W.R. Grace & Co. (GRA) 10-Q 8 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document and Entity Information	'	'
Entity Registrant Name	'W R GRACE & CO	'
Entity Central Index Key	'0001045309	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-13	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	76,896,708
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net sales	$771.30	$776.60	$2,284	$2,357.70
Cost of goods sold	486.6	491.8	1,432.20	1,491.70
Gross profit	284.7	284.8	851.8	866
Selling, general and administrative expenses	125.2	130.8	391.7	401.2
Restructuring expenses and related asset impairments	3.6	1.1	8.7	6.4
Research and development expenses	15	15.4	48.5	47.9
Defined benefit pension expense	18.2	17.6	54.9	53.2
Interest expense and related financing costs	10.7	11.5	32.1	34.1
Provision for environmental remediation	1.7	0.6	4	1.8
Chapter 11 expenses, net of interest income	2.9	4.4	11	12.6
Libby medical program settlement	0	0.1	0	19.6
Equity in earnings of unconsolidated affiliate	-2.8	-4.9	-17.1	-13.8
Other (income) expense, net	0.7	-3.2	5.1	-6
Total costs and expenses	175.2	173.4	538.9	557
Income before income taxes	109.5	111.4	312.9	309
Provision for income taxes	-39.8	-35.4	-106.7	-102
Net income	69.7	76	206.2	207
Less: Net income attributable to noncontrolling interests	-0.3	-0.5	-1.1	-1.3
Net income attributable to W. R. Grace & Co. shareholders	$69.40	$75.50	$205.10	$205.70
Basic earnings per share:	'	'	'	'
Net income attributable to W. R. Grace & Co. shareholders (in dollars per share)	$0.90	$1.01	$2.69	$2.75
Weighted average number of basic shares	76.7	75	76.2	74.7
Diluted earnings per share:	'	'	'	'
Net income attributable to W. R. Grace & Co. shareholders (in dollars per share)	$0.89	$0.99	$2.64	$2.70
Weighted average number of diluted shares	77.9	76.4	77.6	76.2

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$69.70	$76	$206.20	$207
Other comprehensive income (loss):	'	'	'	'
Defined benefit pension and other postretirement plans, net of income taxes	28.8	-13	98.3	-40.3
Currency translation adjustments	5	14.5	-18.3	5.1
Gain (loss) from hedging activities, net of income taxes	0	1.5	-0.4	3
Total other comprehensive income (loss) attributable to noncontrolling interests	-0.7	-0.3	-0.9	0
Total other comprehensive income	33.1	2.7	78.7	-32.2
Comprehensive income	102.8	78.7	284.9	174.8
Less: comprehensive income attributable to noncontrolling interests	0.4	-0.2	-0.2	-1.3
Comprehensive income attributable to W. R. Grace & Co. shareholders	$103.20	$78.50	$284.70	$173.50

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES	'	'
Net income	$206.20	$207
Reconciliation to net cash provided by operating activities:	'	'
Depreciation and amortization	91.8	88.9
Equity in earnings of unconsolidated affiliate	-17.1	-13.8
Dividends received from unconsolidated affiliate	2.8	6.3
Chapter 11 expenses, net of interest income	11	12.6
Chapter 11 expenses paid	-11.2	-9.9
Libby medical program settlement	0	19.6
Provision for income taxes	106.7	102
Income taxes paid, net of refunds	-65.6	-41.6
Interest accrued on pre-petition liabilities subject to compromise	28.1	30
Restructuring expenses and related asset impairments	8.7	6.4
Payments for restructuring expenses	-3.8	-7.2
Defined benefit pension expense	54.9	53.2
Payments under defined benefit pension arrangements	-63.6	-122.5
Provision for environmental remediation	4	1.8
Expenditures for environmental remediation	-11.2	-8.1
Changes in assets and liabilities, excluding effect of currency translation:	'	'
Trade accounts receivable	5.2	-3.7
Inventories	-37.7	20.6
Accounts payable	6.8	3.6
All other items, net	-7.1	-10.2
Net cash provided by (used for) operating activities	342.6	292.4
INVESTING ACTIVITIES	'	'
Capital expenditures	-117.9	-103.6
Payments to Acquire Businesses, Net of Cash Acquired	-15.8	-40.5
Short-term Investments	-500	0
Transfer to restricted cash and cash equivalents	12.4	-24.1
Proceeds from Divestiture of Businesses	1.8	0
Other investing activities	4.2	0.5
Net cash used for investing activities	-615.3	-167.7
FINANCING ACTIVITIES	'	'
Net borrowings (repayments) under credit arrangements	-3	24.6
Proceeds from exercise of stock options	30.9	25.7
Other financing activities	6.1	5.1
Net cash (used for) provided by financing activities	0.3	78.4
Effect of currency exchange rate changes on cash and cash equivalents	-9.8	-0.2
Decrease in cash and cash equivalents	-282.2	202.9
Cash and cash equivalents, beginning of period	1,336.90	1,048.30
Cash and cash equivalents, end of period	$1,054.70	$1,251.20

Consolidated_Balance_Sheets_un

Consolidated Balance Sheets (unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current Assets	'	'
Cash and cash equivalents	$1,054.70	$1,336.90
Short-term Investments	500	0
Restricted cash and cash equivalents	185.2	197.6
Trade accounts receivable, less allowance of $5.4 (2012—$5.2)	467.8	474.8
Accounts receivable—unconsolidated affiliate	16.1	15.6
Inventories	314.8	278.6
Deferred income taxes	10.6	58.3
Other current assets	140.4	78.4
Total Current Assets	2,689.60	2,440.20
Properties and equipment, net of accumulated depreciation and amortization of $1,830.2 (2012—$1,785.1)	787.8	770.5
Goodwill	204	196.7
Patents, licenses and other intangible assets, net	76.9	82.7
Deferred income taxes	814.6	956.3
Asbestos-related insurance	500	500
Overfunded defined benefit pension plans	30.2	33.8
Investment in unconsolidated affiliate	90.8	85.5
Other assets	36.1	24.5
Total Assets	5,230	5,090.20
Current Liabilities	'	'
Debt payable within one year	86.2	83.4
Debt payable—unconsolidated affiliate	4.5	3.6
Accounts payable	249.5	249.4
Accounts payable—unconsolidated affiliate	10.8	2.6
Other current liabilities	289.3	307.3
Total Current Liabilities	640.3	646.3
Debt payable after one year	7.4	13.4
Debt payable—unconsolidated affiliate	24.1	22.4
Deferred income taxes	23.9	27.1
Underfunded and unfunded defined benefit pension plans	250.8	400.6
Other liabilities	45.2	45
Total Liabilities Not Subject to Compromise	991.7	1,154.80
Liabilities Subject to Compromise-Note 2	'	'
Debt plus accrued interest	997.5	973.3
Income tax contingencies	85.4	87.6
Asbestos-related contingencies	2,065	2,065
Environmental contingencies	134	140.5
Postretirement benefits	174.8	188.1
Other liabilities and accrued interest	169.7	162.6
Total Liabilities Subject to Compromise	3,626.40	3,617.10
Total Liabilities	4,618.10	4,771.90
Commitments and Contingencies—Note 10	'	'
Equity	'	'
Common stock issued, par value $0.01; 300,000,000 shares authorized; outstanding: 76,849,629 (2012—75,565,409)	0.8	0.8
Paid-in capital	530.1	536.5
Retained earnings	600.3	395.2
Treasury stock, at cost: shares: 140,571 (2012—1,414,351)	-1.7	-16.8
Accumulated other comprehensive loss	-527.7	-607.3
Total W. R. Grace & Co. Shareholders' Equity	601.8	308.4
Noncontrolling interests	10.1	9.9
Total Equity	611.9	318.3
Total Liabilities and Equity	$5,230	$5,090.20

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Trade accounts receivable, allowance	$5.40	$5.20
Properties and equipment, accumulated depreciation and amortization (in dollars)	$1,830.20	$1,785.10
Common stock issued, par value (in dollars per share)	$0.01	$0.01
Common stock issued, shares authorized	300,000,000	300,000,000
Common stock issued, shares outstanding	76,849,629	75,565,409
Treasury stock, shares	140,571	1,414,351

Consolidated_Statements_of_Equ

Consolidated Statements of Equity (unaudited) (USD $)	Total	Common Stock and Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Noncontrolling Interests
In Millions, unless otherwise specified
Balance at Dec. 31, 2011	$167.50	$473.60	$301.10	($36.80)	($578.50)	$8.10
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'
Net income	207	0	205.7	0	0	1.3
Stock plan activity	11.2	11.2	0	0	0	0
Stock Issued During Period, Value, Stock Options Exercised	25.7	9.5	0	16.2	0	0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	23	23	0	0	0	0
Other comprehensive income	-32.2	0	0	0	-32.2	0
Balance at Sep. 30, 2012	402.2	517.3	506.8	-20.6	-610.7	9.4
Balance at Dec. 31, 2012	318.3	537.3	395.2	-16.8	-607.3	9.9
Increase (Decrease) in Stockholders' Equity	'	'	'	'	'	'
Net income	206.2	0	205.1	0	0	1.1
Stock plan activity	10.7	10.7	0	0	0	0
Stock Issued During Period, Value, Stock Options Exercised	30.9	15.8	0	15.1	0	0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	-33.7	-33.7	0	0	0	0
Shares issued	0.8	0.8	0	0	0	0
Other comprehensive income	78.7	0	0	0	79.6	-0.9
Balance at Sep. 30, 2013	$611.90	$530.90	$600.30	($1.70)	($527.70)	$10.10

Basis_of_Presentation_and_Summ

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies	9 Months Ended
	Sep. 30, 2013
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
	W. R. Grace & Co., through its subsidiaries, is engaged in specialty chemicals and specialty materials businesses on a global basis through three operating segments: Grace Catalysts Technologies, which includes catalysts and related products used in refining, petrochemical and other chemical manufacturing applications; Grace Materials Technologies, which includes packaging technologies and engineered materials used in consumer, industrial, coatings, and pharmaceutical applications; and Grace Construction Products, which includes specialty construction chemicals and specialty building materials used in commercial, infrastructure and residential construction.
	W. R. Grace & Co. conducts substantially all of its business through a direct, wholly owned subsidiary, W. R. Grace & Co.-Conn. ("Grace-Conn."). Grace-Conn. owns substantially all of the assets, properties and rights of W. R. Grace & Co. on a consolidated basis, either directly or through subsidiaries.
	As used in these notes, the term "Company" refers to W. R. Grace & Co. The term "Grace" refers to the Company and/or one or more of its subsidiaries and, in certain cases, their respective predecessors.
	Voluntary Bankruptcy Filing    During 2000 and the first quarter of 2001, Grace experienced several adverse developments in its asbestos-related litigation, including: a significant increase in personal injury claims, higher than expected costs to resolve personal injury and certain property damage claims, and class action lawsuits alleging damages from ZONOLITE® Attic Insulation ("ZAI"), a former Grace attic insulation product.
	After a thorough review of these developments, Grace's Board of Directors concluded that a federal court-supervised bankruptcy process provided the best forum available to achieve fairness in resolving these claims and on April 2, 2001 (the "Filing Date"), Grace and 61 of its United States subsidiaries and affiliates, (collectively, the "Debtors"), filed voluntary petitions for reorganization (the "Filing") under Chapter 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the District of Delaware (the "Bankruptcy Court"). The cases were consolidated and are being jointly administered under case number 01-01139 (the "Chapter 11 Cases"). Grace's non-U.S. subsidiaries and certain of its U.S. subsidiaries were not included in the Filing.
	Under Chapter 11, the Debtors have continued to operate their businesses as debtors-in-possession under court protection from creditors and claimants, while using the Chapter 11 process to develop and implement a plan for addressing the asbestos-related claims. Since the Filing, all motions necessary to conduct normal business activities have been approved by the Bankruptcy Court. (See Note 2 for Chapter 11 Information.)
	Basis of Presentation    The interim Consolidated Financial Statements presented herein are unaudited and should be read in conjunction with the Consolidated Financial Statements presented in the Company's 2012 Annual Report on Form 10-K. Such interim Consolidated 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 as discussed below. All significant intercompany accounts and transactions have been eliminated.
	The results of operations for the nine-month interim period ended September 30, 2013, are not necessarily indicative of the results of operations for the year ending December 31, 2013.
	Reclassifications and Revisions    Certain amounts in prior years' Consolidated Financial Statements have been reclassified to conform to the current year presentation. Such reclassifications have not materially affected previously reported amounts in the Consolidated Financial Statements.
	Certain prior period amounts have been revised to correct the previous classification. Cash payments associated with capital expenditures of $9.6 million for the period ended September 30, 2012, previously classified as operating activities in the Statements of Cash Flows have been revised to investing activities.
	Grace concluded that these revisions were not material to the prior-year Consolidated Financial Statements.
	Use of Estimates    The preparation of financial statements in conformity with U.S. generally accepted accounting principles (U.S. 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 Consolidated Financial Statements, and the reported amounts of revenues and expenses for the periods presented. Actual amounts could differ from those estimates, and the differences could be material. Changes in estimates are recorded in the period identified. Grace's accounting measurements that are most affected by management's estimates of future events are:
	•	Contingent liabilities, which depend on an assessment of the probability of loss and an estimate of ultimate resolution cost, such as asbestos-related matters and litigation (see Notes 2 and 3), income taxes (see Note 7), and environmental remediation (see Note 10);
	•	Pension and postretirement liabilities that depend on assumptions regarding participant life spans, future inflation, discount rates and total returns on invested funds (see Note 8);
	•	Realization values of net deferred tax assets and insurance receivables, which depend on projections of future income and cash flows and assessments of insurance coverage and insurer solvency; and
	•	Recoverability of goodwill, which depends on assumptions used to value reporting units, such as observable market inputs, projections of future cash flows and weighted average cost of capital. The Grace Construction Products (GCP) Europe reporting unit continues to operate in a challenging environment. While the fair value of this reporting unit exceeded the carrying value at its last testing date and management does not believe that impairment is probable, the business must continue to improve its performance in future periods, consistent with expectations, to sustain the goodwill carrying value.
	The accuracy of management's estimates may be materially affected by the uncertainties arising under Grace's Chapter 11 proceeding.
	Currency Translation    On February 8, 2013, the Venezuelan government announced that, effective February 13, 2013, the official exchange rate of the bolivar to U.S. dollar would devalue from 4.3 to 6.3. As a result of this currency devaluation, Grace incurred a charge to net income of $8.5 million in the 2013 first quarter. Of this amount, $1.6 million is included in segment operating income.
	Short-Term Investments  On April 1, 2013, Grace invested $500.0 million in a series of short-term cash investments with a major financial institution. The investments will be liquidated prior to Grace's emergence from bankruptcy.
	Effect of New Accounting Standards    In June 2011, the FASB issued ASU 2011-05 "Presentation of Comprehensive Income". This update is intended to improve the comparability, consistency, and transparency of financial reporting and to increase the prominence of items reported in other comprehensive income. The new disclosure requirements are effective for fiscal years beginning after December 15, 2011, and for interim periods within those fiscal years, with early adoption permitted. In December 2011, the FASB issued ASU 2011-12 "Deferral of the Effective Date for Amendments to the Presentation of Reclassifications of Items Out of Accumulated Other Comprehensive Income in Accounting Standards Update No. 2011-05". This update defers certain paragraphs of ASU 2011-05 pertaining to reclassification adjustments out of accumulated other comprehensive income. This deferral is effective for fiscal years beginning after December 15, 2011, and for interim periods within those fiscal years, with early adoption permitted. Grace continues to report its Consolidated Statement of Other Comprehensive Income as a separate financial statement, immediately following the Consolidated Statement of Operations to comply with the updates that have not been deferred. In February 2013, the FASB issued ASU 2013-02 "Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income", which further clarifies these disclosure requirements. This update is effective for fiscal years beginning after December 15, 2012, and for interim periods within those fiscal years, with early adoption permitted. Grace adopted this update in the 2013 first quarter and it did not have a material effect on the Consolidated Financial Statements.
	In December 2011, the FASB issued ASU 2011-11 "Disclosures about Offsetting Assets and Liabilities". This update is intended to improve the comparability of statements of financial position prepared in accordance with U.S. GAAP and IFRS, requiring both gross and net information about offsetting assets and liabilities. The new requirements are effective for fiscal years beginning on or after January 1, 2013, and for interim periods within those fiscal years. In January 2013, the FASB issued ASU 2013-01 "Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities", which clarifies these disclosure requirements. These standards are effective for fiscal years beginning on or after January 1, 2013, and for interim periods within those fiscal years. Grace adopted these standards for the 2013 first quarter and they did not have a material effect on the Consolidated Financial Statements.
	In July 2013, the FASB issued ASU 2013-11 "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists". This update is intended to improve the consistency surrounding the presentation of an unrecognized tax benefit when a net operating loss carryforward exists, requiring the unrecognized tax benefit to be presented as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward. The new requirements are effective for fiscal years beginning after December 15, 2013, and for interim periods within those fiscal years. Grace will adopt these standards for the 2014 first quarter.

