy and are expected to be completed by December 31, 2019. As of June 30, 2019 , the cumulative restructuring activity costs recognized under the 2018 Plan since inception were $20.9 million , of which $15.4 million was attributable to the SCC segment and $5.5 million was attributable to the SBM segment. Cumulative restructuring activity costs incurred to date consisted of $11.8 million of severance and employee-related costs, $7.8 million of asset impairments charges, $0.6 million of facility exit costs and $0.7 million of other associated costs. As of June 30, 2019 , repositioning expenses of $1.8 million and $5.1 million , respectively, were incurred during the three and six months ended June 30, 2019 and $10.4 million were incurred since inception. As of June 30, 2019 , cash payments for repositioning for the six months ended June 30, 2019 and since inception were $7.7 million and $7.9 million , respectively. With the exception of asset impairments, the Company expects to settle all of the restructuring and repositioning costs related to the 2018 Plan in cash. 2017 Restructuring and Repositioning Plan (the “2017 Plan”) On June 28, 2017, the Board of Directors approved a restructuring and repositioning plan that includes actions to streamline GCP's operations, reduce its global cost structure and reposition itself as a construction products technologies company. GCP expects to incur total costs in connection with the 2017 Plan of approximately $29 million , of which $19 million is related to restructuring activities and asset impairments, and $10 million is related to repositioning activities. As of June 30, 2019, the restructuring activities were substantially completed. As of June 30, 2019 , the cumulative restructuring activity costs recognized under the 2017 Plan since its inception were $19.0 million which were attributable as follows: (i) $4.6 million to the SCC segment, (ii) $3.3 million to the SBM segment, (iii) $2.8 million to the Corporate function and (iv) $8.3 million to discontinued operations. Cumulative restructuring activity costs incurred to date consisted of $17.3 million of severance and employee-related costs, $1.5 million of asset impairments, and $0.2 million of facility exit costs. Additionally, GCP expects to incur approximately $10 million to $15 million of capital expenditures related to repositioning activities, which includes the build-out of two manufacturing plants in Asia Pacific that will replace shared facilities sold as a part of the Darex divestiture. GCP expects all of its repositioning activities to be classified within continuing operations and substantially completed by March 31, 2020. As of June 30, 2019 , the cumulative repositioning activity costs and capital expenditures recognized for the 2017 Plan since its inception were approximately $9.1 million and $9.3 million , respectively. During the three and six months ended June 30, 2019 , GCP incurred repositioning expenses of $0.2 million and $0.3 million , respectively. During the three and six months ended June 30, 2018, GCP incurred repositioning expenses of $1.1 million and $2.0 million , respectively. During the six months ended June 30, 2019 , total cash payments related to such repositioning expenses were $2.6 million , which included $1.1 million for capital expenditures. As of June 30, 2019 , cumulative cash payments made for repositioning under the 2017 Plan from its inception amounted to $16.7 million , including capital expenditures. The Company expects to settle in cash substantially all of the costs related to the 2017 Plan. Restructuring Expenses and Asset Impairments The following restructuring expenses and asset impairment charges were incurred under the 2018 and 2017 Plans and other plans during each period: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Severance and other employee costs $ 0.2 $ (0.9 ) 0.5 $ (0.7 ) Asset impairments 3.8 — 4.0 0.4 Other associated costs 0.5 — 0.7 — Total restructuring expenses and asset impairments $ 4.5 $ (0.9 ) $ 5.2 $ (0.3 ) Less: restructuring expenses and asset impairments reflected in discontinued operations 0.1 (0.3 ) 0.2 0.8 Total restructuring expenses and asset impairments from continuing operations $ 4.4 $ (0.6 ) $ 5.0 $ (1.1 ) GCP incurred restructuring expenses and asset impairment charges related to its two operating segments and Corporate function as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 SCC $ 1.3 $ (0.6 ) $ 1.9 $ (1.0 ) SBM 3.2 0.1 3.2 (0.4 ) Corporate (0.1 ) (0.1 ) (0.1 ) 0.3 Total restructuring expenses and asset impairments from continuing operations $ 4.4 $ (0.6 ) $ 5.0 $ (1.1 ) Restructuring expenses and asset impairments reflected in discontinued operations 0.1 (0.3 ) 0.2 0.8 Total restructuring expenses and asset impairments $ 4.5 $ (0.9 ) $ 5.2 $ (0.3 ) Restructuring liabilities were $ 3.8 million and $10.2 million , respectively, as of June 30, 2019 and December 31, 2018 . These liabilities are included within “Other current liabilities” in the accompanying unaudited Consolidated Balance Sheets. GCP settled in cash substantially all of the remaining liabilities related to the 2017 Plan during the six months ended June 30, 2019. GCP expects to settle in cash substantially all of the remaining liabilities related to the 2018 Plan by December 31, 2019. The following table summarizes the Company’s restructuring liability activity: 2018 Plan 2017 Plan (In millions) Severance and other employee costs Facility exit costs Other Costs Severance and other employee costs Other plans Total Balance, December 31, 2018 $ 7.7 $ 0.2 $ — $ 1.8 $ 0.5 $ 10.2 Expense (1) 0.4 — 0.1 — (0.1 ) 0.4 Payments (2.2 ) (0.1 ) — (1.5 ) (0.2 ) (4.0 ) Impact of foreign currency and other (0.1 ) — — — (0.1 ) (0.2 ) Balance, March 31, 2019 $ 5.8 $ 0.1 $ 0.1 $ 0.3 $ 0.1 $ 6.4 Expense (1) — — 0.2 (0.1 ) 0.3 0.4 Payments (2.3 ) (0.1 ) (0.2 ) (0.1 ) (0.4 ) (3.1 ) Impact of foreign currency and other — — — 0.1 — 0.1 Balance, June 30, 2019 $ 3.5 $ — $ 0.1 $ 0.2 $ — $ 3.8 ________________________________ (1) Asset impairment charges of $ 3.8 million and $4.0 million , respectively, for the three and six months ended June 30, 2019 related to the 2018 and 2017 Plans are primarily recorded as a reduction to "Properties and equipment, net" in the accompanying unaudited Consolidated Balance Sheets. During the three and six months ended June 30, 2019, asset impairment charges of $0.7 million and $0.9 million , respectively, were attributable to the SCC segment and $3.1 million and $3.1 million , respectively, were attributable to the SBM segment. Other associated costs attributable to SCC, of $0.3 million and $0.4 million , respectively, for the three and six months ended June 30, 2019 related to the 2018 Plan are recorded as a reduction to "Inventories, net" in the accompanying unaudited Consolidated Balance Sheets. These expenses are not recorded to the restructuring liability and therefore, are not included in the table above. Strategic Alternatives Plan On February 27, 2019, the Company announced a comprehensive review of strategic alternatives to enhance shareholder value. Over the course of this review, GCP contacted and engaged with both strategic industry players and private equity investors. This process did not result in a transaction that would provide adequate value to the Company's shareholders, and as a result, GCP has determined that it will be pursuing its standalone strategic and financial plan. During the three months ended June 30, 2019, GCP incurred $2.5 million of repositioning expenses related to our Strategic Alternatives Plan, primarily consisting of professional service fees.

Other Comprehensive Loss

Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Other Comprehensive Loss	Other Comprehensive Loss The following tables present the pre-tax, tax, and after-tax components of GCP's other comprehensive loss for the three and six months ended June 30, 2019 and 2018 : Three Months Ended June 30, 2019 (In millions) Pre-Tax Amount Tax Expense After-Tax Amount Currency translation adjustments (1) $ (3.9 ) $ — $ (3.9 ) Other comprehensive loss attributable to GCP shareholders $ (3.9 ) $ — $ (3.9 ) Six Months Ended June 30, 2019 (In millions) Pre-Tax Amount Tax Benefit After-Tax Amount Currency translation adjustments (1) $ (0.6 ) $ — $ (0.6 ) Loss from hedging activities (0.1 ) — (0.1 ) Other comprehensive loss attributable to GCP shareholders $ (0.7 ) $ — $ (0.7 ) Three Months Ended June 30, 2018 (In millions) Pre-Tax Amount Tax Expense After-Tax Amount Defined benefit pension and other postretirement plans $ (0.8 ) $ 0.2 $ (0.6 ) Currency translation adjustments (1) (32.5 ) — (32.5 ) Gain from hedging activities 0.1 — 0.1 Other comprehensive loss attributable to GCP shareholders $ (33.2 ) $ 0.2 $ (33.0 ) Six Months Ended June 30, 2018 (In millions) Pre-Tax Amount Tax Benefit After-Tax Amount Defined benefit pension and other postretirement plans $ (0.8 ) $ 0.2 $ (0.6 ) Currency translation adjustments (1) (18.2 ) — (18.2 ) Gain from hedging activities 0.1 — 0.1 Other comprehensive loss attributable to GCP shareholders $ (18.9 ) $ 0.2 $ (18.7 ) __________________________ (1) Currency translation adjustments did not have a corresponding tax effect. The following tables present the changes in accumulated other comprehensive loss, net of tax, for the six months ended June 30, 2019 and 2018 : (In millions) Defined Benefit Pension and Other Postretirement Plans Currency Translation Adjustments Hedging Activities Total Balance, December 31, 2018 $ (2.2 ) $ (117.8 ) $ — $ (120.0 ) Current-period other comprehensive loss — (0.6 ) (0.1 ) (0.7 ) Balance, June 30, 2019 $ (2.2 ) $ (118.4 ) $ (0.1 ) $ (120.7 ) (In millions) Defined Benefit Pension and Other Postretirement Plans Currency Translation Adjustments Hedging Activities Total Balance, December 31, 2017 $ 0.4 $ (86.0 ) $ (0.1 ) $ (85.7 ) Current-period other comprehensive (loss) income (0.6 ) (18.2 ) 0.1 (18.7 ) Balance, June 30, 2018 $ (0.2 ) $ (104.2 ) $ — $ (104.4 ) Please refer to Note 8, "Pension Plans and Other Postretirement Benefit Plans," for a discussion of pension plans and other postretirement benefit plans.