Chapter_11_Information

Chapter 11 Information	9 Months Ended
	Sep. 30, 2013
Reorganizations [Abstract]	'
Chapter 11 Information	'
	Chapter 11 Information
	Official Parties to Grace's Chapter 11 Cases    The Bankruptcy Court has appointed four official committees. The Official Committee of Asbestos Personal Injury Claimants (the "PI Committee") and the Official Committee of Asbestos Property Damage Claimants (the "PD Committee") respectively represent two different asbestos claimant constituencies. The other two committees are the Official Committee of Unsecured Creditors (the "Creditors' Committee"), which represents general unsecured creditors, and the Official Committee of Equity Security Holders (the "Equity Committee"), which represents equity security holders. These committees, along with a legal representative of future asbestos personal injury claimants (the "PI FCR") and a legal representative of future asbestos property damage claimants (the "PD FCR"), have the right to be heard on all matters that come before the Bankruptcy Court and have important roles in the Chapter 11 Cases. The Debtors are required to bear certain costs and expenses of the committees and the representatives of future asbestos claimants, including those of their counsel and financial advisors.
	As discussed below, the Debtors, the Equity Committee, the PI Committee and the PI FCR have filed a joint plan of reorganization, subsequently amended, with the Bankruptcy Court that is designed to address all pending and future asbestos-related claims and all other pre-petition claims as outlined therein (as amended to date, the "Joint Plan"). The Creditors' Committee, the PD Committee and the PD FCR are not co-proponents of the Joint Plan. On January 31, 2011, the Bankruptcy Court issued an order confirming the Joint Plan. On January 31, 2012, the United States District Court for the District of Delaware (the "District Court") issued an order affirming the Bankruptcy Court's confirmation order, denying all appeals from the confirmation order and confirming the Joint Plan in its entirety. Appeals have been filed with the Court of Appeals for the Third Circuit (the "Third Circuit") challenging the District Court order confirming the Joint Plan. As of September 30, 2013, the Third Circuit has issued orders denying all but one of those appeals. There could be further appeals of one or more of those orders. Grace is awaiting a decision with respect to the remaining appeal. The resolution of any such appeals could have a material effect on the terms and timing of Grace's emergence from Chapter 11. In order for the Joint Plan to become effective, all conditions to the effective date set forth in the Joint Plan must be satisfied or waived.
	Plans of Reorganization    Prior to 2008, competing plans of reorganization were filed by Grace and jointly by the PI Committee and the PI FCR. Grace filed its first proposed plan with the Bankruptcy Court in November 2004 and amended it in January 2005 (the "Prior Plan"). However, in April 2008, the Debtors reached an agreement in principle with the PI Committee, the PI FCR, and the Equity Committee designed to resolve all present and future asbestos-related personal injury claims (the "PI Settlement"). A trial for estimating liability for such claims began in January 2008 but was suspended in April 2008 as a result of the PI Settlement.
	As contemplated by the PI Settlement, in September 2008, the Debtors, supported by the Equity Committee, the PI Committee and the PI FCR, as co-proponents, filed the Joint Plan to reflect the terms of the PI Settlement. The Joint Plan supersedes the Prior Plan and all other previously filed plans.
	In November 2008, the Debtors reached an agreement in principle (the "ZAI PD Term Sheet") with the Putative Class Counsel to the U.S. ZAI claimants, the PD FCR, and the Equity Committee designed to resolve all present and future U.S. ZAI property damage claims and demands.
	In January 2011, the Company, Grace Canada, Inc. and legal representatives of Canadian ZAI property damage claimants became parties to an agreement that would settle all Canadian ZAI property damage claims and demands (the "Canadian ZAI Settlement"). Under that agreement, all Canadian ZAI property damage claims and demands would be paid through a separate Canadian ZAI property damage claims fund of CDN$8.6 million. The Canadian ZAI Settlement is subject to the effectiveness of the Joint Plan.
	The Joint Plan is designed to address all pending and future asbestos-related claims and all other pre-petition claims as outlined therein. Under the Joint Plan, two asbestos trusts would be established under Section 524(g) of the Bankruptcy Code. All asbestos-related personal injury claims would be channeled for resolution to one asbestos trust (the "PI Trust") and all asbestos-related property damage claims, including U.S. and Canadian ZAI property damage claims, would be channeled to a separate asbestos trust (the "PD Trust"). Amendments and technical modifications to the Joint Plan and several associated documents were filed by the Debtors and co-proponents on nine occasions from December 2008 through December 2010 to, among other things, reflect the agreements described above.
	The Joint Plan assumes that Cryovac, Inc. ("Cryovac"), a wholly owned subsidiary of Sealed Air Corporation ("Sealed Air"), will fund the PI Trust and the PD Trust with an aggregate of: (i) $512.5 million in cash (plus interest at 5.5% compounded annually from December 21, 2002); and (ii) 18 million shares (reflecting a two-for-one stock split) of common stock of Sealed Air, pursuant to the terms of a settlement agreement resolving asbestos-related, successor liability and fraudulent transfer claims against Sealed Air and Cryovac (the "Sealed Air Settlement"). The value of the Sealed Air Settlement changes daily with the accrual of interest and the trading value of Sealed Air common stock. The Joint Plan also assumes that Fresenius AG ("Fresenius") will fund the PI Trust and the PD Trust with an aggregate of $115.0 million pursuant to the terms of a settlement agreement resolving asbestos-related, successor liability and fraudulent transfer claims against Fresenius (the "Fresenius Settlement"). The Sealed Air Settlement and the Fresenius Settlement have been approved by the Bankruptcy Court but remain subject to the fulfillment of specified conditions.
	Any plan of reorganization, including the Joint Plan and any plan of reorganization that may be filed in the future by a party-in-interest, will become effective only after a vote of eligible creditors and with the approval of the Bankruptcy Court and the District Court.
	All classes of creditors entitled to vote accepted the Joint Plan in May 2009. The class of general unsecured creditors, who voted on a provisional basis pending a determination as to whether the class is impaired and therefore entitled to a vote, voted to reject the Joint Plan. In January 2011, the Bankruptcy Court issued an order confirming the Joint Plan and overruling all objections. In January 2012, the District Court issued an order affirming the Bankruptcy Court's confirmation order, denying all appeals from the confirmation order and confirming the Joint Plan in its entirety. On June 11, 2012, the District Court reaffirmed the confirmation order and the denial of all appeals after motions for reconsideration.
	Eight parties filed notices of appeal on or before the July 11, 2012, deadline for appeals, of which five were briefed, argued and submitted to the Third Circuit. The appeals generally relate to demands for interest at rates higher than provided for in the Joint Plan, the validity of the asbestos channeling injunctions, and the classification and treatment of claims under the Joint Plan. In rulings issued in July and September 2103, the Third Circuit Court denied four of the five appeals. There could be further appeals of one or more of those rulings. Grace is awaiting a decision with respect to the remaining appeal.
	On June 5, 2012, the Bankruptcy Court approved agreements among Grace, co-proponents of the Joint Plan, BNSF, and the representatives of Libby, Montana, asbestos personal injury claimants to settle certain objections to the Joint Plan. Those agreements became effective on September 21, 2012, resulting in the withdrawal of the appeals to the Joint Plan by the Libby claimants, BNSF and an insurance company. In addition, in accordance with the agreements, Grace transferred responsibility for the former Grace-operated Libby Medical Program to a locally administered trust and funded the trust with a one-time payment of $19.6 million. Payments to Libby claimants under the Joint Plan are not affected by the Grace-Libby agreement.
	The timing of the effectiveness of the Joint Plan and Grace's subsequent emergence will depend on final resolution of all appeals by claimants and the satisfaction or waiver by Grace, Grace's co-proponents under the Joint Plan, and Sealed Air and Fresenius of the remaining conditions to effectiveness set forth in the Joint Plan, including the availability of any required exit financing and the final resolution of all appeals.
	If any of the appeals are resolved adversely to Grace and the other Joint Plan proponents, the Joint Plan may be amended to address the deficiencies identified by the Third Circuit or the Joint Plan may be terminated and a new plan proposed. If the Joint Plan cannot be amended to address all deficiencies identified by the Third Circuit in a manner satisfactory to Grace and the other Joint Plan proponents and Grace cannot reach an agreement with its asbestos creditors on the terms of a new plan of reorganization, Grace would expect to resume the estimation trial, which was suspended in April 2008 due to the PI Settlement, to determine the amount of the asbestos-related liabilities. Whether the Joint Plan is amended or a different plan of reorganization is ultimately confirmed, the value of the interests of holders of Company common stock could be materially different than under the current Joint Plan and the Company common stock could be substantially diluted or canceled.
	Joint Plan of Reorganization    Under the terms of the Joint Plan, claims under the Chapter 11 Cases would be satisfied as follows:
	Asbestos-Related Personal Injury Claims
	All pending and future asbestos-related personal injury claims and demands ("PI Claims") would be channeled to the PI Trust for resolution. The PI Trust would use specified trust distribution procedures to satisfy allowed PI Claims.
	The PI Trust would be funded with:
	•	$250 million in cash plus interest thereon from January 1, 2009, to the effective date of the Joint Plan to be paid by Grace;
	•	Cash in the amount of the PD Initial Payment (as described below) and the ZAI Initial Payment (as described below) to be paid by Grace;
	•	A warrant to acquire 10 million shares of Company common stock at an exercise price of $17.00 per share, expiring one year from the effective date of the Joint Plan. This obligation will be settled in cash with the PI Trust as discussed below;
	•	Rights to all proceeds under all of the Debtors' insurance policies that are available for payment of PI Claims;
	•	Cash in the amount of $512.5 million plus interest thereon from December 21, 2002, to the effective date of the Joint Plan at a rate of 5.5% per annum to be paid by Cryovac reduced by the amount of Cryovac's contribution to the PD Initial Payment and the ZAI Initial Payment (as described below) and 18 million shares of Sealed Air common stock to be paid by Cryovac pursuant to the Sealed Air Settlement;
	•	Cash in the amount of $115 million to be paid by Fresenius pursuant to the Fresenius Settlement reduced by the amount of Fresenius' contribution to the PD Initial Payment and the ZAI Initial Payment (as described below); and
	•	Deferred payments by Grace of $110 million per year for 5 years beginning in 2019, and $100 million per year for 10 years beginning in 2024, that would be subordinate to any bank debt or bonds outstanding, guaranteed by the Company and secured by the Company's obligation to issue 50.1% of its outstanding common stock (measured as of the effective date of the Joint Plan) to the PI Trust in the event of default.
	Asbestos-Related Property Damage Claims
	All pending and future asbestos-related property damage claims and demands ("PD Claims") would be channeled to the PD Trust for resolution. The PD Trust would contribute CDN$8.6 million to a separate Canadian ZAI PD Claims fund through which Canadian ZAI PD Claims would be resolved. The PD Trust would generally resolve U.S. ZAI PD Claims that qualify for payment by paying 55% of the claimed amount, but in no event would the PD Trust pay more per claim than 55% of $7,500 (as adjusted for inflation each year after the fifth anniversary of the effective date of the Joint Plan). The PD Trust would satisfy other allowed PD Claims pursuant to specified trust distribution procedures with cash payments in the allowed settlement amount. Unresolved PD Claims and future PD claims would be litigated pursuant to procedures to be approved by the Bankruptcy Court and, to the extent such claims were determined to be allowed claims, would be paid in cash by the PD Trust in the amount determined by the Bankruptcy Court.
	The PD Trust would contain two accounts, the PD account and the ZAI PD account. U.S. ZAI PD Claims would be paid from the ZAI PD account and other PD Claims would be paid from the PD account. The separate Canadian ZAI PD Claims would be paid by a separate fund established in Canada. Each account would have a separate trustee and the assets of the accounts would not be commingled. The two accounts would be funded as follows:
	The PD account would be funded with:
	•	Approximately $152 million in cash plus cash in the amount of the estimated first six months of PD Trust expenses, to be paid by Cryovac and Fresenius (the "PD Initial Payment"), and CDN$8.6 million in cash to be paid by Grace pursuant to the Canadian ZAI Settlement.
	•	A Grace obligation (the "PD Obligation") providing for a payment to the PD Trust every six months in the amount of the non-ZAI PD Claims allowed during the preceding six months plus interest and, except for the first six months, the amount of PD Trust expenses for the preceding six months. The aggregate amount to be paid under the PD Obligation would not be capped.
	The ZAI PD account would be funded as follows (the "ZAI Assets"):
	•	$30 million in cash plus interest from April 1, 2009, to the effective date of the Joint Plan, to be paid by Cryovac and Fresenius (the "ZAI Initial Payment").
	•	$30 million in cash on the third anniversary of the effective date of the Joint Plan, to be paid by Grace.
	•	A Grace obligation providing for the payment of up to 10 contingent deferred payments of $8 million per year during the 20-year period beginning on the fifth anniversary of the effective date of the Joint Plan, with each such payment due only if the ZAI Assets fall below $10 million during the preceding year.
	All payments to the PD Trust that were not to be paid on the effective date of the Joint Plan would be secured by the Company's obligation to issue 50.1% of its outstanding common stock (measured as of the effective date of the Joint Plan) to the PD Trust in the event of default. Grace would have the right to conduct annual audits of the books, records and claim processing procedures of the PD Trust.
	Other Claims
	All allowed administrative claims would be paid in cash and all allowed priority claims would be paid in cash with interest. Secured claims would be paid in cash with interest or by reinstatement. Allowed general unsecured claims would be paid in cash, including any post-petition interest as follows: (i) for holders of pre-petition bank credit facilities, post-petition interest at the rate of 6.09% from the Filing Date through December 31, 2005, and thereafter at floating prime, in each case compounded quarterly; and (ii) for all other unsecured claims that are not subject to a settlement agreement providing otherwise, interest at 4.19% from the Filing Date, compounded annually, or if pursuant to an existing contract, interest at the non-default contract rate. The general unsecured creditors that hold pre-petition bank debt have argued that they are entitled to post-petition interest at the default rate specified under the terms of the underlying credit agreements, which they asserted was approximately an additional $185 million as of December 31, 2012, and growing (Grace believes that if default interest was ultimately determined to be payable, the additional amount of accrued interest would be substantially less than that asserted by the pre-petition bank debt holders). The Bankruptcy Court and the District Court have overruled this assertion and the pre-petition bank debt holders have appealed these rulings to the Third Circuit. Unsecured employee-related claims such as pension, retirement medical obligations and workers compensation claims would be reinstated.
	Effect on Company Common Stock
	The Joint Plan provides that Company common stock will remain outstanding at the effective date of the Joint Plan, but that the interests of existing shareholders would be subject to dilution in the event of default with respect to the deferred payment obligations to the PI Trust or the PD Trust under the Company's security obligation.
	In order to preserve significant tax benefits which are subject to elimination or limitation in the event of a change in control (as defined by the Internal Revenue Code) of Grace, the Joint Plan provides that under certain circumstances, the Board of Directors would have the authority to impose restrictions on the transfer of Grace common stock with respect to certain 5% shareholders. These restrictions will generally not limit the ability of a person that holds less than 5% of Grace common stock after emergence to either buy or sell stock on the open market. In addition, the Bankruptcy Court has approved trading restrictions on Grace common stock until the effective date of a plan of reorganization. These restrictions prohibit (without the consent of the Company) a person from acquiring more than 4.75% of the outstanding Grace common stock or, for any person already holding more than 4.75%, from increasing such person's holdings. This summary of the stock transfer restrictions does not purport to be complete and is qualified in its entirety by reference to the order of the Bankruptcy Court, which has been filed with the SEC.
	On October 25, 2012, Grace reached agreement with the PI Committee, the PI FCR and the Equity Committee to settle the warrant in cash during the one-year period after the effective date of the Joint Plan. Under the terms of the agreement, Grace will repurchase the warrant issued to the PI Trust for a price equal to the average of the daily closing prices of Grace common stock during the period commencing one day after the effective date of the Joint Plan and ending on the day prior to the date the PI Trust elects to sell the warrant back to Grace, multiplied by 10 million (the number of shares issuable under the warrant), less $170 million (the aggregate exercise price of the warrant), provided that if the average of the daily closing prices is less than $54.50 per share, then the repurchase price would be $375 million, and if the average of the daily closing prices exceeds $66.00 per share, then the repurchase price would be $490 million. The agreement is terminable by the PI Trust in the event a tender offer, or other proposed transaction that would result in a change in control of the Company, is announced during the one year period after the effective date of the Joint Plan. In such event, the warrant would be settled in stock. The agreement was approved by the Bankruptcy Court on December 11, 2012.
	Claims Filings    The Bankruptcy Court established a claims bar date of March 31, 2003, for claims of general unsecured creditors, PD Claims (other than ZAI PD Claims) and medical monitoring claims related to asbestos. The March 31, 2003, claims bar date did not apply to PI Claims or claims related to ZAI PD Claims.
	Approximately 14,900 proofs of claim were filed by the March 31, 2003, claims bar date. Of these claims, approximately 9,500 were non-asbestos-related, approximately 4,400 were PD Claims, and approximately 1,000 were for medical monitoring. Under the Joint Plan, the medical monitoring claims would be channeled to the PI Trust for resolution. In addition, approximately 800 proofs of claim were filed after the claims bar date.
	Approximately 6,940 non-asbestos-related claims were filed by employees or former employees (the "Employee Claims") for benefits arising from Grace's employee benefit plans. As of September 30, 2013, approximately 170 of these claims remain pending and are to be addressed through the claim objection process and the dispute resolution procedures approved by the Bankruptcy Court.
	The remaining non-asbestos, non-employee-related claims include claims for amounts due under pre-petition credit facilities, leases and other contracts, environmental remediation, taxes, and non-asbestos-related personal injury. As of September 30, 2013, of the approximately 3,300 of these claims filed, approximately 115 claims remain pending and are to be addressed through the claim objection process and the dispute resolution procedures approved by the Bankruptcy Court. As of September 30, 2013, of the approximately 4,335 non-ZAI PD Claims filed, approximately 20 claims remain pending and are to be addressed through the property damage case management order approved by the Bankruptcy Court and/or the Joint Plan or another plan of reorganization.
	Additionally, by order dated June 17, 2008, the Bankruptcy Court established October 31, 2008, as the claims bar date for ZAI PD Claims related to property located in the U.S. Approximately 17,960 U.S. ZAI PD Claims were filed prior to the October 31, 2008, claims bar date and, as of September 30, 2013, an additional 1,310 U.S. ZAI PD Claims were filed subsequent to that bar date. Under the Canadian ZAI Settlement, all Canadian ZAI PD Claimants who filed a proof of claim by December 31, 2009, would be entitled to seek compensation from the Canadian ZAI PD Claims Fund. Approximately 14,100 Canadian ZAI PD Claims were filed by the December 31, 2009, bar date and as of September 30, 2013, an additional 220 Canadian ZAI PD Claims were filed subsequent to that bar date. The Joint Plan provides for the channeling of U.S. ZAI PD Claims and Canadian ZAI PD Claims to the PD Trust created under the Joint Plan, and the subsequent transfer of Canadian ZAI PD Claims to a separate Canadian fund. No claims bar date has been set for personal injury claims related to ZAI. The Joint Plan provides that ZAI PI Claims would be channeled to the PI Trust created under the Joint Plan.
	Grace is continuing to analyze and review unresolved claims in relation to the Joint Plan. Grace believes that its recorded liabilities for claims subject to the March 31, 2003, claims bar date represent a reasonable estimate of the ultimate allowable amount for claims that are not in dispute or have been submitted with sufficient information to both evaluate the merit and estimate the value of the claim. The PD Claims are considered as part of Grace's overall asbestos liability and are being accounted for as described in Note 3.
	Debt Capital    All of the Debtors' pre-petition debt is in default due to the Filing. The accompanying Consolidated Balance Sheets reflect the classification of the Debtors' pre-petition debt within "liabilities subject to compromise."
	Grace maintains a $100 million cash-collateralized letter of credit facility with a commercial bank to support existing and new financial assurances.
	Accounting Impact    The accompanying Consolidated Financial Statements have been prepared in accordance with ASC 852 "Reorganizations". ASC 852 requires that financial statements of debtors-in-possession be prepared on a going concern basis, which contemplates continuity of operations and realization of assets and liquidation of liabilities in the ordinary course of business. However, as a result of the Filing, the realization of certain of the Debtors' assets and the liquidation of certain of the Debtors' liabilities are subject to significant uncertainty. While operating as debtors-in-possession, the Debtors may sell or otherwise dispose of assets and liquidate or settle liabilities for amounts other than those reflected in the Consolidated Financial Statements. Further, the ultimate plan of reorganization could materially change the amounts and classifications reported in the Consolidated Financial Statements.
	Pursuant to ASC 852, Grace's pre-petition and future liabilities that are subject to compromise are required to be reported separately on the balance sheet at an estimate of the amount that will ultimately be allowed by the Bankruptcy Court. As of September 30, 2013, such pre-petition liabilities include fixed obligations (such as debt and contractual commitments), as well as estimates of costs related to contingent liabilities (such as asbestos-related litigation, environmental remediation and other claims). Obligations of Grace subsidiaries not covered by the Filing continue to be classified on the Consolidated Balance Sheets based upon maturity dates or the expected dates of payment. ASC 852 also requires separate reporting of certain expenses, realized gains and losses, and provisions for losses related to the Filing as reorganization items. Grace presents reorganization items as "Chapter 11 expenses, net of interest income," a separate caption in its Consolidated Statements of Operations.
	Grace has not recorded the benefit of any assets that may be available to fund asbestos-related and other liabilities under the Fresenius Settlement and the Sealed Air Settlement, as under the Joint Plan, these assets will be transferred to the PI Trust and the PD Trust. The estimated fair value available under the Fresenius Settlement and the Sealed Air Settlement as measured at September 30, 2013, was $1,517 million, composed of $115 million in cash from Fresenius and $1,402 million in cash and stock from Cryovac under the Joint Plan. Payments under the Sealed Air Settlement will be made directly to the PI Trust and the PD Trust by Cryovac.
	Grace's Consolidated Balance Sheets separately identify the liabilities that are "subject to compromise" as a result of the Chapter 11 proceedings. In Grace's case, "liabilities subject to compromise" represent both pre-petition and future liabilities as determined under U.S. GAAP. Changes to pre-petition liabilities subsequent to the Filing Date reflect: (1) cash payments under approved court orders; (2) the terms of the Joint Plan, as discussed above and in Note 3, including the accrual of interest on pre-petition debt and other fixed obligations; (3) accruals for employee-related programs; and (4) changes in estimates related to other pre-petition contingent liabilities. The accounting for the asbestos-related liability component of "liabilities subject to compromise" is described in Note 3.
	Components of liabilities subject to compromise are as follows:
	(In millions)	September 30,			December 31,
		2013			2012
	Asbestos-related contingencies	$	2,065.00		$	2,065.00
	Pre-petition bank debt plus accrued interest	960.1			937.2
	Environmental contingencies	134			140.5
	Unfunded special pension arrangements	127.4			134.3
	Income tax contingencies	85.4			87.6
Postretirement benefits other than pension	58.4			63.9
Drawn letters of credit plus accrued interest	37.4			36.1
Accounts payable	31.3			31.3
Retained obligations of divested businesses	29.6			29
Other accrued liabilities	108.8			102.3
Reclassification to current liabilities(1)	(11.0		)	(10.1		)
Total Liabilities Subject to Compromise	$	3,626.40		$	3,617.10
_______________________________________________________________________________
-1	As of September 30, 2013, and December 31, 2012, approximately $11.0 million and $10.1 million, respectively, of certain pension and postretirement benefit obligations subject to compromise have been presented in "other current liabilities" in the Consolidated Balance Sheets in accordance with ASC 715 "Compensation—Retirement Benefits".
Note that the unfunded special pension arrangements reflected above exclude non-U.S. pension plans and qualified U.S. pension plans that became underfunded subsequent to the Filing. Contributions to qualified U.S. pension plans are subject to Bankruptcy Court approval.
Change in Liabilities Subject to Compromise
The following table is a reconciliation of the changes in pre-filing date liability balances for the period from the Filing Date through September 30, 2013.
(In millions) (Unaudited)	Cumulative
	Since Filing
Balance, Filing Date April 2, 2001	$	2,366.00
Cash disbursements and/or reclassifications under Bankruptcy Court orders:
Payment of environmental settlement liability	(252.0		)
Freight and distribution order	(5.7		)
Trade accounts payable order	(9.1		)
Resolution of contingencies subject to Chapter 11	(130.0		)
Other court orders for payments of certain operating expenses	(395.4		)
Expense (income) items:
Interest on pre-petition liabilities	578
Employee-related accruals	125.2
Provision for asbestos-related contingencies	1,109.80
Provision for environmental contingencies	359
Release of income tax contingencies	(82.7		)
Balance sheet reclassifications	(36.7		)
Balance, end of period	$	3,626.40
Additional liabilities subject to compromise may arise due to the rejection of executory contracts or unexpired leases, or as a result of the Bankruptcy Court's allowance of contingent or disputed claims.
For the holders of pre-petition bank credit facilities, beginning January 1, 2006, Grace agreed to pay interest on pre-petition bank debt at the prime rate, adjusted for periodic changes, and compounded quarterly. The effective rate for the nine months ended September 30, 2013 and 2012, was 3.25%. From the Filing Date through December 31, 2005, Grace accrued interest on pre-petition bank debt at a negotiated fixed annual rate of 6.09%, compounded quarterly. The pre-petition bank debt holders have argued that they are entitled to post-petition interest at the default rate specified under the terms of the underlying credit agreements, which they asserted was approximately an additional $185 million as of December 31, 2012, and growing (Grace believes that if default interest was ultimately determined to be payable, the additional amount of accrued interest would be substantially less than that asserted by the pre-petition bank debt holders). The Bankruptcy Court and the District Court have overruled this assertion and the pre-petition bank debt holders have appealed these rulings to the Third Circuit.
For the holders of claims who, but for the Filing, would be entitled under a contract or otherwise to accrue or be paid interest on such claim in a non-default (or non-overdue payment) situation under applicable non-bankruptcy law, Grace accrues interest at the rate provided in the contract between the Grace entity and the claimant or such rate as may otherwise apply under applicable non-bankruptcy law.
For all other holders of allowed general unsecured claims, Grace accrues interest at a rate of 4.19% per annum, compounded annually, unless otherwise negotiated during the claim settlement process.
Chapter 11 Expenses
	Three Months Ended September 30,						Nine Months Ended September 30,
(In millions)	2013			2012			2013			2012
Legal and financial advisory fees	$	3.6		$	4.6		$	12.4		$	13.2
Interest income	(0.7		)	(0.2		)	(1.4		)	(0.6		)
Chapter 11 expenses, net of interest income	$	2.9		$	4.4		$	11		$	12.6
Pursuant to ASC 852, interest income earned on the Debtors' cash balances must be offset against Chapter 11 expenses.
Condensed Financial Information of the Debtors
W. R. Grace & Co.—Chapter 11 Filing Entities
Debtor-in-Possession Statements of Operations
	Nine Months Ended September 30,
(In millions) (Unaudited)	2013			2012
Net sales, including intercompany	$	1,077.10		$	1,153.80
Cost of goods sold, including intercompany, exclusive of depreciation and amortization shown separately below	659			685.2
Selling, general and administrative expenses	175.5			192.8
Defined benefit pension expense	35.9			38
Depreciation and amortization	51.4			50.4
Chapter 11 expenses, net of interest income	11			12.6
Libby medical program settlement	—			19.6
Research and development expenses	27.8			26.8
Interest expense and related financing costs	28.1			30.8
Restructuring expenses	4.8			2.5
Provision for environmental remediation	3.8			1.1
Other income, net	(52.2		)	(63.2		)
	945.1			996.6
Income before income taxes and equity in net income of non-filing entities	132			157.2
Provision for income taxes	(52.9		)	(60.4		)
Income before equity in net income of non-filing entities	79.1			96.8
Equity in net income of non-filing entities	126			108.9
Net income attributable to W. R. Grace & Co. shareholders	$	205.1		$	205.7
W. R. Grace & Co.—Chapter 11 Filing Entities
Debtor-in-Possession Statements of Cash Flows
	Nine Months Ended September 30,
(In millions) (Unaudited)	2013			2012
Operating Activities
Net income attributable to W. R. Grace & Co. shareholders	$	205.1		$	205.7
Reconciliation to net cash provided by operating activities:
Depreciation and amortization	51.4			50.4
Equity in net income of non-filing entities	(126.0		)	(108.9		)
Provision for income taxes	52.9			60.4
Income taxes paid, net of refunds	(3.6		)	(2.9		)
Libby medical program settlement	—			19.6
Libby medical program settlement paid	—			(19.6		)
Excess tax benefits from stock-based compensation	33.7			(23.0		)
Interest accrued on pre-petition liabilities subject to compromise	28.1			30
Defined benefit pension expense	35.9			38
Payments under defined benefit pension arrangements	(54.2		)	(113.5		)
Changes in assets and liabilities, excluding the effect of foreign currency translation:
Trade accounts receivable	(7.5		)	(7.6		)
Inventories	(31.8		)	45
Accounts payable	7.5			(7.2		)
All other items, net	14.8			(22.3		)
Net cash provided by operating activities	206.3			144.1
Investing Activities
Capital expenditures	(68.6		)	(63.4		)
Transfer to short-term investments	(500.0		)	—
Transfer from (to) restricted cash and cash equivalents	(11.2		)	(13.2		)
Net cash used for investing activities	(579.8		)	(76.6		)
Financing Activities
Net repayments under credit arrangements	(0.3		)	(0.4		)
Proceeds from exercise of stock options	31.7			25.7
Excess tax benefits from stock-based compensation	(33.7		)	23
Net cash (used for) provided by financing activities	(2.3		)	48.3
Net (decrease) increase in cash and cash equivalents	(375.8		)	115.8
Cash and cash equivalents, beginning of period	1,064.20			788.6
Cash and cash equivalents, end of period	$	688.4		$	904.4
W. R. Grace & Co.—Chapter 11 Filing Entities
Debtor-in-Possession Balance Sheets
(In millions) (Unaudited)	September 30,			31-Dec-12
	2013
ASSETS
Current Assets
Cash and cash equivalents	$	688.4		$	1,064.20
Short-term investments	500			—
Restricted cash and cash equivalents	129.5			118.3
Trade accounts receivable, net	140.1			132.6
Accounts receivable—unconsolidated affiliate	14.9			14.1
Receivables from non-filing entities, net	154.1			160.5
Inventories	138.1			106.3
Other current assets	15.7			58.5
Total Current Assets	1,780.80			1,654.50
Properties and equipment, net	449.5			433.5
Deferred income taxes	788			935.5
Asbestos-related insurance	500			500
Loans receivable from non-filing entities, net	286.5			282.1
Investment in non-filing entities	556.3			449.5
Investment in unconsolidated affiliate	90.8			85.5
Other assets	58.1			47.2
Total Assets	$	4,510.00		$	4,387.80
LIABILITIES AND EQUITY
Liabilities Not Subject to Compromise
Current liabilities (including $15.0 due to unconsolidated affiliate) (2012—$6.0)	$	209.6		$	244.7
Underfunded defined benefit pension plans	13.4			161
Other liabilities (including $24.1 due to unconsolidated affiliate) (2012—$22.4)	58.7			56.5
Total Liabilities Not Subject to Compromise	281.7			462.2
Liabilities Subject to Compromise	3,626.40			3,617.10
Total Liabilities	3,908.10			4,079.30
Total W. R. Grace & Co. Shareholders' Equity	601.8			308.4
Noncontrolling interests in Chapter 11 filing entities	0.1			0.1
Total Equity	601.9			308.5
Total Liabilities and Equity	$	4,510.00		$	4,387.80
In addition to Grace's financial reporting obligations as prescribed by the SEC, the Debtors are also required, under the rules and regulations of the Bankruptcy Code, to periodically file certain statements and schedules with the Bankruptcy Court. This information is available to the public through the Bankruptcy Court. This information is prepared in a format that may not be comparable to information in Grace's quarterly and annual financial statements as filed with the SEC. These statements and schedules are not audited and do not purport to represent the financial position or results of operations of Grace on a consolidated basis.