Stock Incentive Plans

Stock Incentive Plans	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Incentive Plans	Stock Incentive Plans Stock-Based Compensation Accounting GCP grants stock options, restricted stock units (the "RSUs") and performance-based units (the "PBUs") with or without market conditions which vest upon the satisfaction of a performance condition and/or a service condition. Please refer to Note 14, "Stock Incentive Plans" to the Company's Consolidated Financial Statements included in the 2018 Annual Report in the Form 10-K for further information on these awards. In accordance with U.S. GAAP, GCP estimates the fair value of equity awards issued at the grant date. The fair value of the awards is recognized as stock-based compensation expense on a straight line basis, net of estimated forfeitures, over the employee’s requisite service period for each separately vesting portion of the award. Total stock-based compensation expense is included in "Income (loss) from continuing operations before income taxes" in the accompanying unaudited Consolidated Statements of Operations and was $3.1 million and $5.0 million , respectively during the three and six months ended June 30, 2019 , and $3.0 million and $4.9 million , respectively, during the three and six months ended June 30, 2018. The Company issues new shares of common stock upon exercise of stock options. In accordance with certain provisions of the GCP Equity and Incentive Plan (the "Plan"), GCP withholds and retains shares issued to certain holders of GCP awards in order to fulfill statutory tax withholding requirements for the employees. During the six months ended June 30, 2019 and 2018, GCP withheld and retained approximately 125,700 shares and 45,000 shares, respectively, in a non-cash transaction with a cost of $3.2 million and $1.3 million , respectively, which were reflected as "Share Repurchases" in the accompanying unaudited Consolidated Statements of Equity. During the six months ended June 30, 2019 and 2018, cash payments for such tax withholding obligations were $3.2 million and $1.3 million , respectively. As of June 30, 2019 , approximately 7.6 million shares of common stock were reserved and available for future grant under the Plan. Stock Options The following assumptions were utilized in the Black-Scholes option pricing model for estimating the fair value of GCP's stock options granted during the six months ended June 30, 2019 and 2018 : Six Months Ended June 30, Assumptions used to calculate expense for stock options: 2019 2018 Risk-free interest rate 2.35 -2.64% 2.68 - 2.90% Average life of options (years) 5.5 - 6.5 5.5 - 6.5 Volatility 28.02 - 28.59% 27.91 - 30.65% Dividend yield — — Weighted average fair value per stock option $8.74 $11.02 The following table sets forth information relating to stock options denominated in GCP stock during the six months ended June 30, 2019 : Stock Option Activity Number Of Weighted Weighted Aggregated Outstanding, December 31, 2018 1,518 21.18 3.75 $ 7,145 Options exercised (267 ) 18.66 Options forfeited/expired/canceled (27 ) 27.66 Options granted 262 26.65 Outstanding, June 30, 2019 1,486 22.47 4.21 $ 3,806 Exercisable, June 30, 2019 1,009 19.90 3.13 $ 3,806 Vested and expected to vest, June 30, 2019 1,468 22.42 4.18 $ 3,806 The weighted average grant date fair value of options granted during the three months ended June 30, 2019 and 2018 was $9.58 and $9.70 , respectively. The aggregate intrinsic values in the table above represent the total pre-tax intrinsic value, determined as the difference between GCP's closing stock price on the last trading day of June 30, 2019 and the exercise price, multiplied by the number of in-the-money options that would have been received by the option holders had all option holders exercised their in-the-money options at period end. The amount changes based on the fair market value of GCP's stock. Total intrinsic value of all options exercised during the three and six months ended June 30, 2019 were $0.8 million and $2.5 million , respectively, and during the three and six months ended June 30, 2018 were $1.2 million and $4.7 million , respectively. At June 30, 2019 , total unrecognized stock-based compensation expense for stock options outstanding was $1.9 million and is expected to be recognized over the weighted-average period of approximately 1.1 years . Restricted Stock Units and Performance Based Units RSUs and PBUs are granted with the exercise price equal to zero and are converted to shares immediately upon vesting. As of June 30, 2019 , $7.6 million of total unrecognized compensation expense related to the RSU and PBU awards is expected to be recognized over the remaining weighted-average service period of approximately 1.6 years . RSUs The Company grants RSUs which are time-based, non-performance units. RSUs generally vest over a three year period, with some awards vesting in substantially equal amounts each year over three years and some awards vesting 100% after the third year from the date of grant. A smaller number of RSUs were designated as sign-on awards which are used for the purposes of attracting key employees and covering outstanding awards from prior employers. Such awards generally vest 100% after two years from the date of grant . RSUs are recorded at fair value on the date of grant. The common stock-settled awards are considered equity awards, with the stock compensation expense being determined based on GCP’s stock price on the grant date. The following table sets forth the RSU activity for the six months ended June 30, 2019 : RSU Activity Number Of Weighted Outstanding, December 31, 2018 363 $ 22.76 RSUs settled (237 ) 19.90 RSUs forfeited (8 ) 28.87 RSUs granted 133 26.91 RSUs outstanding, June 30, 2019 251 $ 27.45 Expected to vest as of June 30, 2019 242 $ 27.47 The weighted average grant date fair value of RSUs granted during the three months ended June 30, 2019 and 2018 was $29.52 and $28.65 per share, respectively. The weighted average grant date fair value of RSUs granted during the six months ended June 30, 2019 and 2018 was $26.91 and $32.07 per share, respectively. During the six months ended June 30, 2019 , GCP distributed 237,000 shares to settle RSUs upon vesting. During the six months ended June 30, 2018, GCP distributed approximately 116,000 shares and $1.2 million of cash to settle RSUs upon vesting. The fair value of RSUs vested during the six months ended June 30, 2019 and 2018 was $6.1 million and $4.8 million , respectively. PBUs PBUs are performance-based units which are granted by the Company either with or without market conditions and recorded at fair value on the grant date. The performance criteria for PBUs granted in 2016 was based on a 3 -year cumulative adjusted earnings per share measure. The number of shares earned by employees was based on the achievement of applicable performance targets related to such measure and could range between 0% to 200% . During the six months ended June 30, 2019, PBUs granted in 2016 were settled by the distribution of 76,461 shares of GCP common stock based on the actual performance of 68.7% achieved against the cumulative adjusted earnings per share measure during the years 2016-2018. The actual performance measure for the 2016 PBU grants was certified by the Compensation Committee during the period then ended. The performance criteria for PBUs granted in 2017 and 2018 include a 3 -year cumulative adjusted diluted earnings per share metric that is modified, up or down, based on the Company's total shareholder return ("TSR") relative to the performance of the Russell 3000 Index. For PBUs granted in 2019, such metric is modified, up or down, based on the Company's TSR relative to the performance of the Russell 3000 Specialty Chemicals and Building Materials Indices. The number of shares that ultimately vest, if any, is based on Company performance against these metrics, and can range from 0% to 200% of the target number of shares granted to employees. The 2019, 2018 and 2017 awards will become vested, if at all, three years from the grant date once actual performance is certified by the Board's Compensation Committee. Vesting is also subject to the employees' continued employment through the vesting date. The following table summarizes the assumptions used in the Monte Carlo simulations for estimating the grant date fair values of PBUs granted during the six months ended June 30, 2019 and 2018: Six Months Ended June 30, Assumptions used to calculate expense for PBUs: 2019 2018 Expected Term (Remaining Performance Period) 2.86 2.86 Expected volatility 28.46% 28.56% Risk-free interest rate 2.48% 2.38% Expected dividends — — Correlation coefficient 54.81% 38.98% Average correlation coefficient of constituents 57.09% 39.96% During the six months ended June 30, 2019 , GCP granted 167,519 PBUs to its employees with a weighted average grant date fair value of $27.40 . During the six months ended June 30, 2019 , none of these PBUs were forfeited. As of June 30, 2019, all of these PBUs were outstanding. During 2018, GCP granted 149,974 PBUs to its employees, of which 143,797 PBUs with a weighted average grant date fair value of $34.14 were outstanding as of December 31, 2018. During the six months ended June 30, 2019 , 10,249 of these PBUs were forfeited. As of June 30, 2019, 133,548 of these PBUs were outstanding with a weighted average grant date fair value of $34.03 . During 2017, GCP granted 166,821 PBUs to its employees, of which 138,915 PBUs with a weighted average grant date fair value of $28.25 were outstanding as of December 31, 2018. During the six months ended June 30, 2019 , 10,036 of these PBUs were forfeited. As of June 30, 2019, 128,879 of these PBUs were outstanding. During the six months ended June 30, 2019 , 76,461 PBUs granted in 2016 with a weighted average grant date fair value of $17.04 vested and were released to Company employees. During the six months ended June 30, 2019 , 34,840 of these awards were forfeited.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth a reconciliation of the numerators and denominators used in calculating basic and diluted earnings (loss) per share: Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share amounts) 2019 2018 2019 2018 Numerators Income (loss) from continuing operations attributable to GCP shareholders $ 3.1 $ (29.2 ) $ 17.7 $ (43.0 ) (Loss) income from discontinued operations, net of income taxes (0.5 ) 1.3 6.3 8.5 Net income (loss) attributable to GCP shareholders $ 2.6 $ (27.9 ) $ 24.0 $ (34.5 ) Denominators Weighted average common shares—basic calculation 72.6 72.1 72.5 72.0 Dilutive effect of employee stock awards (1) 0.4 — 0.4 — Weighted average common shares—diluted calculation 73.0 72.1 72.9 72.0 Basic earnings (loss) per share Income (loss) from continuing operations attributable to GCP shareholders $ 0.04 $ (0.40 ) $ 0.24 $ (0.60 ) (Loss) income from discontinued operations, net of income taxes $ (0.01 ) $ 0.02 $ 0.09 $ 0.12 Net income (loss) attributable to GCP shareholders (2) $ 0.04 $ (0.39 ) $ 0.33 $ (0.48 ) Diluted earnings (loss) per share (1) Income (loss) from continuing operations attributable to GCP shareholders $ 0.04 $ (0.40 ) $ 0.24 $ (0.60 ) (Loss) income from discontinued operations, net of income taxes $ (0.01 ) $ 0.02 $ 0.09 $ 0.12 Net income (loss) attributable to GCP shareholders (2) $ 0.04 $ (0.39 ) $ 0.33 $ (0.48 ) ________________________________ (1) Dilutive effect not applicable to periods in which GCP generated a loss from continuing operations. (2) Amounts may not sum due to rounding. GCP uses the treasury stock method to compute diluted earnings (loss) per share. During the three and six months ended June 30, 2019, 0.6 million of anti-dilutive stock awards were excluded from the computation of diluted earnings per share during each period based on the treasury stock method as a result of an income from continuing operations generated during the periods then ended. As of June 30, 2018, total outstanding options of 1.5 million and total outstanding RSUs of 0.3 million were excluded from the computation of diluted loss per share due to a loss from continuing operations incurred during the three and six months ended June 30, 2018. The following table sets forth the weighted average options and RSUs excluded from the computation of dilutive shares and diluted loss per share that would've been reflected in the "Dilutive effect of employee stock awards" line in the table above: Three Months Ended June 30, Six Months Ended June 30, (In millions of shares) 2019 2018 2019 2018 Dilutive effect: (1) Options N/A 0.5 N/A 0.5 RSUs N/A 0.2 N/A 0.2 __________________________ (1) N/A - Dilutive effect is included in computation of diluted earnings per share under the treasury stock method for periods in which GCP generated income from continuing operations.

Related Party Transactions and

Related Party Transactions and Transactions with Grace	6 Months Ended
	Jun. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions and Transactions with Grace	Related Party Transactions and Transactions with Grace Related Parties All contracts with related parties are at rates and terms that GCP believes are comparable with those that could be entered into with independent third parties. Subsequent to the Separation, transactions with Grace represent third-party transactions. Tax Sharing Agreement In connection with the Separation, the Company and Grace entered into a Tax Sharing Agreement which governs the parties’ respective rights, responsibilities and obligations with respect to tax liabilities and benefits, tax attributes, the preparation and filing of tax returns, the control of audits and other tax proceedings, as well as other matters regarding taxes. In general, and subject to the terms of the Tax Sharing Agreement, GCP is responsible for all U.S. federal, state and foreign taxes including any related interest, penalties or audit adjustments reportable on a GCP separate return (a return that does not include Grace or any of its subsidiaries). Grace is responsible for all U.S. federal, state and foreign income taxes including any related interest, penalties or audit adjustments reportable on a consolidated, combined or unitary return that includes Grace or any of its subsidiaries and GCP or any of its subsidiaries up to the Separation date. As of June 30, 2019 and December 31, 2018, GCP has recorded $4.0 million and $3.9 million , respectively, of indemnified receivables in "Other assets" and $1.9 million and $1.8 million , respectively, of indemnified payables in "Other current liabilities" in the accompanying unaudited Consolidated Balance Sheets. In addition, the Tax Sharing Agreement imposes certain restrictions on GCP and its subsidiaries, including restrictions on share issuances, business combinations, sales of assets and similar transactions that are designed to preserve the qualification of the Distribution, together with certain related transactions, under Section 355 and certain other relevant provisions of the Code. In the event that the Distribution, together with certain related transactions, does not qualify under Section 355 and certain other relevant provisions of the Code, then the Tax Sharing Agreement provides specific rules for allocating tax liabilities. In general, under the Tax Sharing Agreement, each party is expected to be responsible for any taxes imposed on and certain related amounts payable by GCP or Grace that arise from the failure of the Distribution and certain related transactions to qualify under Section 355 and certain other relevant provisions of the Code, to the extent that the failure to so qualify is attributable to actions, events or transactions relating to such party’s respective stock, assets or business, or a breach of the relevant representations or covenants made by such party in the Tax Sharing Agreement.

Operating Segment and Geographi

Operating Segment and Geographic Information	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Operating Segment and Geographic Information	Operating Segment and Geographic Information GCP is engaged in the production and sale of specialty construction chemicals and specialty building materials through two operating segments. Specialty Construction Chemicals ("SCC") operating segment manufactures and markets concrete admixtures and cement additives. Specialty Building Materials ("SBM") operating segment manufactures and markets sheet and liquid membrane systems that protect structures from water, air and vapor penetration, as well as fireproofing and other products designed to protect the building envelope. Operating Segment Data The following table presents information related to GCP's operating segments: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net Sales Specialty Construction Chemicals $ 150.4 $ 175.0 $ 282.1 $ 322.0 Specialty Building Materials 111.8 127.8 206.2 231.0 Total net sales $ 262.2 $ 302.8 $ 488.3 $ 553.0 Segment Operating Income Specialty Construction Chemicals segment operating income $ 14.2 $ 12.6 $ 22.1 $ 18.5 Specialty Building Materials segment operating income 22.3 31.8 38.2 49.9 Total segment operating income $ 36.5 $ 44.4 $ 60.3 $ 68.4 Reconciliation of Operating Segment Data to Financial Statements Corporate expenses directly related to the operating segments are allocated to the segment's operating income. GCP excludes from the segments' operating income certain functional costs, certain impacts of foreign currency exchange, as well as other corporate costs included in the table below. GCP also excludes from the segment's operating income certain ongoing defined benefit pension costs recognized during each reporting period, which include service and interest costs, the effect of expected returns on plan assets and amortization of prior service costs/credits. GCP believes that the exclusion of certain corporate costs and pension costs provides a better indicator of its operating segment performance since such costs are not managed at an operating segment level. Total segment operating income for the three and six months ended June 30, 2019 and 2018 , is reconciled below to " Income (loss) from continuing operations before income taxes " presented in the accompanying unaudited Consolidated Statements of Operations: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Total segment operating income $ 36.5 $ 44.4 $ 60.3 $ 68.4 Corporate costs (9.4 ) (8.6 ) (19.3 ) (17.5 ) Certain pension costs (2.0 ) (1.9 ) (3.9 ) (3.8 ) Other costs (1.1 ) — (3.6 ) — Repositioning expenses (5.8 ) (1.2 ) (11.2 ) (2.1 ) Restructuring expenses and asset impairments (4.4 ) 0.6 (5.0 ) 1.1 Pension MTM adjustment and other related costs, net — (0.9 ) — (0.9 ) Gain on termination and curtailment of pension and other postretirement plans — 0.1 — 0.1 Third-party and other acquisition-related costs — (0.8 ) (0.1 ) (1.6 ) Amortization of acquired inventory fair value adjustment — (0.2 ) — (0.2 ) Legacy product, environmental and other claims (0.1 ) — (0.1 ) — Net income attributable to noncontrolling interests — 0.1 0.2 0.2 Interest expense, net (1) (4.9 ) (66.0 ) (10.1 ) (78.3 ) Income (loss) from continuing operations before income taxes $ 8.8 $ (34.4 ) $ 7.2 $ (34.6 ) __________________________ (1) During the three and six months ended June 30, 2018, "Interest expense, net" includes a loss of $59.8 million as a result of a debt refinancing transaction completed on April 10, 2018. Please refer to Note 6, "Debt and Other Borrowings," in the Notes to the Consolidated Financial Statements included in Item 8 "Financial Statements and Supplementary Data" of the Annual Report on Form 10‑K. Disaggregation of Total Net Sales The Company disaggregates its revenue from contracts with customers by operating segments, which it believes best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. Geographic Area Data The table below presents information related to the geographic areas in which GCP operates. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net Sales United States $ 126.6 $ 141.1 $ 234.4 $ 258.0 Canada and Other 9.2 8.2 14.9 14.3 Total North America 135.8 149.3 249.3 272.3 Europe Middle East Africa 52.3 69.2 98.7 127.5 Asia Pacific 58.9 65.7 109.6 117.7 Latin America 15.2 18.6 30.7 35.5 Total $ 262.2 $ 302.8 $ 488.3 $ 553.0 Sales are attributed to geographic areas based on customer location. With the exception of the U.S. presented in the table above, there were no individually significant countries with sales exceeding 10% of total sales during the three and six months ended June 30, 2019 and 2018. There were no customers that individually accounted for 10% or more of the Company's accounts receivable balance as of June 30, 2019 and December 31, 2018. Disaggregation of Long-Lived Assets As a result of adopting Topic 842, the Company has recorded $36.3 million of operating lease right-of-use-assets as of June 30, 2019. The Company disaggregates such assets by operating segments and geographic areas in which GCP operates. Please refer to Note 1, "Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies" and Note 6, "Lessee Arrangements" for further discussion on the accounting treatment and impact of adopting Topic 842. The following table sets forth certain long-lived asset information related to the geographic areas in which GCP operates: (In millions) As of June 30, 2019 Operating lease right-of-use assets United States $ 12.9 Canada 0.2 Total North America 13.1 Europe, Middle East, and Africa 12.9 Asia Pacific 9.1 Latin America 1.2 Total $ 36.3 Operating lease right-of-use assets Specialty Construction Chemicals $ 18.9 Specialty Building Materials 14.0 Corporate 3.4 Total $ 36.3

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions The Company did not complete any material acquisitions during the six months ended June 30, 2019. Please refer to Note 1, "Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies" included in the 2018 Annual Report on Form 10-K for further discussion regarding the accounting treatment for business acquisitions. Acquisitions Completed in 2018 Clydebridge Holdings Limited On May 4, 2018, GCP acquired 100% of the outstanding capital stock of Clydebridge Holdings Limited which owns 100% of RIW Limited (the "RIW"), a U.K.-based supplier of waterproofing solutions for commercial and residential construction applications. The acquisition has strengthened GCP’s position in the U.K. waterproofing market and has complemented its product portfolio within the SBM operating segment by adding waterproofing capabilities for a wider range of projects. The aggregate purchase price of $29.7 million , net of cash acquired of $10.0 million , consisted of a net cash payment of $29.8 million , which was reduced by working capital adjustments of $0.1 million . During the year ended December 31, 2018, the Company finalized certain closing adjustments with the seller and recorded a $0.2 million reduction in both consideration paid and inventories. During the three months ended March 31, 2019, the Company finalized the purchase price allocation. The Company accounted for the acquisition as a business combination in accordance with provisions of ASC 805, Business Combinations ("ASC 805"). The operating results of RIW have been reflected in the results of operations for the SBM operating segment from the date of the acquisition. The fair values of assets acquired and liabilities assumed have been finalized as of June 30, 2019. At the closing of the acquisition of RIW, a portion of the consideration was placed into escrow which was ascribed to the purchase price and will be released to the sellers no later than December 30, 2020. The escrow was related to the sellers’ satisfaction of indemnity claims and general representations and warranties. There were no amounts released from the escrow to the sellers as of June 30, 2019. Revenue and net income from RIW were not material to the Company's consolidated revenue and "Income (loss) from continuing operations" during the three and six months ended June 30, 2019 and 2018. The Company did not present a proforma information summary for its consolidated results of operations for the three and six months ended June 30, 2018 as if the acquisition of RIW occurred on January 1, 2017 because such results were not material.

Discontinued Operations

Discontinued Operations	6 Months Ended
	Jun. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations On July 3, 2017, the Company completed the sale of Darex to Henkel for $1.06 billion in cash (the “Disposition”). The agreement with Henkel governing the Disposition (the “Amended Purchase Agreement”) provides for a series of delayed closings in certain non-U.S. jurisdictions for which sale proceeds were received on the July 3, 2017 closing date. The delayed closings implement the legal transfer of the Darex business in the delayed closing jurisdictions in accordance with local law. During the six months ended June 30, 2019 , the Company completed the delayed closing in Indonesia and recorded an after-tax gain on sale of $7.2 million . During the six months ended June 30, 2018, the Company completed the delayed closings in Argentina, Colombia, and Peru and recorded an after-tax gain of $10.3 million on the sale of the delayed close entities in these countries. The remaining delayed closing in Venezuela is expected to be completed during the year ended December 31, 2019. The results of the operations of the Darex business within the delayed close countries up to the time of their closings are reported as “(Loss) income from discontinued operations, net of income taxes” in the accompanying unaudited Consolidated Statements of Operations, with the exception of operations in Venezuela which were deconsolidated during 2017. As of December 31, 2018, a liability of $13.6 million related to the consideration received by GCP for the delayed closings was recognized in “Other current liabilities”. During the six months ended June 30, 2019 , GCP reduced the liability by $13.1 million which consisted of the sale proceeds received on July 3, 2017 for the delayed closing in Indonesia. The remaining liability of $0.5 million for the consideration received on July 3, 2017 related to the delayed closing in Venezuela is recorded in “Other current liabilities” as of June 30, 2019 . The following table includes a reconciliation of the gain on the sale of the Darex business related to delayed close entities recorded during the six months ended June 30, 2019 and 2018: Six Months Ended June 30, (In millions) 2019 2018 Net proceeds included in gain $ 12.7 $ 25.0 Net assets derecognized (3.1 ) (6.5 ) Gain recognized before income taxes 9.6 18.5 Tax effect of gain recognized (2.4 ) (8.2 ) Gain recognized after income taxes $ 7.2 $ 10.3 There were no sales of delayed close entities during the three months ended June 30, 2019 and 2018. In connection with the Disposition and related tax gain, as noted above, the Company recorded tax expense of $2.4 million and $8.2 million , respectively, within discontinued operations during the six months ended June 30, 2019 and 2018. The tax consequences of the Disposition are complex and the calculation of the provision is based on management’s best estimate using all readily accessible information. Based on the overall complexity of the calculation, management believes that there is a reasonable possibility that differences between the estimated tax provision and actual outcome may result within the next six months, which could have a material impact on the Company's results of operations. In connection with the Disposition, the Company and Henkel also entered into a Transition Services Agreement pursuant to which Henkel and the Company provided various services to each other in connection with the transition of the Darex business to Henkel. The services were related to real estate, information technology, accounts payable, payroll and other financial functions, as well as administrative services, and covered various periods up to 36 months following the closing date. The services substantially ended during the year ended December 31, 2018. The charges for such services generally allowed the servicing party to recover all out-of-pocket costs and expenses and were recorded in "Other income, net" on the accompanying unaudited Consolidated Statements of Operations. Under the Amended Purchase Agreement, GCP is required to indemnify Henkel for certain possible future tax liabilities. As of June 30, 2019 and December 31, 2018, GCP has recorded an indemnification payable of $0.9 million as a result of the Disposition. The following table sets forth the components of "Income from discontinued operations, net of income taxes" in the accompanying unaudited Consolidated Statements of Operations: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net sales $ — $ 5.9 $ — $ 11.6 Cost of goods sold — 5.6 — 12.7 Gross profit — 0.3 — (1.1 ) Selling, general and administrative expenses 0.6 1.5 0.9 3.3 Restructuring expenses and asset impairments 0.1 (0.3 ) 0.2 0.8 Gain on sale of business — — (9.6 ) (18.5 ) Other income, net (0.1 ) (2.9 ) — (3.1 ) (Loss) income from discontinued operations before income taxes (0.6 ) 2.0 8.5 16.4 Benefit from (provision for) income taxes 0.1 (0.7 ) (2.2 ) (7.9 ) (Loss) income from discontinued operations, net of income taxes $ (0.5 ) $ 1.3 $ 6.3 $ 8.5 The following table sets forth carrying amounts of the major classes of assets and liabilities of Darex classified as held for sale in the accompanying unaudited Consolidated Balance Sheets as of June 30, 2019 and December 31, 2018 : (In millions) June 30, 2019 December 31, 2018 Trade accounts receivable $ — $ 2.2 Inventories, net — 1.2 Current assets held for sale $ — $ 3.4 Properties and equipment, net — 0.2 Other assets 0.5 0.5 Non-current assets held for sale $ 0.5 $ 0.7 Underfunded and unfunded defined benefit pension plans — 0.4 Non-current liabilities held for sale $ — $ 0.4

Subsequent Event

Subsequent Event	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event Restructuring and Repositioning Plan (the "2019 Phase 2 Plan") On July 31, 2019, the Board approved a business restructuring and repositioning plan to further optimize the design and footprint of the Company's global organization, primarily with respect to its general administration and business support functions, and streamline cross-functional activities (the “2019 Phase 2 Plan”). The Company expects to incur total pre-tax costs in connection with the 2019 Phase 2 Plan of approximately $30 million to $35 million , of which approximately $23 million to $27 million represent restructuring costs and asset impairments, and approximately $7 million to $8 million represent repositioning costs. Approximately 90% of the estimated pre-tax restructuring costs represent employee severance and other employee-related costs, while the remaining 10% include other associated costs, including asset impairments. Repositioning costs primarily consist of consulting and recruitment services associated with the Company’s organizational realignment. Substantially all of the pre-tax restructuring costs, excluding asset impairments, and all of the pre-tax repositioning costs are expected to result in cash expenditures. Additionally, GCP expects to incur approximately $2 million of capital expenditures related to repositioning activities. The 2019 Phase 2 Plan is expected to result in the net reduction of approximately 8% to 10% of the Company's workforce. Substantially all of the restructuring actions under the 2019 Phase 2 Plan are expected to be completed by December 31, 2020.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	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 and six months ended June 30, 2019 are not necessarily indicative of the results of operations for the year ending December 31, 2019.
Discontinued Operations	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 June 30, 2019 and December 31, 2018, as discussed further in Note 19, "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	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 7, "Income Taxes".
Cash and Cash Equivalents	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 are presented at amortized cost and approximate fair value. Amounts are included within the "Cash and cash equivalents" in the accompanying unaudited Consolidated Balance Sheets.
Income Tax	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 7, "Income Taxes," for details regarding estimates used in accounting for income tax matters including unrecognized tax benefits.
Foreign Currency Transactions and Translation	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. The gains (losses) related to the remeasurement of these monetary net assets are included in "Other income, net" in the accompanying unaudited Consolidated Statements of Operations, and were immaterial for the three and six months ended June 30, 2019. The Argentina subsidiary's net sales were not material to the Company's consolidated net sales during the three and six months ended June 30, 2019 and its monetary net assets denominated in local currency were not material to GCP's consolidated total assets as of June 30, 2019 and December 31, 2018. Foreign Currency Transactions and Translation
Reclassifications	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 and Recently Issued Accounting Standards	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 and six months ended June 30, 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 it 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 June 30, 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 during the three and six months ended June 30, 2019 and cash flows during the six months ended June 30, 2019, as described in Note 6, "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 as of June 30, 2019, results of operations during the three and six months ended June 30, 2019, and cash flows during the six months ended June 30, 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 standard did not have a material impact on the Company's financial position, results of operations and cash flows upon adoption. 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 at inception 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 related to 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 and six months ended June 30, 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.

Revenue from Lessor Arrangeme_2

Revenue from Lessor Arrangements and Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2019
Revenues [Abstract]
Components of Operating Lease and Service Revenue	The following table summarizes the revenue recognized for these sales arrangements for the three and six months ended June 30, 2019 and 2018 and distinguishes between the lease and non-lease components: Three Months Ended June 30, Six Months Ended June 30, in millions 2019 2018 2019 2018 Lease revenue (1): Lease payments revenue $ 6.8 $ 6.8 $ 13.2 $ 13.1 Variable lease revenue 1.9 1.8 3.4 3.2 Total lease revenue $ 8.7 $ 8.6 $ 16.6 $ 16.3 Service revenue (2): Fixed fee revenue $ — $ — $ — $ 0.1 Variable fee revenue 1.2 1.1 2.2 2.0 Total service revenue $ 1.2 $ 1.1 $ 2.2 $ 2.1 Total revenue $ 9.9 $ 9.7 $ 18.8 $ 18.4 ________________________________ (1) Lease revenue consists of dispensers lease revenue, as well as an allocated portion of VERIFI ® fixed fees and variable slump management fees. Lease revenue is included within "Net Sales" in the accompanying unaudited Consolidated Statements of Operations. (2) Service revenue consists of an allocated portion of VERIFI ® fixed fees and variable slump management fees. Service revenue is included within "Net Sales" in the accompanying unaudited Consolidated Statements of Operations.

Inventories, net (Tables)

Inventories, net (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Schedule of Inventories	The following is a summary of inventories presented in the accompanying unaudited Consolidated Balance Sheets at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Raw materials $ 49.3 $ 46.0 In process 5.0 4.6 Finished products and other 62.8 59.9 Total inventories, net $ 117.1 $ 110.5

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net Investment Hedges in Balance Sheets	The following table summarizes the fair value of the Company’s derivative instruments designated as net investment hedges as of June 30, 2019: (In millions) As of June 30, 2019 Derivative liabilities (1) : Foreign exchange forward contracts $ 0.3 __________________________ (1) The fair value of derivative instruments is measured based on expected future cash flows discounted at market interest rates using observable market inputs and classified as Level 2 within the fair value hierarchy. Fair value of derivative liabilities is recorded within "Other Current Liabilities" and "Other Liabilities" in the accompanying unaudited Consolidated Balance Sheets.
Net Investment Hedges in Consolidated Statements of Operations and Comprehensive Income	The following table summarizes the amounts recorded in the Company's accompanying unaudited Consolidated Statements of Operations and Consolidated Statements of Comprehensive (Loss) Income related to forward contracts designated as net investment hedges for the three months ended June 30, 2019: (In millions) Three Months Ended June 30, 2019 "Other Income, net" Cumulative Translation Adjustments (1) Gains (losses) on foreign exchange forward contracts $ 0.1 $ (0.2 ) __________________________ (1) The amount is presented net of tax benefit of $0.1 million .

Debt and Other Borrowings (Tabl

Debt and Other Borrowings (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Components of Debt and Other Borrowings	The following is a summary of obligations under senior notes and other borrowings at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, 5.5% Senior Notes due in 2026, net of unamortized debt issuance costs of $4.1 million and $4.4 million, respectively, at June 30, 2019 and December 31, 2018 $ 345.9 $ 345.6 Revolving credit facility due 2023 (1) — — Other borrowings (2) 3.2 11.1 Total debt 349.1 356.7 Less: debt payable within one year 3.0 10.6 Debt payable after one year $ 346.1 $ 346.1 Weighted average interest rates on total debt obligations 5.5 % 5.7 % __________________________ (1) Represents borrowings under the Revolving Credit Facility with an aggregate available principal amount of $350.0 million as of June 30, 2019 and December 31, 2018 . (2) Represents borrowings of $1.9 million and $9.4 million , respectively, under various lines of credit and other borrowings, primarily by non-U.S. subsidiaries, as well as $1.3 million and $1.7 million , respectively, of finance lease obligations.
Principal Maturities of Debt and Finance Lease Obligations Outstanding	The principal maturities of debt obligations outstanding, net of debt issuance costs, were as follows at June 30, 2019 : (In millions) Year ending December 31, Amount 2019 $ 2.7 2020 0.5 2021 — 2022 — 2023 — Thereafter 345.9 Total debt $ 349.1
Carrying Amounts and Fair Values of Debt Instruments	The carrying amount and fair value of GCP's debt and other borrowings were as follows: June 30, 2019 December 31, 2018 (In millions) Carrying Amount Fair Value Carrying Amount Fair Value 5.5% Senior Notes due in 2026 $ 345.9 $ 355.6 $ 345.6 $ 344.2 Other borrowings 3.2 3.2 11.1 11.1 Total debt $ 349.1 $ 358.8 $ 356.7 $ 355.3

Lessee Arrangements (Tables)

Lessee Arrangements (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Lease Expense	The following table summarizes components of lease expense for the three and six months ended June 30, 2019 : (In millions) Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense $ 3.1 $ 6.4 Variable lease expense 1.3 2.5 Short-term lease expense 0.5 0.9 Total lease expense $ 4.9 $ 9.8 The following table summarizes supplemental cash flow information related to leases during the six months ended June 30, 2019 : (In millions) Amount Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 6.4 Operating lease right of use assets obtained in exchange for new lease obligations: Upon adoption of Topic 842 $ 40.8 During the six months ended June 30, 2019 2.8 Total $ 43.6
Lease Liability Maturities	The following table summarizes lease liability maturities as of June 30, 2019 : (In millions) Year ending December 31, Amount 2019 $ 5.9 2020 8.9 2021 5.3 2022 3.0 2023 2.1 Thereafter 26.7 Total undiscounted lease payments 51.9 Less: imputed interest (15.3 ) Present value of lease payments 36.6 Less: operating lease obligations payable within one year (9.3 ) Long-term operating lease obligations $ 27.3
Future Minimum Noncancelable Payments	As of December 31, 2018, future minimum noncancelable payments for operating leases are as follows: (In millions) Year ending December 31, Amount 2019 $ 12.1 2020 8.3 2021 4.6 2022 2.6 2023 1.9 Thereafter 28.1 Total $ 57.6