AsbestosRelated_Litigation

Asbestos-Related Litigation	9 Months Ended
	Sep. 30, 2013
Asbestos-Related Litigation	'
Asbestos-Related Litigation	'
	Asbestos-Related Litigation
	Grace is a defendant in property damage and personal injury lawsuits relating to previously sold asbestos-containing products. As of the Filing Date, Grace was a defendant in 65,656 asbestos-related lawsuits, 17 involving claims for property damage (one of which has since been dismissed), and the remainder involving 129,191 claims for personal injury. Due to the Filing, holders of asbestos-related claims are stayed from continuing to prosecute pending litigation and from commencing new lawsuits against the Debtors. Grace's obligations with respect to present and future asbestos claims will be determined through the Chapter 11 process.
	Property Damage Litigation    The plaintiffs in asbestos property damage lawsuits generally seek to have the defendants pay for the cost of removing, containing or repairing the asbestos-containing materials in the affected buildings. Various factors can affect the merit and value of PD Claims, including legal defenses, product identification, the amount and type of product involved, the age, type, size and use of the building, the legal status of the claimant, the jurisdictional history of prior cases, the court in which the case is pending, and the difficulty of asbestos abatement, if necessary.
	Out of 380 asbestos property damage cases (which involved thousands of buildings) filed prior to the Filing Date, 16 remain unresolved. Eight cases relate to ZAI and eight relate to a number of former asbestos-containing products (two of which also are alleged to involve ZAI).
	Approximately 4,400 additional PD claims were filed prior to the March 31, 2003, claims bar date established by the Bankruptcy Court. (The March 31, 2003, claims bar date did not apply to ZAI claims.) Grace objected to virtually all PD claims on a number of legal and factual bases. As of September 30, 2013, approximately 430 PD Claims subject to the March 31, 2003, claims bar date remain outstanding. The Bankruptcy Court has approved settlement agreements covering approximately 410 of such claims for an aggregate allowed amount of $151.7 million.
	Eight of the ZAI cases were filed as purported class action lawsuits in 2000 and 2001. In addition, 10 lawsuits were filed as purported class actions in 2004 and 2005 with respect to persons and homes in Canada. These cases seek damages and equitable relief, including the removal, replacement and/or disposal of all such insulation. The plaintiffs assert that this product is in millions of homes and that the cost of removal could be several thousand dollars per home. As a result of the Filing, all of these cases have been stayed.
	Based on Grace's investigation of the claims described in these lawsuits, and testing and analysis of this product by Grace and others, Grace believes that ZAI was and continues to be safe for its intended purpose and poses little or no threat to human health. The plaintiffs in the ZAI lawsuits dispute Grace's position on the safety of ZAI. In December 2006, the Bankruptcy Court issued an opinion and order holding that, although ZAI is contaminated with asbestos and can release asbestos fibers when disturbed, there is no unreasonable risk of harm from ZAI. In the event the Joint Plan does not become effective, the ZAI claimants have reserved their right to appeal such opinion and order if and when it becomes a final order.
	At the Debtors' request, in July 2008, the Bankruptcy Court established a claims bar date for U.S. ZAI PD Claims and approved a related notice program that required any person with a U.S. ZAI PD Claim to submit an individual proof of claim no later than October 31, 2008. Approximately 17,960 U.S. ZAI PD Claims were filed prior to the October 31, 2008, claims bar date, and as of September 30, 2013, an additional 1,310 U.S. ZAI PD Claims were filed. As described above, under the Canadian ZAI Settlement, all Canadian ZAI PD Claims filed before December 31, 2009, would be eligible to seek compensation from the Canadian ZAI property damage claims fund. Approximately 14,100 Canadian ZAI PD Claims were filed by the December 31, 2009 bar date, and as of September 30, 2013, an additional 220 Canadian ZAI PD claims were filed subsequent to that bar date.
	As described in Note 2, in November 2008, the Debtors, the Putative Class Counsel to the U.S. ZAI property damage claimants, the PD FCR, and the Equity Committee reached an agreement designed to resolve all present and future U.S. ZAI PD Claims. The terms of the U.S. and Canadian ZAI agreements in principle have been incorporated into the terms of the Joint Plan and related documents.
	Upon the occurrence of the effective date under the Joint Plan, all pending and future PD Claims would be channeled for resolution to the PD Trust. PD Claims other than U.S. and Canadian ZAI PD Claims would be litigated in the Bankruptcy Court or a U.S. District Court, including all claims and defenses that would have been available to the parties prior to the filing of the Chapter 11 Cases as well as any defenses based on the March 31, 2003, claims bar date. Any claims determined to be allowed claims would be paid in cash by the PD Trust. Grace would be obligated to fund the PD Trust every six months in an amount sufficient to enable the PD Trust to pay all such allowed claims and Trust-related expenses.
	All allowed U.S. ZAI PD Claims would be paid by the PD Trust from the ZAI PD account and all allowed Canadian ZAI PD Claims would be paid by the Canadian ZAI property damage claims fund. Grace would have no liability or obligation for asbestos-related ZAI PD claims, except for its obligations to fund the PD Trust's ZAI PD account as described in Note 2.
	Personal Injury Litigation    Asbestos personal injury claimants allege adverse health effects from exposure to asbestos-containing products formerly manufactured by Grace. Historically, Grace's cost to resolve such claims has been influenced by numerous variables, including the nature of the disease alleged, product identification, proof of exposure to a Grace product, negotiation factors, the solvency of other former producers of asbestos-containing products, cross-claims by co-defendants, the rate at which new claims are filed, the jurisdiction in which the claims are filed, and the defense and disposition costs associated with these claims.
	As of the Filing Date, 129,191 PI Claims were pending against Grace. Grace believes that a substantial number of additional PI Claims would have been received between the Filing Date and September 30, 2013, had such PI Claims not been stayed by the Bankruptcy Court.
	The Bankruptcy Court entered a case management order for estimating liability for pending and future PI Claims. A trial for estimating liability for PI Claims began in January 2008 but was suspended in April 2008 as a result of the PI Settlement.
	Upon the occurrence of the effective date under the Joint Plan, all pending and future asbestos-related personal injury claims would be channeled for resolution to the PI Trust and Grace would have no liability or obligation for asbestos-related personal injury claims, except for its obligations to fund the PI Trust as described in Note 2.
	Asbestos-Related Liability    The recorded asbestos-related liability as of September 30, 2013, and December 31, 2012, was $2,065.0 million and is included in "liabilities subject to compromise" in the accompanying Consolidated Balance Sheets. Grace increased its asbestos-related liability by $365.0 million in the 2012 fourth quarter to reflect an updated estimate of the value of the consideration payable to the PI Trust and the PD Trust (the "Trusts") under the Joint Plan, assuming emergence from bankruptcy at the end of 2013. The recorded amount of the asbestos-related liability continues to represent a reasonable estimate of the value of the consideration payable to the PI Trust and the PD Trust if emergence does not occur until the 2014 first quarter.
	The components of the consideration payable to the Trusts under the Joint Plan are as follows:
	•	The warrant to acquire 10 million shares of the Company's common stock for $17.00 per share, which will be recorded at fair value on the effective date of the Joint Plan. Under the agreement to cash settle the warrant, discussed in Note 2, the warrant will have a value between $375 million and $490 million. Based on the current trading range of Company common stock and other valuation factors, Grace estimates the value of the warrant at emergence will be the maximum value of $490 million.
	•	The deferred payment obligation of $110 million per year for five years beginning January 2, 2019, and of $100 million per year for ten years beginning January 2, 2024, which will be recorded at fair value on the effective date of the Joint Plan. The recorded fair value of the deferred payment obligation of $547 million is within the reasonable range of possible valuations of this obligation at emergence. The value of the deferred payment obligation is affected by (i) interest rates; (ii) the Company's credit standing and the payment period of the deferred payments; (iii) restrictive covenants and terms of the Company's other credit facilities; (iv) assessment of the risk of a default, which if default were to occur would require Grace to issue shares of Company common stock; and (v) the subordination provisions of the deferred payment agreement.
	•	The cash payable by Grace to fund the PI and PD Trusts as discussed in Note 2, which will be recorded at fair value on the effective date of the Joint Plan. Grace estimates the fair value of these payments to be $528 million at emergence.
	•	As discussed in Note 2, proceeds with respect to all of Grace's insurance policies that provide coverage for asbestos-related claims would be transferred to the PI Trust under the Joint Plan. The recorded asbestos-related insurance receivable and related liability of $500.0 million at September 30, 2013, is within the reasonable range of possible valuations of these policies at emergence.
	Grace periodically evaluates the recorded amount of its asbestos-related liability and may further adjust the liability prior to the effective date of the Joint Plan if it determines that the currently recorded amount no longer represents a reasonable estimate of the value of the consideration payable to the Trusts under the Joint Plan. The recorded amount of the asbestos-related liabilities represents a reasonable estimate of the value of the consideration payable to the PI Trust and the PD Trust based on the range of reasonable valuations for the warrant, deferred payment obligations and other consideration payable to the PI Trust and the PD Trust under the Joint Plan as of September 30, 2013, and December 31, 2012.
	The ultimate cost of settling the asbestos-related liability will be based on the value of the consideration transferred to the Trusts at emergence and will vary from the current estimate.
	Five appeals were argued and submitted to the Third Circuit challenging the District Court order confirming the Joint Plan. Four of the five appeals have been rejected, leaving one appeal to be decided. Further appeals to the U. S. Supreme Court are possible. If any such appeals are resolved adversely to Grace and the other Joint Plan proponents, and if the Joint Plan cannot be amended to address any deficiencies identified by the Third Circuit in a manner satisfactory to Grace and the other Joint Plan proponents, the Debtors would expect to resume the estimation trial, which was suspended in April 2008 due to the PI Settlement, to determine the amount of its asbestos-related liabilities. Through the PI Claim estimation process and the continued adjudication of PD Claims, Grace would seek to demonstrate that most claims have no value because they fail to establish any significant property damage, health impairment or occupational exposure to asbestos from Grace's operations or products. If the Bankruptcy Court agreed with Grace's position on the number of, and the amounts to be paid in respect of, allowed PI Claims and PD Claims, then Grace believes that the value of its asbestos-related liability could be lower than the recorded amount. However, this outcome would be highly uncertain and would depend on a number of Bankruptcy Court rulings favorable to Grace's position. Conversely, the PI and PD Committees and the PI FCR have asserted that Grace's asbestos-related liabilities are substantially higher than the recorded amount, and in fact are in excess of Grace's business value. If the Bankruptcy Court accepted the position of the PI and PD Committees and the PI FCR, then any plan of reorganization likely would result in the loss of all or substantially all equity value by current shareholders.
	Insurance Rights    Grace holds insurance policies that provide coverage for 1962 to 1985 with respect to asbestos-related lawsuits and claims. For the most part, coverage for years 1962 through 1972 has been exhausted, leaving coverage for years 1973 through 1985 available for pending and future asbestos claims. Since 1985, insurance coverage for asbestos-related liabilities has not been commercially available to Grace. As discussed in Note 2, pursuant to the Joint Plan, proceeds with respect to all of Grace's insurance policies that provide coverage for asbestos-related claims would be transferred to the PI Trust.
	For each insurance year, Grace's coverage consists of both primary and excess coverage. With one exception, coverage disputes regarding Grace's primary insurance policies have been settled, and those settlement amounts have been paid in full.
	Grace has entered into settlement agreements, which are dependent upon the effectiveness of the Joint Plan, with underwriters of a portion of Grace's insurance coverage, which includes the unsettled primary coverage referenced in the preceding paragraph. Under most of these agreements, the insurers have agreed, subject to certain conditions, to pay to the PI Trust (directly or through an escrow arrangement) an aggregate of $396.1 million in respect of coverage under the affected policies. Under the remaining agreements, the insurers have agreed to reimburse the PI Trust, subject to certain conditions, which will result in a partial reimbursement of the claims actually paid by the PI Trust.
	Prior to filing the Chapter 11 Cases, Grace entered into settlement agreements with various excess insurance carriers that are not dependent upon the effectiveness of the Joint Plan. The unpaid maximum aggregate amount available under these settlement agreements is approximately $487 million. Grace had no agreements in place with insurers with respect to approximately $483 million of excess coverage, which are at layers of coverage that have not yet been triggered. Settlement amounts are generally payable on a percentage of the claims actually paid, which is based on a number of factors including the years over which a claimant was exposed to an asbestos-containing product. Grace estimates that eligible claims would have to exceed $4.0 billion to access the total $970 million of coverage. In the event the Joint Plan becomes effective, some of this settled and unsettled coverage will be superseded by the settlement agreements that are dependent upon the effectiveness of the Joint Plan.
	Grace has excess coverage with insolvent or non-paying insurance carriers. Non-paying carriers are those that, although technically solvent, are not currently meeting their obligations to pay claims. Grace has filed and continues to file claims in the insolvency proceedings of these carriers, and Grace periodically receives distributions from some of these insolvent carriers.
	The amount of insurance recovered on claims by the PI Trust will depend on the aggregate amount of insurance settlements on the effective date of the Joint Plan and a number of factors that will be determined at the time claims are paid including: the nature of the claim, the relevant exposure years, the timing of payment, the solvency of insurers and the legal status of policy rights. Grace estimates that the recorded amount of $500.0 million is within the reasonable range of possible valuations of these policies at emergence.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories
	Inventories are stated at the lower of cost or market, and cost is determined using FIFO. Inventories consisted of the following at September 30, 2013, and December 31, 2012:
	(In millions)	September 30,		31-Dec-12
		2013
	Raw materials	$	78.9	$	66.5
	In process	52.9		46.1
	Finished products	151.6		133.8
	Other	31.4		32.2
		$	314.8	$	278.6

Debt

Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Debt	'
	Components of Debt
	(In millions)	September 30,			31-Dec-12
		2013
	Debt payable within one year	$	86.2		$	83.4
	Debt payable after one year	$	7.4		$	13.4
	Debt Subject to Compromise
	Bank borrowings	$	500		$	500
	Accrued interest on bank borrowings	460.1			437.2
	Drawn letters of credit	26.7			26.5
	Accrued interest on drawn letters of credit	10.7			9.6
		$	997.5		$	973.3
	Weighted average interest rates on total debt	3.5		%	3.5		%
	At September 30, 2013, the fair value of Grace's debt payable within one year not subject to compromise approximated the recorded value of $86.2 million. Fair value is determined based on expected future cash flows (discounted at market interest rates), quotes from financial institutions and other appropriate valuation methodologies. At September 30, 2013, the carrying value of Grace's bank debt subject to compromise plus interest was $997.5 million. The estimated fair value of the bank debt approximates the carrying value and is estimated using Level 2 inputs; however, because such debt is subject to compromise in Grace's Chapter 11 proceeding, neither carrying values nor market values may reflect ultimate liquidation value.

Fair_Value_Measurements_and_Ri

Fair Value Measurements and Risk	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements and Risk	'
	Fair Value Measurements and Risk
	Certain of Grace's assets and liabilities are reported at fair value on a gross basis. ASC 820 "Fair Value Measurements and Disclosures" defines fair value as the value that would be received at the measurement date in the principal or "most advantageous" market. Grace uses principal market data, whenever available, to value assets and liabilities that are required to be reported at fair value.
	Grace has identified the following financial assets and liabilities that are subject to the fair value analysis required by ASC 820:
	Fair Value of Debt and Other Financial Instruments
	See Note 5 for a discussion of the fair value of Grace's debt. At September 30, 2013, the recorded values of other financial instruments such as cash equivalents, short-term investments, and trade receivables and payables approximated their fair values, based on the short-term maturities and floating rate characteristics of these instruments.
	Derivatives
	From time to time, Grace enters into commodity derivatives such as fixed-rate swaps with financial institutions to mitigate the risk of volatility of prices of natural gas or other commodities. Under fixed-rate swaps, Grace locks in a fixed rate with a financial institution for future purchases, purchases its commodity from a supplier at the prevailing market rate, and then settles with the bank for any difference in the rates, thereby "swapping" a variable rate for a fixed rate.
	The valuation of Grace's fixed-rate natural gas swaps was determined using a market approach, based on natural gas futures trading prices quoted on the New York Mercantile Exchange. Commodity fixed-rate swaps with maturities of not more than 12 months are used and designated as cash flow hedges of forecasted purchases of natural gas. Current open contracts hedge forecasted transactions until March 2014. The effective portion of the gain or loss on the commodity contracts is recorded in "accumulated other comprehensive loss" and reclassified into income in the same period or periods that the underlying commodity purchase affects income. At September 30, 2013, the contract volume, or notional amount, of the commodity contracts was 0.8 million MMBtu (million British thermal units) with a total contract value of $3.5 million.
	The valuation of Grace's natural gas call options was determined using a market approach, based on the strike price of the options and the natural gas futures trading prices quoted on the New York Mercantile Exchange. Commodity option contracts with maturities of not more than 24 months are used and designated as cash flow hedges of forecasted purchases of natural gas. Current open option contracts hedge forecasted transactions until June 2015. The effective portion of the gain or loss on the commodity contracts is recorded in "accumulated other comprehensive loss" and reclassified into income in the same period or periods that the underlying purchases affect income. At September 30, 2013, the contract volume, or notional amount, of the commodity option contracts was 7.1 million MMBtu and the natural gas futures trading price of option contracts was less than the strike price.
	The valuation of Grace's fixed-rate aluminum swaps was determined using a market approach, based on aluminum futures trading prices quoted on the London Metal Exchange. Commodity fixed-rate swaps with maturities of not more than 12 months are used and designated as cash flow hedges of forecasted purchases of aluminum. Current open contracts hedge forecasted transactions until September 2014. The effective portion of the gain or loss on the commodity contracts is recorded in "accumulated other comprehensive loss" and reclassified into income in the same period or periods that the underlying commodity purchase affects income. At September 30, 2013, the contract volume, or notional amount, of the commodity contracts was 1.7 million pounds with a total contract value of $1.6 million.
	Because Grace does business in over 40 countries, results are exposed to fluctuations in currency exchange rates. Grace seeks to minimize exposure to these fluctuations by matching sales in volatile currencies with expenditures in the same currencies, but it is not always possible to do so. From time to time Grace will use financial instruments such as currency forward contracts, options, or combinations of the two to reduce the risk of certain specific transactions. However, Grace does not have a policy of hedging all exposures, because management does not believe that such a level of hedging would be cost-effective.
	The valuation of Grace's currency exchange rate forward contracts is determined using both a market approach and an income approach. Inputs used to value currency exchange rate forward contracts consist of: (1) spot rates, which are quoted by various financial institutions; (2) forward points, which are primarily affected by changes in interest rates; and (3) discount rates used to present value future cash flows, which are based on the London Interbank Offered Rate (LIBOR) curve or overnight indexed swap rates.
	In November 2007, Grace purchased currency forward contracts to mitigate the effect of currency risk with respect to intercompany loans between its principal U.S. subsidiary and a German subsidiary. As of September 30, 2013, the total notional amount related to the remaining outstanding currency forward contracts was €194.5 million. These derivatives are not designated as hedging instruments under ASC 815 "Derivatives and Hedging".
	The following tables present the fair value hierarchy for financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2013, and December 31, 2012:
		Fair Value Measurements at
		September 30, 2013 Using
	Items Measured at Fair Value on a Recurring Basis	Total				Quoted Prices in Active Markets for Identical Assets or Liabilities				Significant Other Observable Inputs		Significant Unobservable Inputs
	(In millions)					(Level 1)				(Level 2)		(Level 3)
	Assets
	Currency derivatives	$	2.2			$	—			$	2.2	$	—
	Commodity derivatives	—				—				—		—
	Total Assets	$	2.2			$	—			$	2.2	$	—
	Liabilities
	Currency derivatives	$	10.8			$	—			$	10.8	$	—
	Commodity derivatives	0.5				—				0.5		—
	Total Liabilities	$	11.3			$	—			$	11.3	$	—
		Fair Value Measurements at
		December 31, 2012 Using
	Items Measured at Fair Value on a Recurring Basis	Total				Quoted Prices in Active Markets for Identical Assets or Liabilities				Significant Other Observable Inputs		Significant Unobservable Inputs
	(In millions)					(Level 1)				(Level 2)		(Level 3)
	Assets
	Currency derivatives	$	1.2			$	—			$	1.2	$	—
	Commodity derivatives	0.2				—				0.2		—
	Total Assets	$	1.4			$	—			$	1.4	$	—
	Liabilities
	Currency derivatives	$	5.1			$	—			$	5.1	$	—
	Commodity derivatives	0.4				—				0.4		—
	Total Liabilities	$	5.5			$	—			$	5.5	$	—
	The following tables present the location and fair values of derivative instruments included in the Consolidated Balance Sheets as of September 30, 2013, and December 31, 2012:
	Fair Values of Derivative Instruments at	Asset Derivatives						Liability Derivatives
	30-Sep-13
	(In millions)	Balance Sheet		Fair Value				Balance Sheet		Fair Value
		Location						Location
	Derivatives designated as hedging instruments under ASC 815:
	Commodity contracts	Other current assets		$	—			Other current liabilities		$	0.5
	Currency contracts	Other current assets		0.7				Other current liabilities		0.1
	Currency contracts	Other assets		1.4				Other liabilities		—
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts	Other current assets		0.1				Other current liabilities		10.7
	Total derivatives			$	2.2					$	11.3
	Fair Values of Derivative Instruments at	Asset Derivatives						Liability Derivatives
	December 31, 2012
	(In millions)	Balance Sheet		Fair Value				Balance Sheet		Fair Value
		Location						Location
	Derivatives designated as hedging instruments under ASC 815:
	Commodity contracts	Other current assets		$	0.2			Other current liabilities		$	0.4
	Currency contracts	Other current assets		1.2				Other current liabilities		0.2
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts	Other current assets		—				Other current liabilities		4.9
	Total derivatives			$	1.4					$	5.5
	The following tables present the location and amount of gains and losses on derivative instruments included in the Consolidated Statements of Operations or, when applicable, gains and losses initially recognized in other comprehensive income (loss) ("OCI") for the three and nine months ended September 30, 2013 and 2012:
	The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Three Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
	September 30, 2013					(Effective Portion)		(Effective Portion)
(In millions)
Derivatives in ASC 815 cash flow hedging relationships:
Currency contracts	$	0.3			Other income (expense)		$	0.5
Currency contracts	—				Cost of goods sold		(0.1		)
Commodity contracts	(0.1		)		Cost of goods sold		(0.3		)
Total derivatives	$	0.2					$	0.1
					Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
Derivatives not designated as hedging instruments under ASC 815:
Currency contracts					Other income (expense)		$	(9.9	)
The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Nine Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
September 30, 2013					(Effective Portion)		(Effective Portion)
(In millions)
Derivatives in ASC 815 cash flow hedging relationships:
Currency contracts	$	1			Other income (expense)		$	1.3
Currency contracts	(0.2		)		Cost of goods sold		(0.2		)
Commodity contracts	(0.4		)		Cost of goods sold		(0.1		)
Total derivatives	$	0.4					$	1
					Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
Derivatives not designated as hedging instruments under ASC 815:
Currency contracts					Other income (expense)		$	(5.8	)
The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Three Months Ended September 30, 2012	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
(In millions)					(Effective Portion)		(Effective Portion)
Derivatives in ASC 815 cash flow hedging relationships:
Currency contracts	$	0.8			Cost of goods sold		$	0.6
Commodity contracts	0.8				Cost of goods sold		(1.3		)
Total derivatives	$	1.6					$	(0.7	)
					Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
Derivatives not designated as hedging instruments under ASC 815:
Currency contracts					Other income (expense)		$	(4.4	)
The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Nine Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
September 30, 2012					(Effective Portion)		(Effective Portion)
(In millions)
Derivatives in ASC 815 cash flow hedging relationships:
Currency contracts	$	0.8			Cost of goods sold		$	0.4
Commodity contracts	(1.5		)		Cost of goods sold		(5.7		)
Total derivatives	$	(0.7	)				$	(5.3	)
					Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
Derivatives not designated as hedging instruments under ASC 815:
Currency contracts					Other income (expense)		$	3.4
Debt and Interest Rate Swap Agreements
Grace was not a party to any debt or interest rate swaps at September 30, 2013, and December 31, 2012.
Credit Risk
Grace is exposed to credit risk in its trade accounts receivable. Customers in the petroleum refining and construction industries represent the greatest exposure. Grace's credit evaluation policies, relatively short collection terms and history of minimal credit losses mitigate credit risk exposures. Grace does not generally require collateral for its trade accounts receivable, but may require a bank letter of credit in certain instances, particularly when selling to customers in cash restricted countries.
Grace may also be exposed to credit risk in its derivatives contracts. Grace monitors counterparty credit risk and currently does not anticipate nonperformance by its derivatives counterparties. Grace's derivatives contracts are with internationally recognized commercial financial institutions.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The income tax provision on 2013 forecasted annual income is estimated to be 33.9% as of September 30, 2013, compared with a benefit of 64.6% for the year ended December 31, 2012. The primary differences between these rates and the U.S. Federal corporate rate of 35% generally relate to changes in tax contingencies, certain nondeductible expenses including Chapter 11 expenses, tax rate differences in foreign jurisdictions and other discrete adjustments. In addition, the 2012 benefit was primarily due to the $365.0 million charge to increase the asbestos-related liability, the release of the state valuation allowance, and the utilization of domestic production activity incentives.
	Grace generally has not had to pay U.S. Federal income taxes in cash in recent years since available tax deductions and credits have fully offset U.S. taxable income.
	Grace files U.S. Federal income tax returns as well as income tax returns in various state and foreign jurisdictions. In many cases, Grace's uncertain tax positions are related to income tax returns for tax years that remain subject to examination by the relevant taxing authorities. The following table summarizes these open tax years by major jurisdiction:
	Tax Jurisdiction(1)	Examination	Examination Not
		in Progress	Yet Initiated
	United States—Federal	2007 - 2009	2010 - 2012
	United States—State	2007 - 2011	2009 - 2012
	Germany	2006 - 2008	2009 - 2012
	France	2009 - 2011	2012
	United Kingdom	None	2008 - 2012
	Italy	None	2008 - 2012
	Canada	None	2006 - 2012
	_______________________________________________________________________________
	-1	Includes federal, state, provincial or local jurisdictions, as applicable.
	Grace notes that there are attributes generated in prior years that are otherwise closed by statute and were carried forward into years that are open to examination. Those attributes may still be subject to adjustment to the extent utilized in open years.
	As a multi-national taxpayer, Grace is under continual audit by the various tax authorities on open-year tax positions. Based on the status of current examinations in various taxing jurisdictions and applicable judicial decisions applied to Grace's fact pattern, Grace believes it is reasonably possible that in the next 12 months, the amount of the liability for unrecognized tax benefits could increase by as much as $91 million, along with accelerated recognition of a deferred charge of $1 million, or decrease by as much as $78 million.
	Grace accrues potential interest and any associated penalties related to uncertain tax positions in "provision for income taxes" in the Consolidated Statements of Operations. The total amount of interest and penalties accrued on uncertain tax positions included in the Consolidated Balance Sheets was $3.9 million ($3.1 million net of applicable tax benefits) and $8.3 million ($5.5 million net of applicable tax benefits) as of September 30, 2013, and December 31, 2012, respectively.