Pension Plans and Other Postr_2

Pension Plans and Other Postretirement Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Net Funded Status of Over-Funded, Underfunded, and Unfunded Pension Plans	The following table presents the funded status of GCP's overfunded, underfunded and unfunded defined pension plans: (In millions) June 30, 2019 December 31, 2018 Overfunded defined benefit pension plans $ 22.3 $ 22.5 Underfunded defined benefit pension plans (26.7 ) (24.2 ) Unfunded defined benefit pension plans (23.8 ) (23.9 ) Total underfunded and unfunded defined benefit pension plans (50.5 ) (48.1 ) Pension liabilities included in other current liabilities (1.3 ) (1.3 ) Net funded status $ (29.5 ) $ (26.9 )
Components of Net Periodic Benefit Cost (Income)	Components of Net Periodic Benefit Cost The components of GCP's net periodic benefit cost for the three and six months ended June 30, 2019 and 2018 are as follows: Three Months Ended June 30, 2019 2018 Pension Pension (In millions) U.S. Non-U.S. U.S. Non-U.S. Service cost $ 1.7 $ 0.6 $ 2.0 $ 0.8 Interest cost 1.5 1.3 1.4 1.4 Expected return on plan assets (1.6 ) (1.5 ) (1.9 ) (1.8 ) Mark-to-market adjustment — — — (0.3 ) Gain on curtailments, settlements, and terminations — — — (0.1 ) Net periodic benefit cost (1) $ 1.6 $ 0.4 $ 1.5 $ — Six Months Ended June 30, 2019 2018 Pension Pension (In millions) U.S. Non-U.S. U.S. Non-U.S. Service cost $ 3.2 $ 1.3 $ 4.0 $ 1.6 Interest cost 2.9 2.7 2.8 2.8 Expected return on plan assets (3.2 ) (3.0 ) (3.8 ) (3.6 ) Mark-to-market adjustment — — — (0.3 ) Gain on curtailments, settlements, and terminations — — — (0.1 ) Net periodic benefit cost (income) (1)(2) $ 2.9 $ 1.0 $ 3.0 $ 0.4 ________________________________ (1) Service cost component of net periodic benefit cost is included in "Selling, general and administrative expenses" and "Cost of goods sold" in the accompanying unaudited Consolidated Statements of Operations. All other components of net periodic benefit cost are presented in "Other income, net," within the accompanying unaudited Consolidated Statements of Operations. (2) During the three and six months ended June 30, 2019, the Company recognized a curtailment gain of $0.0 million and $0.2 million , respectively, within the gain on sale of Indonesia related to its delayed closing as a part of Darex divestiture. Please refer to Note 19, "Discontinued Operations" for further information.

Other Balance Sheet Accounts (T

Other Balance Sheet Accounts (Tables)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Other Current Assets	The following is a summary of other current assets at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Other Current Assets: Non-trade receivables $ 19.8 $ 25.0 Prepaid expenses and other current assets 12.4 9.2 Income taxes receivable 11.8 10.4 Total other current assets $ 44.0 $ 44.6
Schedule of Other Current Liabilities	The following is a summary of other current liabilities at June 30, 2019 and December 31, 2018 : (In millions) June 30, December 31, Other Current Liabilities: Accrued customer volume rebates $ 23.6 $ 35.3 Accrued compensation (1) 13.4 16.4 Income taxes payable 12.1 17.2 Accrued interest 4.1 4.0 Pension liabilities 1.3 1.3 Restructuring liability 3.8 10.2 Other accrued liabilities (2) 46.9 61.1 Total other current liabilities $ 105.2 $ 145.5 ________________________________ (1) Accrued compensation presented in the table above includes salaries and wages, as well as estimated current amounts due under the annual and long-term employee incentive programs. (2) Other accrued liabilities presented in the table above as of June 30, 2019 and December 31, 2018 include $0.5 million and $13.6 million , respectively, representing the current portion of the liability related to the delayed closings associated with the Company's divestiture of Darex, as discussed in Note 19, "Discontinued Operations."

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Equity Activity	The following table summarizes the Company’s stockholders' equity activity during the three months ended June 30, 2019 and 2018. Common Stock Treasury Stock (In millions) Number of Shares Par Value Number of Shares Cost Additional Paid-in Capital Accumulated Earnings Accumulated Other Comprehensive Loss Noncontrolling Interests Total Stockholders' Equity Balance, March 31, 2018 72.2 $ 0.7 0.2 $ (4.1 ) $ 35.3 $ 542.1 $ (71.4 ) $ 1.9 $ 504.5 Net (loss) income — — — — — (27.9 ) — 0.1 (27.8 ) Issuance of common stock in connection with stock plans 0.1 — — — — — — — — Share-based compensation — — — — 3.9 — — — 3.9 Exercise of stock options 0.1 — — — 1.6 — — — 1.6 Share repurchases (1) — — — (0.6 ) — — — — (0.6 ) Other comprehensive loss — — — — — — (33.0 ) — (33.0 ) Balance, June 30, 2018 72.4 $ 0.7 0.2 $ (4.7 ) $ 40.8 $ 514.2 $ (104.4 ) $ 2.0 $ 448.6 Balance, March 31, 2019 72.9 $ 0.7 0.3 $ (8.0 ) $ 44.6 $ 585.3 $ (116.8 ) $ 2.2 $ 508.0 Net income — — — — — 2.6 — — 2.6 Issuance of common stock in connection with stock plans (2) — — — — — — — — — Share-based compensation — — — — 3.9 — — — 3.9 Exercise of stock options 0.1 — — — 1.7 — — — 1.7 Share repurchases (1) — — — — — — — — — Other comprehensive loss — — — — — — (3.9 ) — (3.9 ) Balance, June 30, 2019 73.0 $ 0.7 0.3 $ (8.0 ) $ 50.2 $ 587.9 $ (120.7 ) $ 2.2 $ 512.3 ________________________________ (1) During the three months ended June 30, 2018, GCP withheld and retained approximately 22,000 shares of Company common stock in a non-cash transaction with a cost of $0.6 million in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the three months ended June 30, 2019, GCP withheld and retained approximately 300 shares of Company common stock in a non-cash transaction with a cost which was immaterial. During the three months ended June 30, 2018, cash payments for such tax withholding obligations were $0.6 million . (2) The par value of shares issued is not included in the table due to rounding.

Restructuring and Repositioni_2

Restructuring and Repositioning Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Expenses	The following restructuring expenses and asset impairment charges were incurred under the 2018 and 2017 Plans and other plans during each period: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Severance and other employee costs $ 0.2 $ (0.9 ) 0.5 $ (0.7 ) Asset impairments 3.8 — 4.0 0.4 Other associated costs 0.5 — 0.7 — Total restructuring expenses and asset impairments $ 4.5 $ (0.9 ) $ 5.2 $ (0.3 ) Less: restructuring expenses and asset impairments reflected in discontinued operations 0.1 (0.3 ) 0.2 0.8 Total restructuring expenses and asset impairments from continuing operations $ 4.4 $ (0.6 ) $ 5.0 $ (1.1 ) GCP incurred restructuring expenses and asset impairment charges related to its two operating segments and Corporate function as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 SCC $ 1.3 $ (0.6 ) $ 1.9 $ (1.0 ) SBM 3.2 0.1 3.2 (0.4 ) Corporate (0.1 ) (0.1 ) (0.1 ) 0.3 Total restructuring expenses and asset impairments from continuing operations $ 4.4 $ (0.6 ) $ 5.0 $ (1.1 ) Restructuring expenses and asset impairments reflected in discontinued operations 0.1 (0.3 ) 0.2 0.8 Total restructuring expenses and asset impairments $ 4.5 $ (0.9 ) $ 5.2 $ (0.3 )
Schedule of Restructuring Liability	The following table summarizes the Company’s restructuring liability activity: 2018 Plan 2017 Plan (In millions) Severance and other employee costs Facility exit costs Other Costs Severance and other employee costs Other plans Total Balance, December 31, 2018 $ 7.7 $ 0.2 $ — $ 1.8 $ 0.5 $ 10.2 Expense (1) 0.4 — 0.1 — (0.1 ) 0.4 Payments (2.2 ) (0.1 ) — (1.5 ) (0.2 ) (4.0 ) Impact of foreign currency and other (0.1 ) — — — (0.1 ) (0.2 ) Balance, March 31, 2019 $ 5.8 $ 0.1 $ 0.1 $ 0.3 $ 0.1 $ 6.4 Expense (1) — — 0.2 (0.1 ) 0.3 0.4 Payments (2.3 ) (0.1 ) (0.2 ) (0.1 ) (0.4 ) (3.1 ) Impact of foreign currency and other — — — 0.1 — 0.1 Balance, June 30, 2019 $ 3.5 $ — $ 0.1 $ 0.2 $ — $ 3.8 ________________________________ (1) Asset impairment charges of $ 3.8 million and $4.0 million , respectively, for the three and six months ended June 30, 2019 related to the 2018 and 2017 Plans are primarily recorded as a reduction to "Properties and equipment, net" in the accompanying unaudited Consolidated Balance Sheets. During the three and six months ended June 30, 2019, asset impairment charges of $0.7 million and $0.9 million , respectively, were attributable to the SCC segment and $3.1 million and $3.1 million , respectively, were attributable to the SBM segment. Other associated costs attributable to SCC, of $0.3 million and $0.4 million , respectively, for the three and six months ended June 30, 2019 related to the 2018 Plan are recorded as a reduction to "Inventories, net" in the accompanying unaudited Consolidated Balance Sheets. These expenses are not recorded to the restructuring liability and therefore, are not included in the table above.

Other Comprehensive Loss (Table

Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Schedule of Pre-tax, Tax, and After-tax Components of Other Comprehensive Income (Loss)	The following tables present the pre-tax, tax, and after-tax components of GCP's other comprehensive loss for the three and six months ended June 30, 2019 and 2018 : Three Months Ended June 30, 2019 (In millions) Pre-Tax Amount Tax Expense After-Tax Amount Currency translation adjustments (1) $ (3.9 ) $ — $ (3.9 ) Other comprehensive loss attributable to GCP shareholders $ (3.9 ) $ — $ (3.9 ) Six Months Ended June 30, 2019 (In millions) Pre-Tax Amount Tax Benefit After-Tax Amount Currency translation adjustments (1) $ (0.6 ) $ — $ (0.6 ) Loss from hedging activities (0.1 ) — (0.1 ) Other comprehensive loss attributable to GCP shareholders $ (0.7 ) $ — $ (0.7 ) Three Months Ended June 30, 2018 (In millions) Pre-Tax Amount Tax Expense After-Tax Amount Defined benefit pension and other postretirement plans $ (0.8 ) $ 0.2 $ (0.6 ) Currency translation adjustments (1) (32.5 ) — (32.5 ) Gain from hedging activities 0.1 — 0.1 Other comprehensive loss attributable to GCP shareholders $ (33.2 ) $ 0.2 $ (33.0 ) Six Months Ended June 30, 2018 (In millions) Pre-Tax Amount Tax Benefit After-Tax Amount Defined benefit pension and other postretirement plans $ (0.8 ) $ 0.2 $ (0.6 ) Currency translation adjustments (1) (18.2 ) — (18.2 ) Gain from hedging activities 0.1 — 0.1 Other comprehensive loss attributable to GCP shareholders $ (18.9 ) $ 0.2 $ (18.7 ) __________________________ (1) Currency translation adjustments did not have a corresponding tax effect.
Schedule of Changes of Accumulated Other Comprehensive Income (Loss), Net of Tax	The following tables present the changes in accumulated other comprehensive loss, net of tax, for the six months ended June 30, 2019 and 2018 : (In millions) Defined Benefit Pension and Other Postretirement Plans Currency Translation Adjustments Hedging Activities Total Balance, December 31, 2018 $ (2.2 ) $ (117.8 ) $ — $ (120.0 ) Current-period other comprehensive loss — (0.6 ) (0.1 ) (0.7 ) Balance, June 30, 2019 $ (2.2 ) $ (118.4 ) $ (0.1 ) $ (120.7 ) (In millions) Defined Benefit Pension and Other Postretirement Plans Currency Translation Adjustments Hedging Activities Total Balance, December 31, 2017 $ 0.4 $ (86.0 ) $ (0.1 ) $ (85.7 ) Current-period other comprehensive (loss) income (0.6 ) (18.2 ) 0.1 (18.7 ) Balance, June 30, 2018 $ (0.2 ) $ (104.2 ) $ — $ (104.4 )

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Assumptions for Estimating the Fair Value of Stock Options	The following assumptions were utilized in the Black-Scholes option pricing model for estimating the fair value of GCP's stock options granted during the six months ended June 30, 2019 and 2018 : Six Months Ended June 30, Assumptions used to calculate expense for stock options: 2019 2018 Risk-free interest rate 2.35 -2.64% 2.68 - 2.90% Average life of options (years) 5.5 - 6.5 5.5 - 6.5 Volatility 28.02 - 28.59% 27.91 - 30.65% Dividend yield — — Weighted average fair value per stock option $8.74 $11.02
Summary of Stock Option Activity	The following table sets forth information relating to stock options denominated in GCP stock during the six months ended June 30, 2019 : Stock Option Activity Number Of Weighted Weighted Aggregated Outstanding, December 31, 2018 1,518 21.18 3.75 $ 7,145 Options exercised (267 ) 18.66 Options forfeited/expired/canceled (27 ) 27.66 Options granted 262 26.65 Outstanding, June 30, 2019 1,486 22.47 4.21 $ 3,806 Exercisable, June 30, 2019 1,009 19.90 3.13 $ 3,806 Vested and expected to vest, June 30, 2019 1,468 22.42 4.18 $ 3,806
Summary of Restricted Stock Units Award Activity	The following table sets forth the RSU activity for the six months ended June 30, 2019 : RSU Activity Number Of Weighted Outstanding, December 31, 2018 363 $ 22.76 RSUs settled (237 ) 19.90 RSUs forfeited (8 ) 28.87 RSUs granted 133 26.91 RSUs outstanding, June 30, 2019 251 $ 27.45 Expected to vest as of June 30, 2019 242 $ 27.47
Schedule of Assumptions for Estimating the Fair Value of PBUs	The following table summarizes the assumptions used in the Monte Carlo simulations for estimating the grant date fair values of PBUs granted during the six months ended June 30, 2019 and 2018: Six Months Ended June 30, Assumptions used to calculate expense for PBUs: 2019 2018 Expected Term (Remaining Performance Period) 2.86 2.86 Expected volatility 28.46% 28.56% Risk-free interest rate 2.48% 2.38% Expected dividends — — Correlation coefficient 54.81% 38.98% Average correlation coefficient of constituents 57.09% 39.96%

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Reconciliation of the Numerators and Denominators Used in Calculating Basic and Diluted Earnings Per Share	The following table sets forth a reconciliation of the numerators and denominators used in calculating basic and diluted earnings (loss) per share: Three Months Ended June 30, Six Months Ended June 30, (In millions, except per share amounts) 2019 2018 2019 2018 Numerators Income (loss) from continuing operations attributable to GCP shareholders $ 3.1 $ (29.2 ) $ 17.7 $ (43.0 ) (Loss) income from discontinued operations, net of income taxes (0.5 ) 1.3 6.3 8.5 Net income (loss) attributable to GCP shareholders $ 2.6 $ (27.9 ) $ 24.0 $ (34.5 ) Denominators Weighted average common shares—basic calculation 72.6 72.1 72.5 72.0 Dilutive effect of employee stock awards (1) 0.4 — 0.4 — Weighted average common shares—diluted calculation 73.0 72.1 72.9 72.0 Basic earnings (loss) per share Income (loss) from continuing operations attributable to GCP shareholders $ 0.04 $ (0.40 ) $ 0.24 $ (0.60 ) (Loss) income from discontinued operations, net of income taxes $ (0.01 ) $ 0.02 $ 0.09 $ 0.12 Net income (loss) attributable to GCP shareholders (2) $ 0.04 $ (0.39 ) $ 0.33 $ (0.48 ) Diluted earnings (loss) per share (1) Income (loss) from continuing operations attributable to GCP shareholders $ 0.04 $ (0.40 ) $ 0.24 $ (0.60 ) (Loss) income from discontinued operations, net of income taxes $ (0.01 ) $ 0.02 $ 0.09 $ 0.12 Net income (loss) attributable to GCP shareholders (2) $ 0.04 $ (0.39 ) $ 0.33 $ (0.48 ) ________________________________ (1) Dilutive effect not applicable to periods in which GCP generated a loss from continuing operations. (2) Amounts may not sum due to rounding.
Schedule of Dilutive Effect of Options and RSUs	The following table sets forth the weighted average options and RSUs excluded from the computation of dilutive shares and diluted loss per share that would've been reflected in the "Dilutive effect of employee stock awards" line in the table above: Three Months Ended June 30, Six Months Ended June 30, (In millions of shares) 2019 2018 2019 2018 Dilutive effect: (1) Options N/A 0.5 N/A 0.5 RSUs N/A 0.2 N/A 0.2 __________________________ (1) N/A - Dilutive effect is included in computation of diluted earnings per share under the treasury stock method for periods in which GCP generated income from continuing operations.

Operating Segment and Geograp_2

Operating Segment and Geographic Information (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Schedule of Operating Segment Data	The following table presents information related to GCP's operating segments: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net Sales Specialty Construction Chemicals $ 150.4 $ 175.0 $ 282.1 $ 322.0 Specialty Building Materials 111.8 127.8 206.2 231.0 Total net sales $ 262.2 $ 302.8 $ 488.3 $ 553.0 Segment Operating Income Specialty Construction Chemicals segment operating income $ 14.2 $ 12.6 $ 22.1 $ 18.5 Specialty Building Materials segment operating income 22.3 31.8 38.2 49.9 Total segment operating income $ 36.5 $ 44.4 $ 60.3 $ 68.4
Reconciliation of Operating Segment Data to Financial Statements	Total segment operating income for the three and six months ended June 30, 2019 and 2018 , is reconciled below to " Income (loss) from continuing operations before income taxes " presented in the accompanying unaudited Consolidated Statements of Operations: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Total segment operating income $ 36.5 $ 44.4 $ 60.3 $ 68.4 Corporate costs (9.4 ) (8.6 ) (19.3 ) (17.5 ) Certain pension costs (2.0 ) (1.9 ) (3.9 ) (3.8 ) Other costs (1.1 ) — (3.6 ) — Repositioning expenses (5.8 ) (1.2 ) (11.2 ) (2.1 ) Restructuring expenses and asset impairments (4.4 ) 0.6 (5.0 ) 1.1 Pension MTM adjustment and other related costs, net — (0.9 ) — (0.9 ) Gain on termination and curtailment of pension and other postretirement plans — 0.1 — 0.1 Third-party and other acquisition-related costs — (0.8 ) (0.1 ) (1.6 ) Amortization of acquired inventory fair value adjustment — (0.2 ) — (0.2 ) Legacy product, environmental and other claims (0.1 ) — (0.1 ) — Net income attributable to noncontrolling interests — 0.1 0.2 0.2 Interest expense, net (1) (4.9 ) (66.0 ) (10.1 ) (78.3 ) Income (loss) from continuing operations before income taxes $ 8.8 $ (34.4 ) $ 7.2 $ (34.6 ) __________________________ (1) During the three and six months ended June 30, 2018, "Interest expense, net" includes a loss of $59.8 million as a result of a debt refinancing transaction completed on April 10, 2018. Please refer to Note 6, "Debt and Other Borrowings," in the Notes to the Consolidated Financial Statements included in Item 8 "Financial Statements and Supplementary Data" of the Annual Report on Form 10‑K.
Net Sales by Geographic Area	The table below presents information related to the geographic areas in which GCP operates. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net Sales United States $ 126.6 $ 141.1 $ 234.4 $ 258.0 Canada and Other 9.2 8.2 14.9 14.3 Total North America 135.8 149.3 249.3 272.3 Europe Middle East Africa 52.3 69.2 98.7 127.5 Asia Pacific 58.9 65.7 109.6 117.7 Latin America 15.2 18.6 30.7 35.5 Total $ 262.2 $ 302.8 $ 488.3 $ 553.0
Long-Lived Assets by Geographic Area	The following table sets forth certain long-lived asset information related to the geographic areas in which GCP operates: (In millions) As of June 30, 2019 Operating lease right-of-use assets United States $ 12.9 Canada 0.2 Total North America 13.1 Europe, Middle East, and Africa 12.9 Asia Pacific 9.1 Latin America 1.2 Total $ 36.3 Operating lease right-of-use assets Specialty Construction Chemicals $ 18.9 Specialty Building Materials 14.0 Corporate 3.4 Total $ 36.3

Discontinued Operations (Tables

Discontinued Operations (Tables)	6 Months Ended
	Jun. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Reconciliation of Gain on Disposal	The following table includes a reconciliation of the gain on the sale of the Darex business related to delayed close entities recorded during the six months ended June 30, 2019 and 2018: Six Months Ended June 30, (In millions) 2019 2018 Net proceeds included in gain $ 12.7 $ 25.0 Net assets derecognized (3.1 ) (6.5 ) Gain recognized before income taxes 9.6 18.5 Tax effect of gain recognized (2.4 ) (8.2 ) Gain recognized after income taxes $ 7.2 $ 10.3
Financial Results and Other Effects Related to Discontinued Operations	The following table sets forth the components of "Income from discontinued operations, net of income taxes" in the accompanying unaudited Consolidated Statements of Operations: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2019 2018 2019 2018 Net sales $ — $ 5.9 $ — $ 11.6 Cost of goods sold — 5.6 — 12.7 Gross profit — 0.3 — (1.1 ) Selling, general and administrative expenses 0.6 1.5 0.9 3.3 Restructuring expenses and asset impairments 0.1 (0.3 ) 0.2 0.8 Gain on sale of business — — (9.6 ) (18.5 ) Other income, net (0.1 ) (2.9 ) — (3.1 ) (Loss) income from discontinued operations before income taxes (0.6 ) 2.0 8.5 16.4 Benefit from (provision for) income taxes 0.1 (0.7 ) (2.2 ) (7.9 ) (Loss) income from discontinued operations, net of income taxes $ (0.5 ) $ 1.3 $ 6.3 $ 8.5 The following table sets forth carrying amounts of the major classes of assets and liabilities of Darex classified as held for sale in the accompanying unaudited Consolidated Balance Sheets as of June 30, 2019 and December 31, 2018 : (In millions) June 30, 2019 December 31, 2018 Trade accounts receivable $ — $ 2.2 Inventories, net — 1.2 Current assets held for sale $ — $ 3.4 Properties and equipment, net — 0.2 Other assets 0.5 0.5 Non-current assets held for sale $ 0.5 $ 0.7 Underfunded and unfunded defined benefit pension plans — 0.4 Non-current liabilities held for sale $ — $ 0.4

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)segment	Jun. 30, 2018USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)	Jul. 03, 2017USD ($)
Class of Stock [Line Items]
Number of operating segments | segment			2
Operating lease right-of-use assets	$ 36.3		$ 36.3			$ 0
Operating lease obligations	36.6		36.6
ASU 2016-02 - Topic 842
Class of Stock [Line Items]
Operating lease right-of-use assets					$ 40.8
Operating lease obligations					$ 40.9
Other income, net
Class of Stock [Line Items]
Net foreign currency transaction and remeasurement losses	0	$ (0.4)	0	$ (0.7)
Loss recognized related to remeasurement of assets, highly inflationary economy	$ 0		$ 0
Disposed of by Sale | Darex
Class of Stock [Line Items]
Consideration received							$ 1,060

Revenue from Lessor Arrangeme_3

Revenue from Lessor Arrangements and Contracts with Customers - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Revenues [Abstract]
Lease component, lease term (or less)	30 days
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 188.4	$ 198.6
Property, Plant and Equipment [Line Items]
Revenue, remaining performance obligation	$ 5.2
Revenue, remaining performance obligation, expected timing of satisfaction	one to five years
Trade accounts receivable, lease revenue
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade accounts receivable	$ 5.5	$ 4.7
Dispensers
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
VERIFI equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years

Revenue from Lessor Arrangeme_4

Revenue from Lessor Arrangements and Contracts with Customers - Operating Lease and Service Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Lease revenue:
Total revenue	$ 262.2	$ 302.8	$ 488.3	$ 553
VERIFI Sales Arrangements
Lease revenue:
Lease payments revenue	6.8	6.8	13.2	13.1
Variable lease revenue	1.9	1.8	3.4	3.2
Total lease revenue	8.7	8.6	16.6	16.3
Total service revenue	1.2	1.1	2.2	2.1
Total revenue	9.9	9.7	18.8	18.4
VERIFI Sales Arrangements | Fixed fee revenue
Lease revenue:
Total service revenue	0	0	0	0.1
VERIFI Sales Arrangements | Variable fee revenue
Lease revenue:
Total service revenue	$ 1.2	$ 1.1	$ 2.2	$ 2

Inventories, net - Schedule of

Inventories, net - Schedule of Inventory (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Raw materials	$ 49.3	$ 46
In process	5	4.6
Finished products and other	62.8	59.9
Total inventories, net	$ 117.1	$ 110.5

Inventories, net - Narrative (D

Inventories, net - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Inventory [Line Items]
Finished products and other	$ 62.8	$ 59.9
Finished Products Purchased
Inventory [Line Items]
Finished products and other	$ 13.4	$ 12.9

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details)	3 Months Ended
	Jun. 30, 2019EUR (€)derivative_instrument
Derivative [Line Items]
Number of instruments entered | derivative_instrument	4
Forward contracts
Derivative [Line Items]
Aggregate notional amount	€ 40,000,000
Forward contract maturing 2020
Derivative [Line Items]
Aggregate notional amount	10,000,000
Forward contract maturing 2021
Derivative [Line Items]
Aggregate notional amount	10,000,000
Forward contract maturing 2022
Derivative [Line Items]
Aggregate notional amount	10,000,000
Forward contract maturing 2023
Derivative [Line Items]
Aggregate notional amount	€ 10,000,000

Derivative Instruments - Net In

Derivative Instruments - Net Investment Hedges in Balance Sheets (Details) $ in Millions	Jun. 30, 2019USD ($)
Forward contracts
Derivative [Line Items]
Derivative liabilities	$ 0.3

Derivative Instruments - Net _2

Derivative Instruments - Net Investment Hedges in Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative [Line Items]
Gains (losses) on foreign exchange forward contracts - cumulative translation adjustments, net of tax benefit	$ (3.9)	$ (32.5)	$ (0.6)	$ (18.2)
Forward contracts
Derivative [Line Items]
Gains (losses) on foreign exchange forward contracts - other income, net	0.1
Gains (losses) on foreign exchange forward contracts - cumulative translation adjustments, net of tax benefit	(0.2)
Gains (losses) on foreign exchange forward contracts - cumulative translation adjustments, tax benefit	$ 0.1

Debt and Other Borrowings - Com

Debt and Other Borrowings - Components of Debt (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total debt	$ 349,100,000	$ 356,700,000
Less: debt payable within one year	3,000,000	10,600,000
Debt payable after one year	$ 346,100,000	$ 346,100,000
Weighted average interest rates on total debt obligations	5.50%	5.70%
Finance lease obligations	$ 1,300,000	$ 1,700,000
Senior Notes | 5.5% Senior Notes due in 2026
Debt Instrument [Line Items]
Total debt	$ 345,900,000	345,600,000
Stated interest rate	5.50%
Unamortized debt issuance cost	$ 4,100,000	4,400,000
Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Total debt	0	0
Unamortized debt issuance cost	3,600,000	4,100,000
Aggregate available principal amount	350,000,000	350,000,000
Other borrowings
Debt Instrument [Line Items]
Total debt	3,200,000	11,100,000
Lines of credit and other borrowings
Debt Instrument [Line Items]
Total debt	$ 1,900,000	$ 9,400,000

Debt and Other Borrowings - Pri

Debt and Other Borrowings - Principal Maturities of Debt Outstanding (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2019	$ 2.7
2020	0.5
2021	0
2022	0
2023	0
Thereafter	345.9
Total debt	$ 349.1	$ 356.7

Debt and Other Borrowings - Nar

Debt and Other Borrowings - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Senior Notes | 5.5% Senior Notes due in 2026
Debt Instrument [Line Items]
Stated interest rate	5.50%	5.50%
Aggregate principal amount	$ 350,000,000	$ 350,000,000
Interest payment		9,600,000
Unamortized debt issuance cost	4,100,000	4,100,000	$ 4,400,000
Line of credit | Revolving credit facility
Debt Instrument [Line Items]
Outstanding borrowings	0	0	0
Available credit	345,000,000	345,000,000
Interest payments	0
Unamortized debt issuance cost	3,600,000	$ 3,600,000	$ 4,100,000
Line of credit | Revolving credit facility | Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.50%
Line of credit | Revolving credit facility | Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		1.00%
Line of credit | Revolving credit facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		1.50%
Line of credit | Revolving credit facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Line of credit | Letter of credit
Debt Instrument [Line Items]
Outstanding borrowings	$ 5,000,000	$ 5,000,000