Pension_Plans_and_Other_Postre

Pension Plans and Other Postretirement Benefit Plans	9 Months Ended
	Sep. 30, 2013
Pension and Other Postretirement Benefit Expense [Abstract]	'
Pension Plans and Other Postretirement Benefit Plans	'
	Pension Plans and Other Postretirement Benefit Plans
	Pension Plans    The following table presents the funded status of Grace's fully-funded, underfunded, and unfunded pension plans:
	(In millions)	September 30,			31-Dec-12
		2013
	Overfunded defined benefit pension plans	$	30.2		$	33.8
	Underfunded defined benefit pension plans	(30.2		)	(179.7		)
	Unfunded defined benefit pension plans	(220.6		)	(220.9		)
	Total underfunded and unfunded defined benefit pension plans	(250.8		)	(400.6		)
	Unfunded defined benefit pension plans included in liabilities subject to compromise	(121.6		)	(128.5		)
	Pension liabilities included in other current liabilities	(14.3		)	(14.0		)
	Net funded status	$	(356.5	)	$	(509.3	)
	Fully-funded plans include several advance-funded plans where the fair value of the plan assets exceeds the projected benefit obligation ("PBO"). This group of plans was overfunded by $30.2 million as of September 30, 2013, and the overfunded status is reflected as "overfunded defined benefit pension plans" in the Consolidated Balance Sheets. Underfunded plans include a group of advance-funded plans that are underfunded on a PBO basis. Unfunded plans include several plans that are funded on a pay-as-you-go basis, and therefore, the entire PBO is unfunded. The combined balance of the underfunded and unfunded plans was $386.7 million as of September 30, 2013.
	Grace maintains defined benefit pension plans covering current and former employees of certain business units and divested business units who meet age and service requirements. Benefits are generally based on final average salary and years of service. Grace funds its U.S. qualified pension plans ("U.S. qualified pension plans") in accordance with U.S. federal laws and regulations. Non-U.S. pension plans ("non-U.S. pension plans") are funded under a variety of methods, as required under local laws and customs.
	Grace also provides, through nonqualified plans, supplemental pension benefits in excess of U.S. qualified pension plan limits imposed by federal tax law. These plans cover officers and higher-level employees and serve to increase the combined pension amount to the level that they otherwise would have received under the U.S. qualified pension plans in the absence of such limits. The nonqualified plans are unfunded and Grace pays the costs of benefits as they are due to the participants.
	At the December 31, 2012, measurement date for Grace's defined benefit pension plans, the PBO was approximately $1,955 million as measured under U.S. GAAP. The PBO basis reflects the present value (using a 3.75% discount rate for U.S. plans and a 4.06% weighted average discount rate for non-U.S. plans as of December 31, 2012) of vested and non-vested benefits earned from employee service to date, based upon current services and estimated future pay increases for active employees.
	On a quarterly basis, Grace analyzes pension assets and pension liabilities along with the resulting funded status and updates its estimate of these measures. Funded status is adjusted for contributions, benefit payments, actual return on assets, current discount rates, and other identifiable and material actuarial changes. A full remeasurement is performed annually.
	The assumed discount rate for pension plans reflects the market rates for high quality corporate bonds currently available and is subject to change based on changes in the overall market interest rates. For the U.S. qualified pension plans, the assumed discount rate of 3.75% as of December 31, 2012, was selected by Grace, in consultation with its independent actuaries, based on a yield curve constructed from a portfolio of high quality bonds for which the timing and amount of cash outflows approximate the estimated payouts of the plan. Based on review of an updated yield curve analysis as of September 30, 2013, Grace increased the discount rate for the U.S. qualified pension plans from 3.75% at December 31, 2012, to 4.75% at September 30, 2013, based on market rates at that time. Grace also evaluated the current discount rates for the pension plans in the United Kingdom, Germany and Canada, which combined represented approximately 90% of the benefit obligation of the non-U.S. pension plans as of December 31, 2012. Based on review of the yield curve analyses for these plans as of September 30, 2013, Grace changed the discount rate for Germany from 3.50% at December 31, 2012, to 3.75% at September 30, 2013, and for Canada from 4.50% at December 31, 2012, to 4.75% at September 30, 2013. Grace did not change the discount rate in effect at December 31, 2012, for the United Kingdom (4.25%). The funded status as of September 30, 2013, reflects an increase in total assets of approximately $6 million and a decrease in total liabilities of approximately $159 million as compared with December 31, 2012, resulting from the change in discount rates (including the postretirement plan).
	Grace plans to change its method of accounting for deferred actuarial gains and losses relating to its global defined benefit pension plans to a more preferable method under U.S. GAAP. Grace will adopt this accounting method, referred to as mark-to-market accounting, in the 2013 fourth quarter and will retrospectively apply it to its financial results for all periods to be presented in Grace's annual report on Form 10-K for the year ended December 31, 2013.
	Postretirement Benefits Other Than Pensions    Grace provides postretirement health care and life insurance benefits for retired employees of certain U.S. business units and certain divested business units. The postretirement medical plan provides various levels of benefits to employees hired before 1993 who retire from Grace after age 55 with at least 10 years of service. These plans are unfunded and Grace pays a portion of the costs of benefits under these plans as they are incurred. Grace applies ASC 715 to these plans, which requires that the future costs of postretirement health care and life insurance benefits be accrued over the employees' years of service.
	Retirees and beneficiaries covered by the postretirement medical plan are required to contribute a minimum of 40% of the calculated premium for that coverage. During 2002, per capita costs under the retiree medical plans exceeded caps on the amount Grace was required to contribute under a 1993 amendment to the plan. As a result, for 2003 and future years, retirees will bear 100% of any increase in premium costs.
	For 2013 measurement purposes, per capita costs, before retiree contributions, were assumed to initially increase at a rate of 8.25%. The rate of increase is assumed to decrease gradually to 5% through 2020 and remain at that level thereafter. A one percentage point increase or decrease in assumed health care medical cost trend rates would not materially change Grace's postretirement benefit obligations (impact of less than $1 million) and would have a negligible impact on the aggregate of the service and interest cost components of net periodic benefit cost.
	Components of Net Periodic Benefit Cost
		Three Months Ended September 30,
		2013								2012
		Pension						Other Post		Pension						Other Post
	(In millions)	U.S.			Non-U.S.			Retirement		U.S.			Non-U.S.			Retirement
	Service cost	$	6.3		$	2.8		$	—	$	5.4		$	2.2		$	—
	Interest cost	12.9			5.1			0.5		14			5.3			0.6
	Expected return on plan assets	(17.0		)	(3.4		)	—		(15.8		)	(3.7		)	—
	Amortization of prior service cost	0.2			—			—		0.2			—			—
	Amortization of net deferred actuarial loss	9.5			1.8			0.2		8.9			1.1			0.2
	Net periodic benefit cost	$	11.9		$	6.3		$	0.7	$	12.7		$	4.9		$	0.8
		Nine Months Ended September 30,
		2013								2012
		Pension						Other Post		Pension						Other Post
	(In millions)	U.S.			Non-U.S.			Retirement		U.S.			Non-U.S.			Retirement
	Service cost	$	18.9		$	8.2		$	0.1	$	16.1		$	6.7		$	0.1
	Interest cost	38.9			15.3			1.6		42			16.1			1.9
	Expected return on plan assets	(51.0		)	(10.4		)	—		(47.4		)	(11.1		)	—
	Amortization of prior service cost	0.6			—			—		0.6			—			—
	Amortization of net deferred actuarial loss	28.5			5.9			0.4		26.7			3.5			0.5
	Net periodic benefit cost	$	35.9		$	19		$	2.1	$	38		$	15.2		$	2.5
	Plan Contributions and Funding    Subject to any required approval of the Bankruptcy Court, Grace 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 ("ERISA"). For ERISA purposes, funded status is calculated on a different basis than under U.S. GAAP. On March 11, 2013, Grace obtained Bankruptcy Court approval to make an accelerated contribution to the U.S. qualified pension plans of up to $50 million in 2013. In that regard, Grace contributed approximately $50 million in the first quarter of 2013 to the trusts that hold assets of the U.S. qualified pension plans. While Grace intends to continue to fund all minimum required payments under the U.S. qualified pension plans, there can be no assurance that the Bankruptcy Court will continue to approve these payments.
	Contributions to non-U.S. pension plans are not subject to Bankruptcy Court approval and Grace intends to fund such plans based on applicable legal requirements and actuarial and trustee recommendations.
	Grace plans to pay benefits as they become due under virtually all pay-as-you-go plans and to maintain compliance with federal funding laws for its U.S. qualified pension plans.
	Defined Contribution Retirement Plan    Grace sponsors a defined contribution retirement plan for its employees in the United States. This plan is qualified under section 401(k) of the U.S. tax code. Currently, Grace contributes an amount equal to 100% of employee contributions, up to 6% of an individual employee's salary or wages. Grace's costs related to this benefit plan for the three and nine months ended September 30, 2013, were $3.2 million and $9.9 million compared with $3.3 million and $9.9 million for the corresponding prior-year periods.

Other_Balance_Sheet_Accounts

Other Balance Sheet Accounts	9 Months Ended
	Sep. 30, 2013
Other Balance Sheet Accounts	'
Other Balance Sheet Accounts	'
	Other Balance Sheet Accounts
	(In millions)	September 30,		December 31,
		2013		2012
	Other Current Liabilities
	Accrued compensation	$	74.2	$	84.5
	Income tax payable	29		44.8
	Customer volume rebates	33.5		32.5
	Pension liabilities	14.3		14
	Accrued Chapter 11 reorganization expenses	6.4		6.6
	Accrued commissions	6.4		12.9
	Restructuring liability	5.2		3
	Fair value of currency forward and commodity contracts	11.3		5.5
	Deferred tax liability	0.6		0.6
	Other accrued liabilities	108.4		102.9
		$	289.3	$	307.3
	Accrued compensation in the table above includes salaries and wages as well as estimated current amounts due under the annual and long-term incentive programs.

Commitments_and_Contingent_Lia

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingent Liabilities	'
	Commitments and Contingent Liabilities
	See Note 3 to the Consolidated Financial Statements for a discussion of Grace's asbestos-related liability.
	Environmental Remediation    Grace 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. Grace accrues for anticipated costs associated with investigative and remediation efforts where an assessment has indicated that a probable liability has been incurred and the cost can be reasonably estimated. These accruals do not take into account any discounting for the time value of money.
	Grace's environmental liabilities are reassessed whenever circumstances become better defined or remediation efforts and their costs can be better estimated. These liabilities are evaluated based on currently available information, including the progress of remedial investigation 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.
	Estimated Investigation and Remediation Costs
	At September 30, 2013, Grace's estimated liability for environmental investigation and remediation costs (non-asbestos and asbestos-related) totaled $134.2 million, compared with $141.5 million at December 31, 2012. These amounts are based on funding and/or remediation agreements in place, including the Multi-Site Agreement described below, and Grace's estimate of costs for sites not subject to a formal remediation plan for which sufficient information is available to estimate investigation and remediation costs. These amounts do not include the cost to remediate the Libby vermiculite mine or costs related to any additional U.S. Environmental Protection Agency (EPA) claims, whether resulting from EPA's reinvestigation of vermiculite facilities or otherwise, which may be material but are not currently estimable. Due to these vermiculite-related matters, it is probable that Grace's actual investigation and remediation costs will exceed Grace's current estimates by material amounts. Net cash expenditures charged against previously established reserves for the nine months ended September 30, 2013 and 2012, were $11.2 million and $8.1 million, respectively.
	Vermiculite-Related Matters
	Grace purchased a vermiculite mine in Libby, Montana, in 1963 and operated it until 1990. Vermiculite concentrate from the Libby mine was used in the manufacture of attic insulation and other products. Some of the vermiculite ore that was mined at the Libby mine contained naturally occurring asbestos. The EPA has investigated sites, including some owned by Grace, which used, stored or processed vermiculite concentrate from the Libby mine. EPA, Grace and/or other potentially responsible parties have conducted investigations and/or remedial actions at those sites identified by EPA as requiring remedial action.
	During 2010, EPA began reinvestigating up to 105 facilities where vermiculite concentrate from the Libby mine was processed. Grace is cooperating with EPA on this reinvestigation. EPA has requested that Grace perform remediation at eight of these facilities. It is probable that EPA will request additional remediation at other facilities. Grace does not have sufficient information to identify either the sites that might require additional remediation or the cost of any additional remediation. Grace will continue to monitor EPA's reinvestigation of the remaining sites and assess any information received from EPA. A liability will be recorded in the future should Grace determine that an obligation is probable and reasonably estimable.
	Grace's total estimated liability for asbestos remediation studies and other estimable matters related to its former vermiculite operations in Libby, as well as the cost of remediation at vermiculite processing sites outside of Libby, at September 30, 2013, and December 31, 2012, was $58.3 million and $60.8 million, respectively, excluding interest where applicable. It is probable that Grace's ultimate liability will exceed current estimates by material amounts. Grace's current recorded liability will be adjusted as Grace receives new information and amounts become reasonably estimable.
	Non-Vermiculite-Related Matters
	At September 30, 2013, and December 31, 2012, Grace's estimated liability for remediation of sites not related to its former vermiculite mining and processing activities was $75.9 million and $80.7 million, respectively. This liability relates to Grace's current and former operations, including its share of liability for off-site disposal at facilities where it has been identified as a potentially responsible party. Grace's estimated liability is based upon an evaluation of claims for which sufficient information is available. As Grace receives new information and continues its claims evaluation process, its estimated liability may change materially.
	Multi-Site Settlement
	EPA filed proofs of claim with respect to potential contamination at 38 sites, including vermiculite-related claims and non-vermiculite-related claims. In June 2008, Grace entered into a multi-site settlement agreement (the "Multi-Site Agreement") with the U.S. Government, on behalf of EPA and other federal agencies. Under the Multi-Site Agreement, Grace agreed to pay approximately $44 million, which is included in the liabilities described above, to the U.S. Government and other parties in settlement of 35 of these outstanding claims and the U.S. Government has agreed not to take action against Grace under the Comprehensive Environmental Response, Compensation, and Liability Act with respect to these sites. Grace is implementing remediation at two of the remaining sites. With respect to the third remaining site, Libby, Montana, EPA's claims have been resolved except for claims related to the Grace-owned Libby vermiculite mine and the surrounding bodies of water and forest lands. Grace is cooperating with EPA to investigate these areas and determine a final remedy. The settlement amount under the Multi-Site Agreement is payable upon Grace's emergence from Chapter 11.
	Purchase Commitments    Grace uses purchase commitments to ensure supply and to minimize the volatility of major components of direct manufacturing costs including natural gas, certain metals, rare earths, asphalt, amines and other materials. Such commitments are for quantities that Grace fully expects to use in its normal operations.
	Guarantees and Indemnification Obligations    Grace is a party to many contracts containing guarantees and indemnification obligations. These contracts primarily consist of:
	•	Product warranties with respect to certain products sold to customers in the ordinary course of business. These warranties typically provide that products will conform to specifications. Grace generally does not establish a liability for product warranty based on a percentage of sales or other formula. Grace accrues a warranty liability on a transaction-specific basis depending on the individual facts and circumstances related to each sale. Both the liability and annual expense related to product warranties are immaterial to the Consolidated Financial Statements.
	•	Licenses of intellectual property by Grace to third parties in which Grace has agreed to indemnify the licensee against third party infringement claims.
	•	Contracts providing for the sale of a former business unit or product line in which Grace has agreed to indemnify the buyer against liabilities arising prior to the closing of the transaction, including environmental liabilities.
	•	Guarantees of real property lease obligations of third parties, typically arising out of (a) leases entered into by former subsidiaries of Grace, or (b) the assignment or sublease of a lease by Grace to a third party.
	Financial Assurances    Financial assurances have been established for a variety of purposes, including insurance and environmental matters, asbestos settlements and appeals, trade-related commitments and other matters. At September 30, 2013, Grace had gross financial assurances issued and outstanding of $261.7 million, composed of $108.5 million of surety bonds issued by various insurance companies and $153.2 million of standby letters of credit and other financial assurances issued by various banks; $83.8 million of these financial assurances have been issued under the letter of credit facility.
	Accounting for Contingencies    Although the outcome of each of the matters discussed above cannot be predicted with certainty, Grace has assessed its risk and has made accounting estimates as required under U.S. GAAP. As a result of the Filing, claims related to certain of the items discussed above will be addressed as part of Grace's Chapter 11 proceedings. Accruals recorded for such contingencies have been included in "liabilities subject to compromise" in the accompanying Consolidated Balance Sheets. The amounts of these liabilities as ultimately determined through the Chapter 11 proceedings could be materially different from amounts recorded at September 30, 2013.