Debt and Other Borrowings - Car

Debt and Other Borrowings - Carrying Amounts and Fair Values of Debt Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
5.5% Senior Notes due in 2026 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate	5.50%
Carrying Amount
Debt Instrument [Line Items]
Long-term debt, fair value	$ 349.1	$ 356.7
Carrying Amount | Other Borrowings
Debt Instrument [Line Items]
Long-term debt, fair value	3.2	11.1
Carrying Amount | 5.5% Senior Notes due in 2026 | Senior Notes
Debt Instrument [Line Items]
Long-term debt, fair value	345.9	345.6
Fair Value
Debt Instrument [Line Items]
Long-term debt, fair value	358.8	355.3
Fair Value | Other Borrowings
Debt Instrument [Line Items]
Long-term debt, fair value	3.2	11.1
Fair Value | 5.5% Senior Notes due in 2026 | Senior Notes
Debt Instrument [Line Items]
Long-term debt, fair value	$ 355.6	$ 344.2

Lessee Arrangements - Narrative

Lessee Arrangements - Narrative (Details)	Jun. 30, 2019
Leases [Abstract]
Weighted average discount rate for operating leases	5.21%
Operating leases, lease term (up to)	8 years 2 months 12 days
Operating leases, renewal term (up to)	32 years
Operating leases, weighted average remaining lease term	15 years

Lessee Arrangements - Lease Exp

Lessee Arrangements - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease expense	$ 3.1	$ 6.4
Variable lease expense	1.3	2.5
Short-term lease expense	0.5	0.9
Total lease expense	$ 4.9	$ 9.8

Lessee Arrangements - Lease Lia

Lessee Arrangements - Lease Liability Maturities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Leases [Abstract]
2019	$ 5.9
2020	8.9
2021	5.3
2022	3
2023	2.1
Thereafter	26.7
Total undiscounted lease payments	51.9
Less: imputed interest	(15.3)
Present value of lease payments	36.6
Less: operating lease obligations payable within one year	(9.3)	$ 0
Long-term operating lease obligations	$ 27.3	$ 0

Lessee Arrangements - Supplemen

Lessee Arrangements - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	Jan. 01, 2019	Jun. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases		$ 6.4
Operating lease right of use assets obtained in exchange for new lease obligations:
Upon adoption of Topic 842		43.6
ASU 2016-02 - Topic 842
Operating lease right of use assets obtained in exchange for new lease obligations:
Upon adoption of Topic 842	$ 40.8	$ 2.8

Lessee Arrangements - Future Mi

Lessee Arrangements - Future Minimum Noncancelable Payments (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 12.1
2020	8.3
2021	4.6
2022	2.6
2023	1.9
Thereafter	28.1
Total	$ 57.6

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 5.7	$ (5.3)	$ (10.7)	$ 8.2
Effective tax rate	64.80%	15.40%	148.60%	23.70%
Transition Tax liability					$ 20.2
Transition Tax, tax benefit from the release of an uncertain tax position	$ 20.2		$ 20.2
Tax Act, measurement period adjustment, income tax expense (benefit)			3.6	$ 12.5
Tax Act, measurement period adjustment, long-term tax payable, income tax expense	3.4
Tax Act, measurement period adjustment, short-term tax payable, income tax expense	0.2
Transition Tax obligation	41.1		41.1
Change in valuation allowance			0.5	1
Discontinued operations | Darex
Operating Loss Carryforwards [Line Items]
Provision (benefit) for income taxes of discontinued operations	$ (0.1)	$ 0.7	$ 2.2	$ 7.9

Pension Plans and Other Postr_3

Pension Plans and Other Postretirement Benefit Plans - Net Funded Status of Over-Funded, Underfunded, and Unfunded Pension Plans (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Pension plans and other postretirement benefit plans
Overfunded defined benefit pension plans	$ 22.3	$ 22.5
Underfunded and unfunded defined benefit pension plans	(50.5)	(48.1)
Pension Plans
Pension plans and other postretirement benefit plans
Overfunded defined benefit pension plans	22.3	22.5
Underfunded and unfunded defined benefit pension plans	(50.5)	(48.1)
Pension liabilities included in other current liabilities	(1.3)	(1.3)
Net funded status	(29.5)	(26.9)
Underfunded defined benefit pension plans | Pension Plans
Pension plans and other postretirement benefit plans
Underfunded and unfunded defined benefit pension plans	(26.7)	(24.2)
Unfunded defined benefit pension plans | Pension Plans
Pension plans and other postretirement benefit plans
Underfunded and unfunded defined benefit pension plans	$ (23.8)	$ (23.9)

Pension Plans and Other Postr_4

Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost			$ 0.1
Curtailment gain			0	$ 0.1
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 1.7	$ 2	3.2	4
Interest cost	1.5	1.4	2.9	2.8
Expected return on plan assets	(1.6)	(1.9)	(3.2)	(3.8)
Mark-to-market adjustment	0	0	0	0
Gain on curtailments, settlements, and terminations	0	0	0	0
Net periodic benefit cost (income)	1.6	1.5	2.9	3
Non-U.S.
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.6	0.8	1.3	1.6
Interest cost	1.3	1.4	2.7	2.8
Expected return on plan assets	(1.5)	(1.8)	(3)	(3.6)
Mark-to-market adjustment	0	(0.3)	0	(0.3)
Gain on curtailments, settlements, and terminations	0	(0.1)	0	(0.1)
Net periodic benefit cost (income)	0.4	$ 0	1	$ 0.4
Discontinued operations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Curtailment gain	$ 0		$ 0.2

Pension Plans and Other Postr_5

Pension Plans and Other Postretirement Benefit Plans - Narrative (Details) - USD ($) $ in Millions	Jan. 01, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Pension plans and other postretirement benefit plans
Defined benefit plan expense				$ 0.1
Defined contribution plan, percentage that the employer contributes of employee contributions under 401(k) plan	100.00%			100.00%
Defined contribution plan, maximum percentage of employee compensation match by employer to defined contribution plan				6.00%
Defined contribution plan, additional maximum percentage of employee compensation match by employer to defined contribution plan	2.00%
Defined contribution plan, vesting requirement	3 years
Defined contribution plan, costs		$ 1.2	$ 1.5	$ 2.5	$ 2.5
Postretirement Health Care
Pension plans and other postretirement benefit plans
Long-term liability		1.8		1.8		$ 1.7
Accumulated other comprehensive income		0.5		0.5		0.4
Accumulated other comprehensive income, tax impact		0.1		0.1		$ 0.1
Defined benefit plan expense		0.1
Non-U.S.
Pension plans and other postretirement benefit plans
Defined benefit plan expense		0.6	0.8	1.3	1.6
Non-U.S. | Pension Plans
Pension plans and other postretirement benefit plans
Employer contributions		$ 0.6	$ 0.5	$ 1.5	$ 3.9

Other Balance Sheet Accounts -

Other Balance Sheet Accounts - Other Current Assets (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Other Current Assets:
Non-trade receivables	$ 19.8	$ 25
Prepaid expenses and other current assets	12.4	9.2
Income taxes receivable	11.8	10.4
Total other current assets	$ 44	$ 44.6

Other Balance Sheet Accounts _2

Other Balance Sheet Accounts - Other Current Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Other Current Liabilities:
Accrued customer volume rebates	$ 23.6	$ 35.3
Accrued compensation	13.4	16.4
Income taxes payable	12.1	17.2
Accrued interest	4.1	4
Pension liabilities	1.3	1.3
Restructuring liability	3.8	10.2
Other accrued liabilities	46.9	61.1
Total other current liabilities	105.2	145.5
Other current liabilities | Darex | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, deferred consideration	$ 0.5	$ 13.6

Commitments and Contingent Li_2

Commitments and Contingent Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Amended Credit Agreement | Standby Letter of Credit
Loss Contingencies [Line Items]
Gross financial assurances issued and outstanding	$ 5	$ 5

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details)	Mar. 15, 2019purchase_right$ / sharesshares	Jun. 30, 2019$ / sharesshares	Dec. 31, 2018$ / sharesshares
Equity [Abstract]
Common stock dividend, number of preferred share purchase rights for each share of common stock | purchase_right	1
Common stock, par value (in usd per share)		$ 0.01	$ 0.01
Preferred stock, par value (in usd per share)		$ 0.01	$ 0.01
Preferred share purchase right, exercise price (in dollars per share)	$ 150
Preferred share purchase right, ratio of number of shares per right	0.01
Preferred share purchase right, period after acquisition announcement after which rights become exercisable	10 days
Preferred share purchase right, minimum beneficial ownership percentage change for rights to become exercisable	15.00%
Preferred share purchase right, minimum beneficial ownership percentage for grandfathered treatment	15.00%
Preferred share purchase right, minimum ownership percentage at which existing rights become exercisable	0.001%
Preferred share purchase right, market value of common stock that Acquiring Person may acquire for exercise price	$ 300
Preferred share purchase right, ownership percentage threshold below which rights may be extinguished by board	50.00%
Preferred share purchase right, number of shares of common stock issued if rights extinguished by board (in shares)	1
Preferred share purchase right, purchase price of acquiring corporate shares	$ 150
Preferred share purchase right, market value of acquiring corporate shares	300
Class of Stock [Line Items]
Preferred stock, authorized (in shares) | shares		10,000,000	0
Preferred stock, par value (in usd per share)		$ 0.01	$ 0.01
Series A
Equity [Abstract]
Preferred stock, par value (in usd per share)	$ 0.01
Class of Stock [Line Items]
Preferred stock, authorized (in shares) | shares	10,000,000
Preferred stock, par value (in usd per share)	$ 0.01

Shareholders' Equity - Changes

Shareholders' Equity - Changes (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018		Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Schedule Of Equity [Line Items]
Beginning balance		$ 508	$ 504.5	$ 481.4		$ 492
Net income (loss)		2.6	(27.8)	24.2		(34.3)
Issuance of common stock in connection with stock plans	[1]			0		0
Share-based compensation		3.9	3.9	5.6		5.8
Exercise of stock options		$ 1.7	$ 1.6	$ 5		$ 5.1
Share repurchases (in shares)		(300)	(22,000)	(125,700)		(45,000)
Share repurchases		$ 0	$ (0.6)	$ (3.2)	[2]	$ (1.3)	[2]
Other comprehensive income (loss)		(3.9)	(33)	(0.7)		(18.7)
Ending balance		$ 512.3	448.6	512.3		448.6
Cash payments for tax withholding obligations			$ 0.6	$ 3.2		$ 1.3
Common Stock
Schedule Of Equity [Line Items]
Beginning balance (in shares)		72,900,000	72,200,000	72,400,000		71,900,000
Beginning balance		$ 0.7	$ 0.7	$ 0.7		$ 0.7
Issuance of common stock in connection with stock plans (in shares)			100,000	300,000	[1]	200,000	[1]
Exercise of stock options (in shares)		100,000	100,000	300,000		300,000
Ending balance (in shares)		73,000,000	72,400,000	73,000,000		72,400,000
Ending balance		$ 0.7	$ 0.7	$ 0.7		$ 0.7
Treasury Stock
Schedule Of Equity [Line Items]
Treasury Stock, Shares		300,000	200,000	300,000		200,000		300,000	200,000	200,000	100,000
Beginning balance		$ (8)	$ (4.1)	$ (4.8)		$ (3.4)
Share repurchases (in shares)	[2]			(100,000)		(100,000)
Share repurchases			(0.6)	$ (3.2)	[2]	$ (1.3)	[2]
Ending balance		(8)	(4.7)	(8)		(4.7)
Additional Paid-in Capital
Schedule Of Equity [Line Items]
Beginning balance		44.6	35.3	39.6		29.9
Share-based compensation		3.9	3.9	5.6		5.8
Exercise of stock options		1.7	1.6	5		5.1
Ending balance		50.2	40.8	50.2		40.8
Accumulated Earnings
Schedule Of Equity [Line Items]
Beginning balance		585.3	542.1	563.9		548.7
Net income (loss)		2.6	(27.9)	24		(34.5)
Ending balance		587.9	514.2	587.9		514.2
Accumulated Other Comprehensive Loss
Schedule Of Equity [Line Items]
Beginning balance		(116.8)	(71.4)	(120)		(85.7)
Other comprehensive income (loss)		(3.9)	(33)	(0.7)		(18.7)
Ending balance		(120.7)	(104.4)	(120.7)		(104.4)
Noncontrolling Interests
Schedule Of Equity [Line Items]
Beginning balance		2.2	1.9	2		1.8
Net income (loss)			0.1	0.2		0.2
Ending balance		$ 2.2	$ 2	$ 2.2		$ 2
[1]	The par value of shares issued is not included in the table due to rounding.
[2]	During the six months ended June 30, 2019 and 2018, GCP withheld and retained approximately 125,700 shares and 45,000 shares, respectively, of Company common stock in a non-cash transaction with a cost of $3.2 million and $1.3 million , respectively, in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the six months ended June 30, 2019 and 2018, cash payments for such tax withholding obligations were $3.2 million and $1.3 million , respectively.