Restructuring_Expenses_and_Rel

Restructuring Expenses and Related Asset Impairments	9 Months Ended
	Sep. 30, 2013
Restructuring and Related Activities [Abstract]	'
Restructuring Expenses and Related Asset Impairments	'
	Restructuring Expenses and Related Asset Impairments
	In the third quarter of 2013, Grace incurred cost from restructuring actions as a result of changes in the business environment and business structure. Grace incurred $3.6 million ($1.2 million in Construction Products and $2.0 million in Catalysts Technologies, and $0.4 million in Materials Technologies) of restructuring expenses and related asset impairments during the 2013 third quarter, compared with $1.1 million during the 2012 third quarter. Substantially all costs related to the restructuring programs are expected to be paid by December 31, 2014.
	Restructuring Expenses and Related Asset Impairments	Three Months Ended September 30,					Nine Months Ended September 30,
	(In millions)	2013			2012		2013		2012
	Severance and other employee related costs	$	1.5		$	0.5	$	5.7	$	5.4
	Asset impairments and other restructuring costs	2.1			0.6		3		1
	Total restructuring expenses and related asset impairments	$	3.6		$	1.1	$	8.7	$	6.4
	Restructuring Liability	Total
	(In millions)
	Balance, December 31, 2012	$	3
	Accruals for severance and other costs	6
	Payments	(3.8		)
	Balance, September 30, 2013	$	5.2

Other_Income_Expense_net

Other (Income) Expense, net	9 Months Ended
	Sep. 30, 2013
Other Income and Expenses [Abstract]	'
Other (Income) Expense, net	'
	Other (Income) Expense, net
	Components of other (income) expense, net are as follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Translation effects—intercompany loans	$	(10.1	)	$	(5.2	)	$	(6.6	)	$	2.3
	Value of currency forward contracts—intercompany loans	9.9			4.7			5.7			(4.0		)
	Currency transaction loss in Venezuela	—			—			8.5			—
	Other currency transaction effects	1.5			(0.1		)	3			0.5
	Interest income of non-Debtor subsidiaries	(0.2		)	(0.3		)	(0.5		)	(0.7		)
	Net (gain) loss on sales of investments and disposals of assets	1.1			—			—			0.3
	Other miscellaneous income	(1.5		)	(2.3		)	(5.0		)	(4.4		)
	Total other (income) expense, net	$	0.7		$	(3.2	)	$	5.1		$	(6.0	)

Other_Comprehensive_Income

Other Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Other Comprehensive Income	'
	Other Comprehensive Income (Loss)
	The following tables present the pre-tax, tax, and after-tax components of Grace's other comprehensive income (loss) for the three and nine months ended September 30, 2013 and 2012:
	Three Months Ended September 30, 2013	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.2			$	(0.2	)	$	—
	Amortization of net deferred actuarial loss included in net periodic benefit cost	11.5				(3.8		)	7.7
	Other changes in funded status	33.5				(12.4		)	21.1
	Benefit plans, net	45.2				(16.4		)	28.8
	Currency translation adjustments	5				—			5
	Gain from hedging activities	0.1				(0.1		)	—
	Other comprehensive income attributable to W. R. Grace & Co. shareholders	$	50.3			$	(16.5	)	$	33.8
	Nine Months Ended September 30, 2013	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.6			$	(0.3	)	$	0.3
	Amortization of net deferred actuarial loss included in net periodic benefit cost	34.8				(11.7		)	23.1
	Other changes in funded status	116.6				(41.7		)	74.9
	Benefit plans, net	152				(53.7		)	98.3
	Currency translation adjustments	(18.3		)		—			(18.3		)
	Loss from hedging activities	(0.6		)		0.2			(0.4		)
	Other comprehensive income attributable to W. R. Grace & Co. shareholders	$	133.1			$	(53.5	)	$	79.6
	Three Months Ended September 30, 2012	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.2			$	(0.1	)	$	0.1
	Amortization of net deferred actuarial loss included in net periodic benefit cost	10.2				(3.5		)	6.7
	Other changes in funded status	(28.4		)		8.6			(19.8		)
	Benefit plans, net	(18.0		)		5			(13.0		)
	Currency translation adjustments	14.5				—			14.5
	Gain from hedging activities	2.3				(0.8		)	1.5
	Other comprehensive income (loss) attributable to W. R. Grace & Co. shareholders	$	(1.2	)		$	4.2		$	3
	Nine Months Ended September 30, 2012	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.6			$	(0.2	)	$	0.4
	Amortization of net deferred actuarial loss included in net periodic benefit cost	30.7				(10.5		)	20.2
	Other changes in funded status	(88.8		)		27.9			(60.9		)
	Benefit plans, net	(57.5		)		17.2			(40.3		)
	Currency translation adjustments	5.1				—			5.1
	Gain from hedging activities	4.6				(1.6		)	3
	Other comprehensive loss attributable to W. R. Grace & Co. shareholders	$	(47.8	)		$	15.6		$	(32.2	)
	The following tables present the changes in accumulated other comprehensive loss, net of tax, for the nine months ended September 30, 2013 and 2012:
	Nine Months Ended September 30, 2013	Defined Benefit Pension and Other Postretirement Plans				Currency Translation Adjustments			Gains and Losses from Hedging Activities			Unrealized Loss on Investment			Total
	(In millions)
	Beginning balance	$	(641.8	)		$	35.6		$	(0.3	)	$	(0.8	)	$	(607.3	)
	Other comprehensive income (loss) before reclassifications	74.9				(18.3		)	0.4			—			57
	Amounts reclassified from accumulated other comprehensive loss	23.4				—			(0.8		)	—			22.6
	Net current-period other comprehensive income (loss)	98.3				(18.3		)	(0.4		)	—			79.6
	Ending balance	$	(543.5	)		$	17.3		$	(0.7	)	$	(0.8	)	$	(527.7	)
	Nine Months Ended September 30, 2012	Defined Benefit Pension and Other Postretirement Plans				Currency Translation Adjustments			Gains and Losses from Hedging Activities			Unrealized Loss on Investment			Total
	(In millions)
	Beginning balance	$	(605.2	)		$	30.2		$	(2.7	)	$	(0.8	)	$	(578.5	)
	Other comprehensive income (loss) before reclassifications	(60.9		)		5.1			(0.4		)	—			(56.2		)
	Amounts reclassified from accumulated other comprehensive loss	20.6				—			3.4			—			24
	Net current-period other comprehensive income (loss)	(40.3		)		5.1			3			—			(32.2		)
	Ending balance	$	(645.5	)		$	35.3		$	0.3		$	(0.8	)	$	(610.7	)
	The following tables present the amounts reclassified out of accumulated other comprehensive loss for the three and nine months ended September 30, 2013 and 2012:
	Three Months Ended September 30, 2013		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost		$	(0.2	)		Defined benefit pension expense
	Amortization of net deferred actuarial loss		(11.5		)		Defined benefit pension expense
Total before tax		(11.7		)
Tax (expense) benefit		4
Net of tax		$	(7.7	)
Gain (loss) from hedging activities
Currency contracts		$	0.5			Other income (expense)
Currency contracts		(0.1		)		Cost of goods sold
Commodity contracts		(0.3		)		Cost of goods sold
Total before tax		0.1
Tax (expense) benefit		—
Net of tax		0.1
Total reclassifications for the period, net of tax		$	(7.6	)
Nine Months Ended September 30, 2013		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
(In millions)
Defined benefit pension and other postretirement plans:
Amortization of net prior service cost		$	(0.6	)		Defined benefit pension expense
Amortization of net deferred actuarial loss		(34.8		)		Defined benefit pension expense
Total before tax		(35.4		)
Tax (expense) benefit		12
Net of tax		$	(23.4	)
Gain (loss) from hedging activities
Currency contracts		$	1.3			Other income (expense)
Currency contracts		(0.2		)		Cost of goods sold
Commodity contracts		(0.1		)		Cost of goods sold
Total before tax		1
Tax (expense) benefit		(0.2		)
Net of tax		0.8
Total reclassifications for the period, net of tax		$	(22.6	)
Three Months Ended September 30, 2012		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
(In millions)
Defined benefit pension and other postretirement plans:
Amortization of net prior service cost		$	(0.2	)		Defined benefit pension expense
Amortization of net deferred actuarial loss		(10.2		)		Defined benefit pension expense
Total before tax		(10.4		)
Tax (expense) benefit		3.6
Net of tax		$	(6.8	)
Gain (loss) from hedging activities
Currency contracts		$	0.6			Cost of goods sold
Commodity contracts		(1.3		)		Cost of goods sold
Total before tax		(0.7		)
Tax (expense) benefit		0.3
Net of tax		(0.4		)
Total reclassifications for the period, net of tax		$	(7.2	)
Nine Months Ended September 30, 2012		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
(In millions)
Defined benefit pension and other postretirement plans:
Amortization of net prior service cost		$	(0.6	)		Defined benefit pension expense
Amortization of net deferred actuarial loss		(30.7		)		Defined benefit pension expense
Total before tax		(31.3		)
Tax (expense) benefit		10.7
Net of tax		$	(20.6	)
Gain (loss) from hedging activities
Currency contracts		$	0.4			Cost of goods sold
Commodity contracts		(5.7		)		Cost of goods sold
Total before tax		(5.3		)
Tax (expense) benefit		1.9
Net of tax		(3.4		)
Total reclassifications for the period, net of tax		$	(24.0	)
Accumulated other comprehensive loss related to the defined benefit pension and other postretirement plans at September 30, 2013, and December 31, 2012, respectively, represents the accumulation of net deferred actuarial losses of $542.5 million and $640.5 million as well as net prior service costs of $1.0 million and $1.3 million. These amounts are net of tax and are amortized as a component of net periodic benefit cost.
Grace is a global enterprise operating in over 40 countries with local currency generally deemed to be the functional currency for accounting purposes. The currency translation amount represents the adjustments necessary to translate the balance sheets valued in local currencies to the U.S. dollar as of the end of each period presented, and to translate revenues and expenses at average exchange rates for each period presented.
See Note 6 for a discussion of hedging activities.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	The following table shows a reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share.
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions, except per share amounts)	2013		2012		2013		2012
	Numerators
	Net income attributable to W. R. Grace & Co. shareholders	$	69.4	$	75.5	$	205.1	$	205.7
	Denominators
	Weighted average common shares—basic calculation	76.7		75		76.2		74.7
	Dilutive effect of employee stock options	1.2		1.4		1.4		1.5
	Weighted average common shares—diluted calculation	77.9		76.4		77.6		76.2
	Basic earnings per share	$	0.9	$	1.01	$	2.69	$	2.75
	Diluted earnings per share	$	0.89	$	0.99	$	2.64	$	2.7
	There were approximately 0.4 million and 0.3 million anti-dilutive options outstanding for the three and nine months ended September 30, 2013. There were approximately 0.8 million and 0.3 million anti-dilutive options outstanding for the three and nine months ended September 30, 2012. The effect of the warrant for 10 million shares that would be issued under the Joint Plan, as discussed in Note 2, is not included in diluted earnings per share.

Operating_Segment_Information

Operating Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Operating Segment Information	'
	Operating Segment Information
	Grace is a global producer of specialty chemicals and specialty materials. Grace manages its business through three operating segments: Grace Catalysts Technologies, Grace Materials Technologies, and Grace Construction Products. Grace Catalysts Technologies includes catalysts and related products used in refining, petrochemical and other chemical manufacturing applications. Grace's Advanced Refining Technologies (ART) joint venture is managed in this segment. ART is an unconsolidated affiliate, and Grace accounts for ART using the equity method as discussed in Note 16. Grace Materials Technologies includes packaging technologies and engineered materials, coatings and sealants used in consumer, industrial, and pharmaceutical applications. Grace Construction Products includes specialty construction chemicals and specialty building materials used in commercial, infrastructure and residential construction. Intersegment sales are eliminated in consolidation. The table below presents information related to Grace's operating segments. Only those corporate expenses directly related to the operating segments are allocated for reporting purposes. All remaining corporate items are reported separately and labeled as such.
	Grace also excludes defined benefit pension expense from the calculation of segment operating income. Grace believes that the exclusion of defined benefit pension expense provides a better indicator of its operating segment performance as defined benefit pension expense is not managed at an operating segment level.
	Grace defines Adjusted EBIT (a non-GAAP financial measure) to be net income adjusted for interest income and expense, income taxes, costs related to Chapter 11, asbestos-related costs, restructuring expenses and related asset impairments, certain costs related to divested businesses, product lines, and certain other investments and gains and losses on sales of businesses, product lines, and certain other investments. In the 2013 first quarter, Grace also adjusted for the currency transaction loss incurred on our Venezuelan cash balances of $6.9 million before taxes.
	Operating Segment Data
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Net Sales
	Catalysts Technologies	$	273.7		$	298.9		$	831.1		$	939.7
	Materials Technologies	220.1			214.4			663.7			652.6
	Construction Products	277.5			263.3			789.2			765.4
	Total	$	771.3		$	776.6		$	2,284.00		$	2,357.70
	Adjusted EBIT
	Catalysts Technologies segment operating income	$	77.4		$	92		$	248.4		$	291.2
	Materials Technologies segment operating income	46.8			39.8			135.9			122.3
	Construction Products segment operating income	45.6			36.7			113.7			92.7
	Corporate costs	(20.9		)	(21.8		)	(65.4		)	(69.0		)
	Defined benefit pension expense	(18.2		)	(17.6		)	(54.9		)	(53.2		)
	Total	$	130.7		$	129.1		$	377.7		$	384
	Corporate costs include corporate support function costs and other corporate costs such as non-asbestos environmental remediation, insurance premiums and professional fees.
	Grace Adjusted EBIT for the three and nine months ended September 30, 2013 and 2012, is reconciled below to income before income taxes presented in the accompanying Consolidated Statements of Operations.
	Reconciliation of Operating Segment Data to Financial Statements
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Grace Adjusted EBIT	$	130.7		$	129.1		$	377.7		$	384
	Costs related to Chapter 11	(3.9		)	(3.7		)	(11.0		)	(11.1		)
	Asbestos-related costs	(2.5		)	(2.0		)	(6.7		)	(25.0		)
	Restructuring expenses and related asset impairments	(3.6		)	(1.1		)	(8.7		)	(6.4		)
	Certain costs related to divested businesses	(1.0		)	(0.2		)	(1.0		)	(0.4		)
	Interest expense and related financing costs	(10.7		)	(11.5		)	(32.1		)	(34.1		)
	Currency transaction loss on cash in Venezuela	—			—			(6.9		)	—
	Interest income of non-Debtor subsidiaries	0.2			0.3			0.5			0.7
	Net income attributable to noncontrolling interests	0.3			0.5			1.1			1.3
	Income before income taxes	$	109.5		$	111.4		$	312.9		$	309
	The table below presents information related to the geographic areas in which Grace operates. Sales are attributed to geographic areas based on customer location.
	Geographic Area Data
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Net Sales
	United States	$	227.6		$	222.6		$	668.7		$	663.7
	Canada and Puerto Rico	20.5			23.2			54			68
	Total North America	248.1			245.8			722.7			731.7
	Europe Middle East Africa	273.7			276.9			816.2			879.8
	Asia Pacific	155			160.4			478.7			490.1
	Latin America	94.5			93.5			266.4			256.1
	Total	$	771.3		$	776.6		$	2,284.00		$	2,357.70

Unconsolidated_Affiliate

Unconsolidated Affiliate	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Unconsolidated Affiliate	'
	Unconsolidated Affiliate
	Grace accounts for its 50% ownership interest in ART using the equity method of accounting. Grace's investment in ART amounted to $90.8 million and $85.5 million as of September 30, 2013, and December 31, 2012, respectively, and the amount included in "equity in earnings of unconsolidated affiliate" in the Consolidated Statements of Operations totaled $2.8 million and $17.1 million for the three and nine months ended September 30, 2013, compared with $4.9 million and $13.8 million for the three and nine months ended September 30, 2012.
	Grace and ART transact business on a regular basis and maintain several agreements in order to effect such business. These agreements are treated as related party activities with an unconsolidated affiliate. The table below presents summary financial data related to transactions between Grace and ART.
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Grace sales of catalysts to ART	$	69.2	$	53.4	$	174.2	$	153.1
	Charges for fixed costs, research and development and selling, general and administrative services to ART	7		7.2		22.5		22.3
	Grace and Chevron provide lines of credit in the amount of $15.0 million each at a commitment fee of 0.1% of the credit amount. These agreements expire on February 28, 2014. No amounts were outstanding at September 30, 2013, and December 31, 2012.

Noncontrolling_Interests_in_Co

Noncontrolling Interests in Consolidated Affiliates	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Noncontrolling Interests in Consolidated Affiliates	'
	Noncontrolling Interests in Consolidated Affiliates
	Grace conducts certain business activities in various countries through joint ventures with unaffiliated third parties. In certain cases, the financial results and financial position of these joint ventures are fully included in Grace's consolidated financial statements with the partner's interest reflected in noncontrolling interests in the Consolidated Statements of Operations and Consolidated Balance Sheets. The following tables present summary financial information for Grace's consolidated affiliates for which there is a noncontrolling interest:
	Statements of Operations	Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Sales	$	24.1	$	25.3	$	78	$	77
	Income before taxes	4.8		1.8		5.8		5.9
	Net income	3.6		1.5		4.8		5
	Noncontrolling interests in net income	0.3		0.5		1.1		1.3
	Balance Sheets	September 30,		December 31,
	(In millions)	2013		2012
	Cash	$	10.6	$	5.7
	Other current assets	35.8		41.6
	Total assets	78.6		73.8
	Total liabilities	53		47.2
	Shareholders' equity	25.6		26.6
	Noncontrolling interests in shareholders' equity	10.1		9.9

Subsequent_Events_Notes

Subsequent Events (Notes)	3 Months Ended
	Sep. 30, 2013
Subsequent Event [Line Items]	'
Subsequent Events [Text Block]	'
	Subsequent Event
	On October 11, 2013, Grace announced that it signed a definitive agreement to acquire the assets of the UNIPOL™ polypropylene licensing and catalysts business of The Dow Chemical Company for a cash purchase price of $500 million. This acquisition is complementary to Grace’s specialty catalysts business and significantly enhances the company’s position as a leading supplier of polyolefin catalyst technologies.

Basis_of_Presentation_and_Summ1

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies (Policies)	9 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Reclassifications and Revisions	'
	Reclassifications and Revisions    Certain amounts in prior years' Consolidated Financial Statements have been reclassified to conform to the current year presentation. Such reclassifications have not materially affected previously reported amounts in the Consolidated Financial Statements.
Use of Estimates	'
	Use of Estimates    The preparation of financial statements in conformity with U.S. generally accepted accounting principles (U.S. 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 Consolidated Financial Statements, and the reported amounts of revenues and expenses for the periods presented. Actual amounts could differ from those estimates, and the differences could be material. Changes in estimates are recorded in the period identified. Grace's accounting measurements that are most affected by management's estimates of future events are:
	•	Contingent liabilities, which depend on an assessment of the probability of loss and an estimate of ultimate resolution cost, such as asbestos-related matters and litigation (see Notes 2 and 3), income taxes (see Note 7), and environmental remediation (see Note 10);
	•	Pension and postretirement liabilities that depend on assumptions regarding participant life spans, future inflation, discount rates and total returns on invested funds (see Note 8);
	•	Realization values of net deferred tax assets and insurance receivables, which depend on projections of future income and cash flows and assessments of insurance coverage and insurer solvency; and
	•	Recoverability of goodwill, which depends on assumptions used to value reporting units, such as observable market inputs, projections of future cash flows and weighted average cost of capital. The Grace Construction Products (GCP) Europe reporting unit continues to operate in a challenging environment. While the fair value of this reporting unit exceeded the carrying value at its last testing date and management does not believe that impairment is probable, the business must continue to improve its performance in future periods, consistent with expectations, to sustain the goodwill carrying value.
	The accuracy of management's estimates may be materially affected by the uncertainties arising under Grace's Chapter 11 proceeding.

Chapter_11_Information_Tables

Chapter 11 Information (Tables)	9 Months Ended
	Sep. 30, 2013
Reorganizations [Abstract]	'
Components of liabilities subject to compromise	'
	Components of liabilities subject to compromise are as follows:
	(In millions)	September 30,			December 31,
		2013			2012
	Asbestos-related contingencies	$	2,065.00		$	2,065.00
	Pre-petition bank debt plus accrued interest	960.1			937.2
	Environmental contingencies	134			140.5
	Unfunded special pension arrangements	127.4			134.3
	Income tax contingencies	85.4			87.6
	Postretirement benefits other than pension	58.4			63.9
	Drawn letters of credit plus accrued interest	37.4			36.1
	Accounts payable	31.3			31.3
	Retained obligations of divested businesses	29.6			29
	Other accrued liabilities	108.8			102.3
	Reclassification to current liabilities(1)	(11.0		)	(10.1		)
	Total Liabilities Subject to Compromise	$	3,626.40		$	3,617.10
	_______________________________________________________________________________
	-1	As of September 30, 2013, and December 31, 2012, approximately $11.0 million and $10.1 million, respectively, of certain pension and postretirement benefit obligations subject to compromise have been presented in "other current liabilities" in the Consolidated Balance Sheets in accordance with ASC 715 "Compensation—Retirement Benefits".
Change in Liabilities Subject to Compromise	'
	The following table is a reconciliation of the changes in pre-filing date liability balances for the period from the Filing Date through September 30, 2013.
	(In millions) (Unaudited)	Cumulative
		Since Filing
	Balance, Filing Date April 2, 2001	$	2,366.00
	Cash disbursements and/or reclassifications under Bankruptcy Court orders:
	Payment of environmental settlement liability	(252.0		)
	Freight and distribution order	(5.7		)
	Trade accounts payable order	(9.1		)
	Resolution of contingencies subject to Chapter 11	(130.0		)
	Other court orders for payments of certain operating expenses	(395.4		)
	Expense (income) items:
	Interest on pre-petition liabilities	578
	Employee-related accruals	125.2
	Provision for asbestos-related contingencies	1,109.80
	Provision for environmental contingencies	359
	Release of income tax contingencies	(82.7		)
	Balance sheet reclassifications	(36.7		)
	Balance, end of period	$	3,626.40
Chapter 11 Expenses	'
	Chapter 11 Expenses
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Legal and financial advisory fees	$	3.6		$	4.6		$	12.4		$	13.2
	Interest income	(0.7		)	(0.2		)	(1.4		)	(0.6		)
	Chapter 11 expenses, net of interest income	$	2.9		$	4.4		$	11		$	12.6
Debtor-in-Possession Statements of Operations	'
	W. R. Grace & Co.—Chapter 11 Filing Entities
	Debtor-in-Possession Statements of Operations
		Nine Months Ended September 30,
	(In millions) (Unaudited)	2013			2012
	Net sales, including intercompany	$	1,077.10		$	1,153.80
	Cost of goods sold, including intercompany, exclusive of depreciation and amortization shown separately below	659			685.2
	Selling, general and administrative expenses	175.5			192.8
	Defined benefit pension expense	35.9			38
	Depreciation and amortization	51.4			50.4
	Chapter 11 expenses, net of interest income	11			12.6
	Libby medical program settlement	—			19.6
	Research and development expenses	27.8			26.8
	Interest expense and related financing costs	28.1			30.8
	Restructuring expenses	4.8			2.5
	Provision for environmental remediation	3.8			1.1
	Other income, net	(52.2		)	(63.2		)
		945.1			996.6
	Income before income taxes and equity in net income of non-filing entities	132			157.2
	Provision for income taxes	(52.9		)	(60.4		)
	Income before equity in net income of non-filing entities	79.1			96.8
	Equity in net income of non-filing entities	126			108.9
	Net income attributable to W. R. Grace & Co. shareholders	$	205.1		$	205.7
Debtor-in-Possession Statements of Cash Flows	'
	W. R. Grace & Co.—Chapter 11 Filing Entities
	Debtor-in-Possession Statements of Cash Flows
		Nine Months Ended September 30,
	(In millions) (Unaudited)	2013			2012
	Operating Activities
	Net income attributable to W. R. Grace & Co. shareholders	$	205.1		$	205.7
	Reconciliation to net cash provided by operating activities:
	Depreciation and amortization	51.4			50.4
	Equity in net income of non-filing entities	(126.0		)	(108.9		)
	Provision for income taxes	52.9			60.4
	Income taxes paid, net of refunds	(3.6		)	(2.9		)
	Libby medical program settlement	—			19.6
	Libby medical program settlement paid	—			(19.6		)
	Excess tax benefits from stock-based compensation	33.7			(23.0		)
	Interest accrued on pre-petition liabilities subject to compromise	28.1			30
	Defined benefit pension expense	35.9			38
	Payments under defined benefit pension arrangements	(54.2		)	(113.5		)
	Changes in assets and liabilities, excluding the effect of foreign currency translation:
	Trade accounts receivable	(7.5		)	(7.6		)
	Inventories	(31.8		)	45
	Accounts payable	7.5			(7.2		)
	All other items, net	14.8			(22.3		)
	Net cash provided by operating activities	206.3			144.1
	Investing Activities
	Capital expenditures	(68.6		)	(63.4		)
	Transfer to short-term investments	(500.0		)	—
	Transfer from (to) restricted cash and cash equivalents	(11.2		)	(13.2		)
	Net cash used for investing activities	(579.8		)	(76.6		)
	Financing Activities
	Net repayments under credit arrangements	(0.3		)	(0.4		)
	Proceeds from exercise of stock options	31.7			25.7
	Excess tax benefits from stock-based compensation	(33.7		)	23
	Net cash (used for) provided by financing activities	(2.3		)	48.3
	Net (decrease) increase in cash and cash equivalents	(375.8		)	115.8
	Cash and cash equivalents, beginning of period	1,064.20			788.6
	Cash and cash equivalents, end of period	$	688.4		$	904.4
Debtor-in-Possession Balance Sheets	'
	W. R. Grace & Co.—Chapter 11 Filing Entities
	Debtor-in-Possession Balance Sheets
	(In millions) (Unaudited)	September 30,			31-Dec-12
		2013
	ASSETS
	Current Assets
	Cash and cash equivalents	$	688.4		$	1,064.20
	Short-term investments	500			—
	Restricted cash and cash equivalents	129.5			118.3
	Trade accounts receivable, net	140.1			132.6
	Accounts receivable—unconsolidated affiliate	14.9			14.1
	Receivables from non-filing entities, net	154.1			160.5
	Inventories	138.1			106.3
	Other current assets	15.7			58.5
	Total Current Assets	1,780.80			1,654.50
	Properties and equipment, net	449.5			433.5
	Deferred income taxes	788			935.5
	Asbestos-related insurance	500			500
	Loans receivable from non-filing entities, net	286.5			282.1
	Investment in non-filing entities	556.3			449.5
	Investment in unconsolidated affiliate	90.8			85.5
	Other assets	58.1			47.2
	Total Assets	$	4,510.00		$	4,387.80
	LIABILITIES AND EQUITY
	Liabilities Not Subject to Compromise
	Current liabilities (including $15.0 due to unconsolidated affiliate) (2012—$6.0)	$	209.6		$	244.7
	Underfunded defined benefit pension plans	13.4			161
	Other liabilities (including $24.1 due to unconsolidated affiliate) (2012—$22.4)	58.7			56.5
	Total Liabilities Not Subject to Compromise	281.7			462.2
	Liabilities Subject to Compromise	3,626.40			3,617.10
	Total Liabilities	3,908.10			4,079.30
	Total W. R. Grace & Co. Shareholders' Equity	601.8			308.4
	Noncontrolling interests in Chapter 11 filing entities	0.1			0.1
	Total Equity	601.9			308.5
	Total Liabilities and Equity	$	4,510.00		$	4,387.80

Inventories_Tables

Inventories (Tables)	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Schedule of inventories	'
	(In millions)	September 30,		31-Dec-12
		2013
	Raw materials	$	78.9	$	66.5
	In process	52.9		46.1
	Finished products	151.6		133.8
	Other	31.4		32.2
		$	314.8	$	278.6

Debt_Tables

Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Disclosure of debt	'
	Components of Debt
	(In millions)	September 30,			31-Dec-12
		2013
	Debt payable within one year	$	86.2		$	83.4
	Debt payable after one year	$	7.4		$	13.4
	Debt Subject to Compromise
	Bank borrowings	$	500		$	500
	Accrued interest on bank borrowings	460.1			437.2
	Drawn letters of credit	26.7			26.5
	Accrued interest on drawn letters of credit	10.7			9.6
		$	997.5		$	973.3
	Weighted average interest rates on total debt	3.5		%	3.5		%

Fair_Value_Measurements_and_Ri1

Fair Value Measurements and Risk (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of assets and liabilities measured at fair value on a recurring basis	'
	The following tables present the fair value hierarchy for financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2013, and December 31, 2012:
		Fair Value Measurements at
		September 30, 2013 Using
	Items Measured at Fair Value on a Recurring Basis	Total				Quoted Prices in Active Markets for Identical Assets or Liabilities				Significant Other Observable Inputs		Significant Unobservable Inputs
	(In millions)					(Level 1)				(Level 2)		(Level 3)
	Assets
	Currency derivatives	$	2.2			$	—			$	2.2	$	—
	Commodity derivatives	—				—				—		—
	Total Assets	$	2.2			$	—			$	2.2	$	—
	Liabilities
	Currency derivatives	$	10.8			$	—			$	10.8	$	—
	Commodity derivatives	0.5				—				0.5		—
	Total Liabilities	$	11.3			$	—			$	11.3	$	—
		Fair Value Measurements at
		December 31, 2012 Using
	Items Measured at Fair Value on a Recurring Basis	Total				Quoted Prices in Active Markets for Identical Assets or Liabilities				Significant Other Observable Inputs		Significant Unobservable Inputs
	(In millions)					(Level 1)				(Level 2)		(Level 3)
	Assets
	Currency derivatives	$	1.2			$	—			$	1.2	$	—
	Commodity derivatives	0.2				—				0.2		—
	Total Assets	$	1.4			$	—			$	1.4	$	—
	Liabilities
	Currency derivatives	$	5.1			$	—			$	5.1	$	—
	Commodity derivatives	0.4				—				0.4		—
	Total Liabilities	$	5.5			$	—			$	5.5	$	—
Schedule of the location and fair values of derivative instruments included in the Consolidated Balance Sheets	'
	The following tables present the location and fair values of derivative instruments included in the Consolidated Balance Sheets as of September 30, 2013, and December 31, 2012:
	Fair Values of Derivative Instruments at	Asset Derivatives						Liability Derivatives
	30-Sep-13
	(In millions)	Balance Sheet		Fair Value				Balance Sheet		Fair Value
		Location						Location
	Derivatives designated as hedging instruments under ASC 815:
	Commodity contracts	Other current assets		$	—			Other current liabilities		$	0.5
	Currency contracts	Other current assets		0.7				Other current liabilities		0.1
	Currency contracts	Other assets		1.4				Other liabilities		—
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts	Other current assets		0.1				Other current liabilities		10.7
	Total derivatives			$	2.2					$	11.3
	Fair Values of Derivative Instruments at	Asset Derivatives						Liability Derivatives
	December 31, 2012
	(In millions)	Balance Sheet		Fair Value				Balance Sheet		Fair Value
		Location						Location
	Derivatives designated as hedging instruments under ASC 815:
	Commodity contracts	Other current assets		$	0.2			Other current liabilities		$	0.4
	Currency contracts	Other current assets		1.2				Other current liabilities		0.2
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts	Other current assets		—				Other current liabilities		4.9
	Total derivatives			$	1.4					$	5.5
Schedule of the location and amount of gains and losses on derivative instruments included in the Consolidated Statements of Operations, or initially recognized in other comprehensive income (loss) ("OCI"), when applicable	'
	The following tables present the location and amount of gains and losses on derivative instruments included in the Consolidated Statements of Operations or, when applicable, gains and losses initially recognized in other comprehensive income (loss) ("OCI") for the three and nine months ended September 30, 2013 and 2012:
	The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Three Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
	September 30, 2013					(Effective Portion)		(Effective Portion)
	(In millions)
	Derivatives in ASC 815 cash flow hedging relationships:
	Currency contracts	$	0.3			Other income (expense)		$	0.5
	Currency contracts	—				Cost of goods sold		(0.1		)
	Commodity contracts	(0.1		)		Cost of goods sold		(0.3		)
	Total derivatives	$	0.2					$	0.1
						Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts					Other income (expense)		$	(9.9	)
	The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Nine Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
	September 30, 2013					(Effective Portion)		(Effective Portion)
	(In millions)
	Derivatives in ASC 815 cash flow hedging relationships:
	Currency contracts	$	1			Other income (expense)		$	1.3
	Currency contracts	(0.2		)		Cost of goods sold		(0.2		)
	Commodity contracts	(0.4		)		Cost of goods sold		(0.1		)
	Total derivatives	$	0.4					$	1
						Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts					Other income (expense)		$	(5.8	)
	The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Three Months Ended September 30, 2012	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)					(Effective Portion)		(Effective Portion)
	Derivatives in ASC 815 cash flow hedging relationships:
	Currency contracts	$	0.8			Cost of goods sold		$	0.6
	Commodity contracts	0.8				Cost of goods sold		(1.3		)
	Total derivatives	$	1.6					$	(0.7	)
						Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts					Other income (expense)		$	(4.4	)
	The Effect of Derivative Instruments on the Consolidated Statement of Operations for the Nine Months Ended	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income		Amount of Gain or (Loss) Reclassified from Accumulated OCI into Income
	September 30, 2012					(Effective Portion)		(Effective Portion)
	(In millions)
	Derivatives in ASC 815 cash flow hedging relationships:
	Currency contracts	$	0.8			Cost of goods sold		$	0.4
	Commodity contracts	(1.5		)		Cost of goods sold		(5.7		)
	Total derivatives	$	(0.7	)				$	(5.3	)
						Location of Gain or (Loss) Recognized in Income on Derivatives		Amount of Gain or (Loss) Recognized in Income on Derivatives
	Derivatives not designated as hedging instruments under ASC 815:
	Currency contracts					Other income (expense)		$	3.4

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Schedule of open tax years by major jurisdiction	'
	The following table summarizes these open tax years by major jurisdiction:
	Tax Jurisdiction(1)	Examination	Examination Not
		in Progress	Yet Initiated
	United States—Federal	2007 - 2009	2010 - 2012
	United States—State	2007 - 2011	2009 - 2012
	Germany	2006 - 2008	2009 - 2012
	France	2009 - 2011	2012
	United Kingdom	None	2008 - 2012
	Italy	None	2008 - 2012
	Canada	None	2006 - 2012
	_______________________________________________________________________________
	-1	Includes federal, state, provincial or local jurisdictions, as applicable.