Restructuring and Repositioni_3

Restructuring and Repositioning Expenses - Narrative (Details)	Aug. 01, 2018USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)segment	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Feb. 22, 2019USD ($)	Dec. 31, 2018USD ($)	Jun. 28, 2017USD ($)facility
Restructuring Cost and Reserve [Line Items]
Number of operating segments | segment						2
Restructuring liability		$ 3,800,000			$ 3,800,000	$ 3,800,000		$ 3,800,000		$ 10,200,000
Other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		300,000				400,000
2019 Plan
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		0			0	0		0
2019 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									$ 15,000,000
2019 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									20,000,000
2019 Plan, restructuring activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									4,000,000
2019 Plan, restructuring activities | Minimum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses									2,000,000
2019 Plan, restructuring activities | Minimum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses									1,000,000
2019 Plan, restructuring activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									7,000,000
2019 Plan, restructuring activities | Maximum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses									3,000,000
2019 Plan, restructuring activities | Maximum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses									3,000,000
2019 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		1,400,000				3,300,000
Cash payments		2,100,000				2,300,000
2019 Plan, repositioning activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses									1,000,000
2019 Plan, repositioning activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									11,000,000
2019 Plan, repositioning activities | Minimum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses									2,000,000
2019 Plan, repositioning activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses									13,000,000
2019 Plan, repositioning activities | Maximum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses									$ 3,000,000
2018 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		0	$ 400,000
Cash payments		2,300,000	2,200,000
Restructuring liability		3,500,000	5,800,000		3,500,000	3,500,000		3,500,000		7,700,000
2018 Plan | Other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		200,000	100,000
Cash payments		200,000	0
Restructuring liability		100,000	100,000		100,000	100,000		100,000		0
2018 Plan | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 32,000,000
2018 Plan | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	35,000,000
2018 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		20,900,000			20,900,000	20,900,000		20,900,000
2018 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		15,400,000			15,400,000	15,400,000		15,400,000
2018 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		5,500,000			5,500,000	5,500,000		5,500,000
2018 Plan, restructuring activities | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		11,800,000			11,800,000	11,800,000		11,800,000
2018 Plan, restructuring activities | Other associated costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		700,000			700,000	700,000		700,000
2018 Plan, restructuring activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		7,800,000			7,800,000	7,800,000		7,800,000
2018 Plan, restructuring activities | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	1,000,000
Costs incurred to date		600,000			600,000	600,000		600,000
2018 Plan, restructuring activities | Minimum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 21,000,000
Number of positions eliminated as a percent of total employees	8.00%
2018 Plan, restructuring activities | Minimum | SCC
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 16,000,000
2018 Plan, restructuring activities | Minimum | SBM
Restructuring Cost and Reserve [Line Items]
Estimated expenses	5,000,000
2018 Plan, restructuring activities | Minimum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	12,000,000
2018 Plan, restructuring activities | Minimum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	1,000,000
2018 Plan, restructuring activities | Minimum | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses	7,000,000
2018 Plan, restructuring activities | Maximum
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 24,000,000
Number of positions eliminated as a percent of total employees	10.00%
2018 Plan, restructuring activities | Maximum | SCC
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 18,000,000
2018 Plan, restructuring activities | Maximum | SBM
Restructuring Cost and Reserve [Line Items]
Estimated expenses	6,000,000
2018 Plan, restructuring activities | Maximum | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	13,000,000
2018 Plan, restructuring activities | Maximum | Other associated costs
Restructuring Cost and Reserve [Line Items]
Estimated expenses	2,000,000
2018 Plan, restructuring activities | Maximum | Asset impairments
Restructuring Cost and Reserve [Line Items]
Estimated expenses	8,000,000
2018 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses	$ 11,000,000
Costs incurred to date		10,400,000			10,400,000	10,400,000		10,400,000
Restructuring expenses		1,800,000				5,100,000
Cash payments		7,700,000			7,900,000
2017 Plan
Restructuring Cost and Reserve [Line Items]
Estimated expenses											$ 29,000,000
Number of plants to replace sold facilities | facility											2
2017 Plan | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		(100,000)	0
Cash payments		100,000	1,500,000
Restructuring liability		200,000	300,000		200,000	200,000		200,000		1,800,000
2017 Plan | Minimum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses											$ 10,000,000
2017 Plan | Maximum | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Estimated expenses											15,000,000
2017 Plan, restructuring activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses											19,000,000
Costs incurred to date		19,000,000			19,000,000	19,000,000		19,000,000
2017 Plan, restructuring activities | Discontinued operations
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		8,300,000			8,300,000	8,300,000		8,300,000
2017 Plan, restructuring activities | SCC
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		4,600,000			4,600,000	4,600,000		4,600,000
2017 Plan, restructuring activities | SBM
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		3,300,000			3,300,000	3,300,000		3,300,000
2017 Plan, restructuring activities | Corporate
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		2,800,000			2,800,000	2,800,000		2,800,000
2017 Plan, restructuring activities | Severance and other employee costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		17,300,000			17,300,000	17,300,000		17,300,000
2017 Plan, restructuring activities | Asset impairments
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		1,500,000			1,500,000	1,500,000		1,500,000
2017 Plan, restructuring activities | Facility exit costs
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		200,000			200,000	200,000		200,000
2017 Plan, repositioning activities
Restructuring Cost and Reserve [Line Items]
Estimated expenses											$ 10,000,000
Costs incurred to date		9,100,000			9,100,000	9,100,000		9,100,000
Restructuring expenses		200,000		$ 1,100,000		300,000	$ 2,000,000
Cash payments		2,600,000						16,700,000
2017 Plan, repositioning activities | Capital expenditures
Restructuring Cost and Reserve [Line Items]
Costs incurred to date		9,300,000			9,300,000	9,300,000		9,300,000
Cash payments		1,100,000
Total
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		400,000	400,000
Cash payments		3,100,000	4,000,000
Restructuring liability		3,800,000	$ 6,400,000		$ 3,800,000	$ 3,800,000		$ 3,800,000		$ 10,200,000
Strategic Alternatives Plan
Restructuring Cost and Reserve [Line Items]
Restructuring expenses		$ 2,500,000

Restructuring and Repositioni_4

Restructuring and Repositioning Expenses - Restructuring Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring and Related Activities [Abstract]
Severance and other employee costs	$ 0.2	$ (0.9)	$ 0.5	$ (0.7)
Asset impairments	3.8	0	4	0.4
Other associated costs	0.5	0	0.7	0
Total restructuring expenses and asset impairments	4.5	(0.9)	5.2	(0.3)
Less: restructuring expenses and asset impairments reflected in discontinued operations	0.1	(0.3)	0.2	0.8
Total restructuring expenses and asset impairments from continuing operations	$ 4.4	$ (0.6)	$ 5	$ (1.1)

Restructuring and Repositioni_5

Restructuring and Repositioning Expenses - Restructuring Costs by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	$ 4.4	$ (0.6)	$ 5	$ (1.1)
Restructuring expenses and asset impairments reflected in discontinued operations	0.1	(0.3)	0.2	0.8
Total restructuring expenses and asset impairments	4.5	(0.9)	5.2	(0.3)
Operating Segments | SCC
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	1.3	(0.6)	1.9	(1)
Operating Segments | SBM
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	3.2	0.1	3.2	(0.4)
Corporate
Restructuring Cost and Reserve [Line Items]
Total restructuring expenses and asset impairments from continuing operations	$ (0.1)	$ (0.1)	$ (0.1)	$ 0.3

Restructuring and Repositioni_6

Restructuring and Repositioning Expenses - Restructuring Liability (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018		$ 10.2		$ 10.2
Balance, March 31, 2019	$ 3.8			3.8
Asset impairments	3.8		$ 0	4	$ 0.4
Other plans
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	0.1	0.5		0.5
Expense	0.3	(0.1)
Payments	(0.4)	(0.2)
Impact of foreign currency and other	0	(0.1)
Balance, March 31, 2019	0	0.1		0
Total
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	6.4	10.2		10.2
Expense	0.4	0.4
Payments	(3.1)	(4)
Impact of foreign currency and other	0.1	(0.2)
Balance, March 31, 2019	3.8	6.4		3.8
Severance and other employee costs | 2018 Plan
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	5.8	7.7		7.7
Expense	0	0.4
Payments	(2.3)	(2.2)
Impact of foreign currency and other	0	(0.1)
Balance, March 31, 2019	3.5	5.8		3.5
Severance and other employee costs | 2017 Plan
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	0.3	1.8		1.8
Expense	(0.1)	0
Payments	(0.1)	(1.5)
Impact of foreign currency and other	0.1	0
Balance, March 31, 2019	0.2	0.3		0.2
Facility exit costs | 2018 Plan
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	0.1	0.2		0.2
Expense	0	0
Payments	(0.1)	(0.1)
Impact of foreign currency and other	0	0
Balance, March 31, 2019	0	0.1		0
Other Costs
Restructuring Reserve [Roll Forward]
Expense	0.3			0.4
Other Costs | 2018 Plan
Restructuring Reserve [Roll Forward]
Balance, December 31, 2018	0.1	0		0
Expense	0.2	0.1
Payments	(0.2)	0
Impact of foreign currency and other	0	0
Balance, March 31, 2019	0.1	$ 0.1		0.1
Asset impairments | SCC
Restructuring Reserve [Roll Forward]
Asset impairments	0.7			0.9
Asset impairments | SBM
Restructuring Reserve [Roll Forward]
Asset impairments	$ 3.1			$ 3.1

Other Comprehensive Loss - Comp

Other Comprehensive Loss - Components of OCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Pre-Tax Amount
Other comprehensive (loss) income, pre-tax amount	$ (3.9)	$ (33.2)	$ (0.7)	$ (18.9)
Tax Benefit/ (Expense)
Other comprehensive (loss) income, tax	0	0.2	0	0.2
After-Tax Amount
Total other comprehensive loss	(3.9)	(33)	(0.7)	(18.7)
Defined benefit pension and other postretirement plans
Pre-Tax Amount
Other comprehensive (loss) income, pre-tax amount				(0.8)
Tax Benefit/ (Expense)
Other comprehensive (loss) income, tax				0.2
After-Tax Amount
Total other comprehensive loss			0	(0.6)
Benefit plans, net
Pre-Tax Amount
Other comprehensive (loss) income, pre-tax amount		(0.8)
Tax Benefit/ (Expense)
Other comprehensive (loss) income, tax		0.2
After-Tax Amount
Total other comprehensive loss		(0.6)
Currency translation adjustments
Pre-Tax Amount
Other comprehensive (loss) income, pre-tax amount	(3.9)	(32.5)	(0.6)	(18.2)
Tax Benefit/ (Expense)
Other comprehensive (loss) income, tax	0	0	0	0
After-Tax Amount
Total other comprehensive loss	$ (3.9)	(32.5)	(0.6)	(18.2)
Loss (gain) from hedging activities
Pre-Tax Amount
Other comprehensive (loss) income, pre-tax amount		0.1	(0.1)	0.1
Tax Benefit/ (Expense)
Other comprehensive (loss) income, tax		0	0	0
After-Tax Amount
Total other comprehensive loss		$ 0.1	$ (0.1)	$ 0.1

Other Comprehensive Loss - Chan

Other Comprehensive Loss - Changes in AOCI, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	$ 508	$ 504.5	$ 481.4	$ 492
Current-period other comprehensive loss	(3.9)	(33)	(0.7)	(18.7)
Ending balance	512.3	448.6	512.3	448.6
Defined Benefit Pension and Other Postretirement Plans
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(2.2)	0.4
Current-period other comprehensive loss			0	(0.6)
Ending balance	(2.2)	(0.2)	(2.2)	(0.2)
Currency Translation Adjustments
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			(117.8)	(86)
Current-period other comprehensive loss			(0.6)	(18.2)
Ending balance	(118.4)	(104.2)	(118.4)	(104.2)
Hedging Activities
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance			0	(0.1)
Current-period other comprehensive loss			(0.1)	0.1
Ending balance	(0.1)	0	(0.1)	0
Total
Changes in accumulated other comprehensive income (loss), net of tax
Beginning balance	(116.8)	(71.4)	(120)	(85.7)
Current-period other comprehensive loss	(3.9)	(33)	(0.7)	(18.7)
Ending balance	$ (120.7)	$ (104.4)	$ (120.7)	$ (104.4)

Stock Incentive Plans - Narrati

Stock Incentive Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended				12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019		Jun. 30, 2018		Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock compensation (benefit) expense	$ 3.1	$ 3	$ 5		$ 4.9
Share repurchases (in shares)	300	22,000	125,700		45,000
Share repurchases	$ 0	$ 0.6	$ 3.2	[1]	$ 1.3	[1]
Cash payments for tax withholding obligations		$ 0.6	$ 3.2		1.3
Shares of common stock reserved and available for future grant (in shares)	7,600,000		7,600,000
Weighted average grant date fair value of options granted (in usd per share)	$ 9.58	$ 9.70
Fair value of awards vested			$ 6.1		4.8
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of all options exercised	$ 0.8	$ 1.2	2.5		$ 4.7
Unrecognized stock-based compensation expense for stock options	1.9		$ 1.9
Unrecognized stock-based compensation expense for stock options, period of recognition			1 year 1 month 6 days
Restricted Stock Units (RSUs) and Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense for stock options, period of recognition			1 year 7 months 6 days
Total unrecognized compensation expense related to the RSU and PBU awards	$ 7.6		$ 7.6
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Weighted average grant date fair value (in usd per share)	$ 29.52	$ 28.65	$ 26.91		$ 32.07
Amount settled in period (in shares)			237,000		116,000
Cash settlement of awards					$ 1.2
Awards granted (in shares)			133,000
Awards forfeited (in shares)			8,000
Awards outstanding (in shares)	251,000	300,000	251,000		300,000		363,000
Awards outstanding, weighted average grant date fair value (in usd per share)	$ 27.45		$ 27.45				$ 22.76
Restricted Stock Units (RSUs) | Vesting 1, Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
Restricted Stock Units (RSUs) | Vesting 1, Year 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
Restricted Stock Units (RSUs) | Vesting 1, Year 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			33.33%
Restricted Stock Units (RSUs) | Vesting 2, Year 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			0.00%
Restricted Stock Units (RSUs) | Vesting 2, Year 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			0.00%
Restricted Stock Units (RSUs) | Vesting 2, Year 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting percentage			100.00%
Sign-On Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			2 years
Award vesting percentage			100.00%
Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period			3 years
Performance Based Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected payout, percent of target			0.00%
Performance Based Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected payout, percent of target			200.00%
2016 Grant Date | Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount settled in period (in shares)	76,461
Performance period			3 years
Percentage of target award granted			68.70%
Awards forfeited (in shares)			34,840
Awards vested - weighted average granted date fair value (in usd per share)	$ 17.04
2016 Grant Date | Performance Based Units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected payout, percent of target			0.00%
2016 Grant Date | Performance Based Units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected payout, percent of target			200.00%
2017 and 2018 Grant Dates | Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period			3 years
2019 Grant Date | Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in usd per share)			$ 27.40
Awards granted (in shares)			167,519
Awards forfeited (in shares)			0
2018 Grant Date | Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in usd per share)							$ 34.14	$ 28.25
Awards granted (in shares)							149,974
Awards forfeited (in shares)			10,249
Awards outstanding (in shares)	133,548		133,548				143,797
Awards outstanding, weighted average grant date fair value (in usd per share)	$ 34.03		$ 34.03
2017 Grant Date | Performance Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)								166,821
Awards forfeited (in shares)			10,036
Awards outstanding (in shares)	128,879		128,879				138,915
[1]	During the six months ended June 30, 2019 and 2018, GCP withheld and retained approximately 125,700 shares and 45,000 shares, respectively, of Company common stock in a non-cash transaction with a cost of $3.2 million and $1.3 million , respectively, in connection with fulfilling statutory tax withholding requirements for employees under the provisions of the Company's equity compensation programs. During the six months ended June 30, 2019 and 2018, cash payments for such tax withholding obligations were $3.2 million and $1.3 million , respectively.

Stock Incentive Plans - Stock O

Stock Incentive Plans - Stock Options, Valuation Assumptions (Details) - Stock Option - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate, minimum	2.35%	2.68%
Risk-free interest rate, maximum	2.64%	2.90%
Volatility, minimum	28.02%	27.91%
Volatility, maximum	28.59%	30.65%
Dividend yield	0.00%	0.00%
Weighted average fair value per stock option (in usd per share)	$ 8.74	$ 11.02
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average life of options	5 years 6 months	5 years 6 months
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average life of options	6 years 6 months	6 years 6 months

Stock Incentive Plans - Stock_2

Stock Incentive Plans - Stock Option Activity (Details) - Stock Option - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Number Of Shares (in thousands)
Outstanding, beginning balance (in shares)	1,518
Options exercised (in shares)	(267)
Options forfeited/expired/canceled (in shares)	(27)
Options granted (in shares)	262
Outstanding, ending balance (in shares)	1,486	1,500	1,518
Exercisable, end of period (in shares)	1,009
Vested and expected to vest, end of period (in shares)	1,468
Weighted Average Exercise Price
Outstanding, beginning balance (in usd per share)	$ 21.18
Options exercised (in usd per share)	18.66
Options forfeited/expired/canceled (in usd per share)	27.66
Options granted (in usd per share)	26.65
Outstanding, ending balance (in usd per share)	22.47		$ 21.18
Exercisable, end of period (in usd per share)	19.90
Vested and expected to vest, end of period (in usd per share)	$ 22.42
Other Disclosures
Outstanding, weighted-average remaining contractual term	4 years 2 months 15 days		3 years 9 months
Exercisable, weighted-average remaining contractual term	3 years 1 month 17 days
Vested and expected to vest, weighted-average remaining contractual term	4 years 2 months 4 days
Outstanding, aggregated intrinsic value	$ 3,806		$ 7,145
Exercisable, aggregated intrinsic value	3,806
Vested and expected to vest, aggregated intrinsic value	$ 3,806

Stock Incentive Plans - Restric

Stock Incentive Plans - Restricted Stock Units Award Activity (Details) - Restricted Stock Units (RSUs) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Number Of Shares (in thousands)
Outstanding, beginning balance (in shares)			363
RSUs settled (in shares)			(237)
RSUs forfeited (in shares)			(8)
RSUs granted (in shares)			133
RSUs outstanding, ending balance (in shares)	251	300	251	300
RSUs expected to vest (in shares)	242		242
Weighted Average Grant Date Fair Value
Outstanding, beginning balance (in usd per share)			$ 22.76
RSUs settled (in usd per share)			19.90
RSUs forfeited (in used per share)			28.87
RSUs granted (in usd per share)	$ 29.52	$ 28.65	26.91	$ 32.07
RSUs outstanding, ending balance (in usd per share)	27.45		27.45
RSUs expected to vest (in usd per share)	$ 27.47		$ 27.47

Stock Incentive Plans - PBUs, V

Stock Incentive Plans - PBUs, Valuation Assumptions (Details) - Performance Based Units	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected Term (Remaining Performance Period)	2 years 10 months 9 days	2 years 10 months 9 days
Expected volatility	28.46%	28.56%
Risk-free interest rate	2.48%	2.38%
Expected dividends	0.00%	0.00%
Correlation coefficient	54.81%	38.98%
Average correlation coefficient of constituents	57.09%	39.96%

Earnings Per Share - Earnings P

Earnings Per Share - Earnings Per Share Reconciliation (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerators
Income (loss) from continuing operations attributable to GCP shareholders		$ 3.1	$ (29.2)	$ 17.7	$ (43)
(Loss) income from discontinued operations, net of income taxes		(0.5)	1.3	6.3	8.5
Net income (loss) attributable to GCP shareholders		$ 2.6	$ (27.9)	$ 24	$ (34.5)
Denominators
Weighted average common shares—basic calculation		72.6	72.1	72.5	72
Dilutive effect of employee stock awards (in shares)		0.4	0	0.4	0
Weighted average common shares—diluted calculation	[1]	73	72.1	72.9	72
Basic earnings (loss) per share
Income (loss) from continuing operations attributable to GCP shareholders (in usd per share)		$ 0.04	$ (0.40)	$ 0.24	$ (0.60)
(Loss) income from discontinued operations, net of income taxes (in usd per share)		(0.01)	0.02	0.09	0.12
Net income (loss) attributable to GCP shareholders (in usd per share)	[2]	0.04	(0.39)	0.33	(0.48)
Diluted earnings (loss) per share
Income (loss) from continuing operations attributable to GCP shareholders (in dollars per share)	[1]	0.04	(0.40)	0.24	(0.60)
(Loss) income from discontinued operations, net of income taxes (in dollars per share)	[1]	(0.01)	0.02	0.09	0.12
Net income (loss) attributable to GCP shareholders (in dollars per share)	[1],[2]	$ 0.04	$ (0.39)	$ 0.33	$ (0.48)
[1]	Dilutive effect is only applicable to the periods during which GCP generated net income from continuing operations.
[2]	Amounts may not sum due to rounding.

Earnings Per Share - Dilutive E

Earnings Per Share - Dilutive Effect of Options and RSUs (Details) - shares shares in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Earnings Per Share [Abstract]
Options	0.5	0.5
RSUs	0.2	0.2

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, treasury stock method (in shares)	600	600
Stock Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options outstanding (in shares)	1,486	1,486	1,518	1,500
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
RSUs outstanding (in shares)	251	251	363	300

Related Party Transactions an_2

Related Party Transactions and Transactions with Grace (Details) - W.R. Grace & Co. - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2018
Other assets
Related Party Transaction [Line Items]
Indemnified receivables, tax	$ 4	$ 3.9
Other current liabilities
Related Party Transaction [Line Items]
Indemnified payables, tax		$ 1.8	$ 1.9

Operating Segment and Geograp_3

Operating Segment and Geographic Information - Narrative (Details) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)segment	Dec. 31, 2018USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment	2
Operating lease right-of-use assets | $	$ 36.3	$ 0

Operating Segment and Geograp_4

Operating Segment and Geographic Information - Schedule of Operating Segment Data (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net Sales
Net sales	$ 262.2	$ 302.8	$ 488.3	$ 553
Segment Operating Income
Operating income	36.5	44.4	60.3	68.4
Specialty Construction Chemicals
Net Sales
Net sales	150.4	175	282.1	322
Segment Operating Income
Operating income	14.2	12.6	22.1	18.5
Specialty Building Materials
Net Sales
Net sales	111.8	127.8	206.2	231
Segment Operating Income
Operating income	$ 22.3	$ 31.8	$ 38.2	$ 49.9

Operating Segment and Geograp_5

Operating Segment and Geographic Information - Reconciliation of Segment Data to Financial Statements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Operating income	$ 36.5	$ 44.4	$ 60.3	$ 68.4
Corporate costs	(71.4)	(77.6)	(140.4)	(152.5)
Repositioning expenses	(5.8)	(1.2)	(11.2)	(2.1)
Restructuring expenses and asset impairments	(4.4)	0.6	(5)	1.1
Gain on termination and curtailment of pension and other postretirement plans			0	0.1
Net income attributable to noncontrolling interests	0	0.1	0.2	0.2
Income (loss) from continuing operations before income taxes	8.8	(34.4)	7.2	(34.6)
Loss on debt refinancing		59.8	0	59.8
Operating Segments
Segment Reporting Information [Line Items]
Operating income	36.5	44.4	60.3	68.4
Corporate
Segment Reporting Information [Line Items]
Corporate costs	(9.4)	(8.6)	(19.3)	(17.5)
Restructuring expenses and asset impairments	0.1	0.1	0.1	(0.3)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Certain pension costs	(2)	(1.9)	(3.9)	(3.8)
Other costs	(1.1)	0	(3.6)	0
Repositioning expenses	(5.8)	(1.2)	(11.2)	(2.1)
Restructuring expenses and asset impairments	(4.4)	0.6	(5)	1.1
Pension MTM adjustment and other related costs, net	0	(0.9)	0	(0.9)
Gain on termination and curtailment of pension and other postretirement plans	0	0.1	0	0.1
Third-party and other acquisition-related costs	0	(0.8)	(0.1)	(1.6)
Amortization of acquired inventory fair value adjustment	0	(0.2)	0	(0.2)
Legacy product, environmental and other claims	(0.1)	0	(0.1)	0
Net income attributable to noncontrolling interests	0	0.1	0.2	0.2
Interest expense, net	$ (4.9)	$ (66)	$ (10.1)	$ (78.3)

Operating Segment and Geograp_6

Operating Segment and Geographic Information - Geographic Area Data (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 262.2	$ 302.8	$ 488.3	$ 553
Operating lease right-of-use assets	36.3		36.3		$ 0
Specialty Construction Chemicals
Segment Reporting Information [Line Items]
Net sales	150.4	175	282.1	322
Specialty Building Materials
Segment Reporting Information [Line Items]
Net sales	111.8	127.8	206.2	231
Total North America
Segment Reporting Information [Line Items]
Net sales	135.8	149.3	249.3	272.3
Operating lease right-of-use assets	13.1		13.1
United States
Segment Reporting Information [Line Items]
Net sales	126.6	141.1	234.4	258
Operating lease right-of-use assets	12.9		12.9
Canada and Other
Segment Reporting Information [Line Items]
Net sales	9.2	8.2	14.9	14.3
Operating lease right-of-use assets	0.2		0.2
Europe Middle East Africa
Segment Reporting Information [Line Items]
Net sales	52.3	69.2	98.7	127.5
Operating lease right-of-use assets	12.9		12.9
Asia Pacific
Segment Reporting Information [Line Items]
Net sales	58.9	65.7	109.6	117.7
Operating lease right-of-use assets	9.1		9.1
Latin America
Segment Reporting Information [Line Items]
Net sales	15.2	$ 18.6	30.7	$ 35.5
Operating lease right-of-use assets	1.2		1.2
Operating Segments | Specialty Construction Chemicals
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	18.9		18.9
Operating Segments | Specialty Building Materials
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	14		14
Corporate
Segment Reporting Information [Line Items]
Operating lease right-of-use assets	$ 3.4		$ 3.4

Acquisitions (Details)

Acquisitions (Details) - USD ($)	May 04, 2018	Dec. 31, 2018	Jun. 30, 2019
Clydebridge Holdings
Business Acquisition [Line Items]
Percentage of stock acquired	100.00%
Consideration transferred	$ 29,700,000
Cash acquired	10,000,000
Payments to acquire businesses	29,800,000
Working capital adjustments	$ 100,000
Purchase price adjustment, reduction in consideration paid		$ 200,000
Purchase price adjustment, reduction in inventories		$ 200,000
Escrow deposit disbursements			$ 0
RIW Limited | Clydebridge Holdings
Business Acquisition [Line Items]
Percentage of stock acquired	100.00%

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) - Disposed of by Sale - Darex - USD ($) $ in Millions	Jul. 03, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration received/receivable for disposal	$ 1,060
After-tax gain on sale			$ 10.3	$ 7.2	$ 10.3
Reduction in deferred consideration		$ 13.1
Provision for income taxes of discontinued operations				2.4	$ 8.2
Term of transition services agreement	36 months
Indemnification payable		0.9		0.9		$ 0.9
Other current liabilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, deferred consideration		$ 0.5		$ 0.5		$ 13.6

Discontinued Operations - Recon

Discontinued Operations - Reconciliation of Gain on Disposal (Details) - Darex - Disposed of by Sale - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net proceeds included in gain		$ 12.7	$ 25
Net assets derecognized		(3.1)	(6.5)
Gain recognized before income taxes		9.6	18.5
Tax effect of gain recognized		(2.4)	(8.2)
Gain recognized after income taxes	$ 10.3	$ 7.2	$ 10.3

Discontinued Operations - Incom

Discontinued Operations - Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations, net of income taxes	$ (0.5)	$ 1.3	$ 6.3	$ 8.5
Darex | Discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	0	5.9	0	11.6
Cost of goods sold	0	5.6	0	12.7
Gross profit	0	0.3	0	(1.1)
Selling, general and administrative expenses	0.6	1.5	0.9	3.3
Restructuring expenses and asset impairments	0.1	(0.3)	0.2	0.8
Gain on sale of business	0	0	(9.6)	(18.5)
Other income, net	(0.1)	(2.9)	0	(3.1)
(Loss) income from discontinued operations before income taxes	(0.6)	2	8.5	16.4
Benefit from (provision for) income taxes	0.1	(0.7)	(2.2)	(7.9)
(Loss) income from discontinued operations, net of income taxes	$ (0.5)	$ 1.3	$ 6.3	$ 8.5

Discontinued Operations - Carry

Discontinued Operations - Carrying Amounts of Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets held for sale	$ 0	$ 3.4
Non-current assets held for sale	0.5	0.7
Non-current liabilities held for sale	0	0.4
Darex | Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Trade accounts receivable	0	2.2
Inventories, net	0	1.2
Current assets held for sale	0	3.4
Properties and equipment, net	0	0.2
Other assets	0.5	0.5
Non-current assets held for sale	0.5	0.7
Underfunded and unfunded defined benefit pension plans	0	0.4
Non-current liabilities held for sale	$ 0	$ 0.4

Subsequent Event (Details)

Subsequent Event (Details) - Subsequent Event $ in Millions	Jul. 31, 2019USD ($)
2019 Phase 2 Plan | Severance and other employee costs
Subsequent Event [Line Items]
Percentage of total restructuring costs	90.00%
2019 Phase 2 Plan | Other associated costs, including asset impairments
Subsequent Event [Line Items]
Percentage of total restructuring costs	10.00%
2019 Phase 2 Plan | Minimum
Subsequent Event [Line Items]
Estimated expenses	$ 30
2019 Phase 2 Plan | Maximum
Subsequent Event [Line Items]
Estimated expenses	35
2019 Phase 2 Plan, restructuring activities | Minimum
Subsequent Event [Line Items]
Estimated expenses	$ 23
Number of positions eliminated as a percent of total employees	8.00%
2019 Phase 2 Plan, restructuring activities | Maximum
Subsequent Event [Line Items]
Estimated expenses	$ 27
Number of positions eliminated as a percent of total employees	10.00%
2019 Phase 2 Plan, repositioning activities | Capital expenditures
Subsequent Event [Line Items]
Estimated expenses	$ 2
2019 Phase 2 Plan, repositioning activities | Minimum
Subsequent Event [Line Items]
Estimated expenses	7
2019 Phase 2 Plan, repositioning activities | Maximum
Subsequent Event [Line Items]
Estimated expenses	$ 8