Pension_Plans_and_Other_Postre1

Pension Plans and Other Postretirement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Pension and Other Postretirement Benefit Expense [Abstract]	'
Net funded status of fully funded, underfunded, and unfunded pension plans	'
	Pension Plans    The following table presents the funded status of Grace's fully-funded, underfunded, and unfunded pension plans:
	(In millions)	September 30,			31-Dec-12
		2013
	Overfunded defined benefit pension plans	$	30.2		$	33.8
	Underfunded defined benefit pension plans	(30.2		)	(179.7		)
	Unfunded defined benefit pension plans	(220.6		)	(220.9		)
	Total underfunded and unfunded defined benefit pension plans	(250.8		)	(400.6		)
	Unfunded defined benefit pension plans included in liabilities subject to compromise	(121.6		)	(128.5		)
	Pension liabilities included in other current liabilities	(14.3		)	(14.0		)
	Net funded status	$	(356.5	)	$	(509.3	)
Components of net periodic benefit cost (income)	'
	Components of Net Periodic Benefit Cost
		Three Months Ended September 30,
		2013								2012
		Pension						Other Post		Pension						Other Post
	(In millions)	U.S.			Non-U.S.			Retirement		U.S.			Non-U.S.			Retirement
	Service cost	$	6.3		$	2.8		$	—	$	5.4		$	2.2		$	—
	Interest cost	12.9			5.1			0.5		14			5.3			0.6
	Expected return on plan assets	(17.0		)	(3.4		)	—		(15.8		)	(3.7		)	—
	Amortization of prior service cost	0.2			—			—		0.2			—			—
	Amortization of net deferred actuarial loss	9.5			1.8			0.2		8.9			1.1			0.2
	Net periodic benefit cost	$	11.9		$	6.3		$	0.7	$	12.7		$	4.9		$	0.8
		Nine Months Ended September 30,
		2013								2012
		Pension						Other Post		Pension						Other Post
	(In millions)	U.S.			Non-U.S.			Retirement		U.S.			Non-U.S.			Retirement
	Service cost	$	18.9		$	8.2		$	0.1	$	16.1		$	6.7		$	0.1
	Interest cost	38.9			15.3			1.6		42			16.1			1.9
	Expected return on plan assets	(51.0		)	(10.4		)	—		(47.4		)	(11.1		)	—
	Amortization of prior service cost	0.6			—			—		0.6			—			—
	Amortization of net deferred actuarial loss	28.5			5.9			0.4		26.7			3.5			0.5
	Net periodic benefit cost	$	35.9		$	19		$	2.1	$	38		$	15.2		$	2.5

Other_Balance_Sheet_Accounts_T

Other Balance Sheet Accounts (Tables)	9 Months Ended
	Sep. 30, 2013
Other Balance Sheet Accounts	'
Schedule of other balance sheet accounts	'
	(In millions)	September 30,		December 31,
		2013		2012
	Other Current Liabilities
	Accrued compensation	$	74.2	$	84.5
	Income tax payable	29		44.8
	Customer volume rebates	33.5		32.5
	Pension liabilities	14.3		14
	Accrued Chapter 11 reorganization expenses	6.4		6.6
	Accrued commissions	6.4		12.9
	Restructuring liability	5.2		3
	Fair value of currency forward and commodity contracts	11.3		5.5
	Deferred tax liability	0.6		0.6
	Other accrued liabilities	108.4		102.9
		$	289.3	$	307.3

Restructuring_Expenses_and_Rel1

Restructuring Expenses and Related Asset Impairments (Tables)	9 Months Ended
	Sep. 30, 2013
Restructuring and Related Activities [Abstract]	'
Schedule of restructuring expenses and related asset impairments	'
	Restructuring Expenses and Related Asset Impairments	Three Months Ended September 30,					Nine Months Ended September 30,
	(In millions)	2013			2012		2013		2012
	Severance and other employee related costs	$	1.5		$	0.5	$	5.7	$	5.4
	Asset impairments and other restructuring costs	2.1			0.6		3		1
	Total restructuring expenses and related asset impairments	$	3.6		$	1.1	$	8.7	$	6.4
Schedule of restructuring liability	'
	Restructuring Liability	Total
	(In millions)
	Balance, December 31, 2012	$	3
	Accruals for severance and other costs	6
	Payments	(3.8		)
	Balance, September 30, 2013	$	5.2

Other_Income_Expense_net_Table

Other (Income) Expense, net (Tables)	9 Months Ended
	Sep. 30, 2013
Other Income and Expenses [Abstract]	'
Schedule of other (income) expense, net	'
	Components of other (income) expense, net are as follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Translation effects—intercompany loans	$	(10.1	)	$	(5.2	)	$	(6.6	)	$	2.3
	Value of currency forward contracts—intercompany loans	9.9			4.7			5.7			(4.0		)
	Currency transaction loss in Venezuela	—			—			8.5			—
	Other currency transaction effects	1.5			(0.1		)	3			0.5
	Interest income of non-Debtor subsidiaries	(0.2		)	(0.3		)	(0.5		)	(0.7		)
	Net (gain) loss on sales of investments and disposals of assets	1.1			—			—			0.3
	Other miscellaneous income	(1.5		)	(2.3		)	(5.0		)	(4.4		)
	Total other (income) expense, net	$	0.7		$	(3.2	)	$	5.1		$	(6.0	)

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Tabular disclosure 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 Grace's other comprehensive income (loss) for the three and nine months ended September 30, 2013 and 2012:
	Three Months Ended September 30, 2013	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.2			$	(0.2	)	$	—
	Amortization of net deferred actuarial loss included in net periodic benefit cost	11.5				(3.8		)	7.7
	Other changes in funded status	33.5				(12.4		)	21.1
	Benefit plans, net	45.2				(16.4		)	28.8
	Currency translation adjustments	5				—			5
	Gain from hedging activities	0.1				(0.1		)	—
	Other comprehensive income attributable to W. R. Grace & Co. shareholders	$	50.3			$	(16.5	)	$	33.8
	Nine Months Ended September 30, 2013	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.6			$	(0.3	)	$	0.3
	Amortization of net deferred actuarial loss included in net periodic benefit cost	34.8				(11.7		)	23.1
	Other changes in funded status	116.6				(41.7		)	74.9
	Benefit plans, net	152				(53.7		)	98.3
	Currency translation adjustments	(18.3		)		—			(18.3		)
	Loss from hedging activities	(0.6		)		0.2			(0.4		)
	Other comprehensive income attributable to W. R. Grace & Co. shareholders	$	133.1			$	(53.5	)	$	79.6
	Three Months Ended September 30, 2012	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.2			$	(0.1	)	$	0.1
	Amortization of net deferred actuarial loss included in net periodic benefit cost	10.2				(3.5		)	6.7
	Other changes in funded status	(28.4		)		8.6			(19.8		)
	Benefit plans, net	(18.0		)		5			(13.0		)
	Currency translation adjustments	14.5				—			14.5
	Gain from hedging activities	2.3				(0.8		)	1.5
	Other comprehensive income (loss) attributable to W. R. Grace & Co. shareholders	$	(1.2	)		$	4.2		$	3
	Nine Months Ended September 30, 2012	Pre-Tax				Tax Benefit/			After-Tax
	(In millions)	Amount				(Expense)			Amount
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost included in net periodic benefit cost	$	0.6			$	(0.2	)	$	0.4
	Amortization of net deferred actuarial loss included in net periodic benefit cost	30.7				(10.5		)	20.2
	Other changes in funded status	(88.8		)		27.9			(60.9		)
	Benefit plans, net	(57.5		)		17.2			(40.3		)
	Currency translation adjustments	5.1				—			5.1
	Gain from hedging activities	4.6				(1.6		)	3
	Other comprehensive loss attributable to W. R. Grace & Co. shareholders	$	(47.8	)		$	15.6		$	(32.2	)
Schedule of components of accumulated other comprehensive loss	'
	The following tables present the changes in accumulated other comprehensive loss, net of tax, for the nine months ended September 30, 2013 and 2012:
	Nine Months Ended September 30, 2013	Defined Benefit Pension and Other Postretirement Plans				Currency Translation Adjustments			Gains and Losses from Hedging Activities			Unrealized Loss on Investment			Total
	(In millions)
	Beginning balance	$	(641.8	)		$	35.6		$	(0.3	)	$	(0.8	)	$	(607.3	)
	Other comprehensive income (loss) before reclassifications	74.9				(18.3		)	0.4			—			57
	Amounts reclassified from accumulated other comprehensive loss	23.4				—			(0.8		)	—			22.6
	Net current-period other comprehensive income (loss)	98.3				(18.3		)	(0.4		)	—			79.6
	Ending balance	$	(543.5	)		$	17.3		$	(0.7	)	$	(0.8	)	$	(527.7	)
	Nine Months Ended September 30, 2012	Defined Benefit Pension and Other Postretirement Plans				Currency Translation Adjustments			Gains and Losses from Hedging Activities			Unrealized Loss on Investment			Total
	(In millions)
	Beginning balance	$	(605.2	)		$	30.2		$	(2.7	)	$	(0.8	)	$	(578.5	)
	Other comprehensive income (loss) before reclassifications	(60.9		)		5.1			(0.4		)	—			(56.2		)
	Amounts reclassified from accumulated other comprehensive loss	20.6				—			3.4			—			24
	Net current-period other comprehensive income (loss)	(40.3		)		5.1			3			—			(32.2		)
	Ending balance	$	(645.5	)		$	35.3		$	0.3		$	(0.8	)	$	(610.7	)
Schedule of Amounts Reclassified Out of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	The following tables present the amounts reclassified out of accumulated other comprehensive loss for the three and nine months ended September 30, 2013 and 2012:
	Three Months Ended September 30, 2013		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost		$	(0.2	)		Defined benefit pension expense
	Amortization of net deferred actuarial loss		(11.5		)		Defined benefit pension expense
	Total before tax		(11.7		)
	Tax (expense) benefit		4
	Net of tax		$	(7.7	)
	Gain (loss) from hedging activities
	Currency contracts		$	0.5			Other income (expense)
	Currency contracts		(0.1		)		Cost of goods sold
	Commodity contracts		(0.3		)		Cost of goods sold
	Total before tax		0.1
	Tax (expense) benefit		—
	Net of tax		0.1
	Total reclassifications for the period, net of tax		$	(7.6	)
	Nine Months Ended September 30, 2013		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost		$	(0.6	)		Defined benefit pension expense
	Amortization of net deferred actuarial loss		(34.8		)		Defined benefit pension expense
	Total before tax		(35.4		)
	Tax (expense) benefit		12
	Net of tax		$	(23.4	)
	Gain (loss) from hedging activities
	Currency contracts		$	1.3			Other income (expense)
	Currency contracts		(0.2		)		Cost of goods sold
	Commodity contracts		(0.1		)		Cost of goods sold
	Total before tax		1
	Tax (expense) benefit		(0.2		)
	Net of tax		0.8
	Total reclassifications for the period, net of tax		$	(22.6	)
	Three Months Ended September 30, 2012		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost		$	(0.2	)		Defined benefit pension expense
	Amortization of net deferred actuarial loss		(10.2		)		Defined benefit pension expense
	Total before tax		(10.4		)
	Tax (expense) benefit		3.6
	Net of tax		$	(6.8	)
	Gain (loss) from hedging activities
	Currency contracts		$	0.6			Cost of goods sold
	Commodity contracts		(1.3		)		Cost of goods sold
	Total before tax		(0.7		)
	Tax (expense) benefit		0.3
	Net of tax		(0.4		)
	Total reclassifications for the period, net of tax		$	(7.2	)
	Nine Months Ended September 30, 2012		Amount of Gain or (Loss) Reclassified From Accumulated OCI				Location of Gain or (Loss) Reclassified from Accumulated OCI into Income
	(In millions)
	Defined benefit pension and other postretirement plans:
	Amortization of net prior service cost		$	(0.6	)		Defined benefit pension expense
	Amortization of net deferred actuarial loss		(30.7		)		Defined benefit pension expense
	Total before tax		(31.3		)
	Tax (expense) benefit		10.7
	Net of tax		$	(20.6	)
	Gain (loss) from hedging activities
	Currency contracts		$	0.4			Cost of goods sold
	Commodity contracts		(5.7		)		Cost of goods sold
	Total before tax		(5.3		)
	Tax (expense) benefit		1.9
	Net of tax		(3.4		)
	Total reclassifications for the period, net of tax		$	(24.0	)

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Schedule of reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share	'
	The following table shows a reconciliation of the numerators and denominators used in calculating basic and diluted earnings per share.
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions, except per share amounts)	2013		2012		2013		2012
	Numerators
	Net income attributable to W. R. Grace & Co. shareholders	$	69.4	$	75.5	$	205.1	$	205.7
	Denominators
	Weighted average common shares—basic calculation	76.7		75		76.2		74.7
	Dilutive effect of employee stock options	1.2		1.4		1.4		1.5
	Weighted average common shares—diluted calculation	77.9		76.4		77.6		76.2
	Basic earnings per share	$	0.9	$	1.01	$	2.69	$	2.75
	Diluted earnings per share	$	0.89	$	0.99	$	2.64	$	2.7

Operating_Segment_Information_

Operating Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Schedule of operating segment data	'
	Operating Segment Data
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Net Sales
	Catalysts Technologies	$	273.7		$	298.9		$	831.1		$	939.7
	Materials Technologies	220.1			214.4			663.7			652.6
	Construction Products	277.5			263.3			789.2			765.4
	Total	$	771.3		$	776.6		$	2,284.00		$	2,357.70
	Adjusted EBIT
	Catalysts Technologies segment operating income	$	77.4		$	92		$	248.4		$	291.2
	Materials Technologies segment operating income	46.8			39.8			135.9			122.3
	Construction Products segment operating income	45.6			36.7			113.7			92.7
	Corporate costs	(20.9		)	(21.8		)	(65.4		)	(69.0		)
	Defined benefit pension expense	(18.2		)	(17.6		)	(54.9		)	(53.2		)
	Total	$	130.7		$	129.1		$	377.7		$	384
Schedule of reconciliation of operating segment data to financial statements	'
	Reconciliation of Operating Segment Data to Financial Statements
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Grace Adjusted EBIT	$	130.7		$	129.1		$	377.7		$	384
	Costs related to Chapter 11	(3.9		)	(3.7		)	(11.0		)	(11.1		)
	Asbestos-related costs	(2.5		)	(2.0		)	(6.7		)	(25.0		)
	Restructuring expenses and related asset impairments	(3.6		)	(1.1		)	(8.7		)	(6.4		)
	Certain costs related to divested businesses	(1.0		)	(0.2		)	(1.0		)	(0.4		)
	Interest expense and related financing costs	(10.7		)	(11.5		)	(32.1		)	(34.1		)
	Currency transaction loss on cash in Venezuela	—			—			(6.9		)	—
	Interest income of non-Debtor subsidiaries	0.2			0.3			0.5			0.7
	Net income attributable to noncontrolling interests	0.3			0.5			1.1			1.3
	Income before income taxes	$	109.5		$	111.4		$	312.9		$	309
Schedule of geographic area data	'
		Three Months Ended September 30,						Nine Months Ended September 30,
	(In millions)	2013			2012			2013			2012
	Net Sales
	United States	$	227.6		$	222.6		$	668.7		$	663.7
	Canada and Puerto Rico	20.5			23.2			54			68
	Total North America	248.1			245.8			722.7			731.7
	Europe Middle East Africa	273.7			276.9			816.2			879.8
	Asia Pacific	155			160.4			478.7			490.1
	Latin America	94.5			93.5			266.4			256.1
	Total	$	771.3		$	776.6		$	2,284.00		$	2,357.70

Unconsolidated_Affiliate_Table

Unconsolidated Affiliate (Tables)	9 Months Ended
	Sep. 30, 2013
Equity Method Investments and Joint Ventures [Abstract]	'
Schedule of financial data related to transactions between Grace and ART	'
	The table below presents summary financial data related to transactions between Grace and ART.
		Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Grace sales of catalysts to ART	$	69.2	$	53.4	$	174.2	$	153.1
	Charges for fixed costs, research and development and selling, general and administrative services to ART	7		7.2		22.5		22.3

Noncontrolling_Interests_in_Co1

Noncontrolling Interests in Consolidated Affiliates (Tables)	9 Months Ended
	Sep. 30, 2013
Noncontrolling Interest [Abstract]	'
Schedule of condensed statements of operations for consolidated affiliates for which there is a noncontrolling interest	'
	The following tables present summary financial information for Grace's consolidated affiliates for which there is a noncontrolling interest:
	Statements of Operations	Three Months Ended September 30,				Nine Months Ended September 30,
	(In millions)	2013		2012		2013		2012
	Sales	$	24.1	$	25.3	$	78	$	77
	Income before taxes	4.8		1.8		5.8		5.9
	Net income	3.6		1.5		4.8		5
	Noncontrolling interests in net income	0.3		0.5		1.1		1.3
Schedule of condensed balance sheets for consolidated affiliates for which there is a noncontrolling interest	'
	The following tables present summary financial information for Grace's consolidated affiliates for which there is a noncontrolling interest:
	Balance Sheets	September 30,		December 31,
	(In millions)	2013		2012
	Cash	$	10.6	$	5.7
	Other current assets	35.8		41.6
	Total assets	78.6		73.8
	Total liabilities	53		47.2
	Shareholders' equity	25.6		26.6
	Noncontrolling interests in shareholders' equity	10.1		9.9

Basis_of_Presentation_and_Summ2

Basis of Presentation and Summary of Significant Accounting and Financial Reporting Policies (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Feb. 13, 2013	Dec. 31, 2012	Apr. 02, 2001
	segment						entity
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'	'	'	'	'	'	'
Number of operating segments	3	'	'	'	'	'	'
Number of United States subsidiaries and affiliates filed voluntary petitions for reorganization	'	'	'	'	'	'	61
Currency Translation	'	'	'	'	'	'	'
Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results	'	$9.60	'	'	'	'	'
Venezuela Currency Exchange Rate Point In Time	'	'	'	'	4.3	'	'
Venezuela Currency Exchange Rate Future	'	'	'	'	6.3	'	'
Currency transaction loss in Venezuela	'	'	8.5	'	'	'	'
Short-term Investments	500	0	500	0	'	0	'
Reportable Segment	'	'	'	'	'	'	'
Currency Translation	'	'	'	'	'	'	'
Currency transaction loss in Venezuela	$1.60	'	'	'	'	'	'

Chapter_11_Information_Details

Chapter 11 Information (Details)

0 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

25 Months Ended

3 Months Ended

3 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

1 Months Ended

3 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Sep. 21, 2012

Mar. 31, 2003

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2010

Sep. 30, 2012

Jun. 11, 2012

Dec. 31, 2005

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2003

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Jan. 31, 2011

Sep. 30, 2013

Dec. 31, 2009

Oct. 31, 2008

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

USD ($)

claim

USD ($)

USD ($)

occasion

item

PI Trust

PI and PD Trusts

Personal Damage Trust [Member]

Personal Damage Trust [Member]

Cryovac, Inc. ("Cryovac")

Cryovac, Inc. ("Cryovac")

Sealed Air Corporation ("Sealed Air")

Sealed Air Corporation ("Sealed Air")

Fresenius Medical Care Holdings, Inc.

Fresenius Medical Care Holdings, Inc.

Canada

Canada

Canada

United States (U.S.)

United States (U.S.)

PI and PD Committees

PI and PD FCR

Chapter 11 Filing Entities

Chapter 11 Filing Entities

trust

USD ($)

USD ($)

claim

USD ($)

Personal Damage Trust [Member]

PI Trust

USD ($)

Personal Damage Trust [Member]

CAD

Personal Damage Trust [Member]

Personal Damage Trust [Member]

Personal Damage Trust [Member]

Personal Damage Trust [Member]

committees

committees

USD ($)

USD ($)

claim

trust

payment

USD ($)

USD ($)

claim

claim

claim

claim

committees

claim

account

Chapter 11 information

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy proceedings, number of committees

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2

2

'

'

ZAI property damage claim funds

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

8,600,000

'

'

'

'

'

'

'

'

Asbestos trusts established under Bankruptcy Code

'

'

2

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of occasions for which amendments and technical modifications were filed

'

'

'

'

9

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payments to fund Joint Plan

'

'

'

'

'

'

'

'

'

'

'

'

512,500,000

'

'

'

115,000,000

'

'

'

'

'

'

'

'

'

'

Interest rate related to cash received from the entity under joint plan funding (as a percent)

'

'

'

'

'

'

'

'

5.50%

'

'

'

5.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of common stock held in trust (in shares)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

18

'

'

'

'

'

'

'

'

'

'

'

Common stock split arrangement

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'two-for-one

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims expunged, reclassified by debtors or withdrawn by claimants

'

'

'

'

'

'

8

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Appeals, Number of Appeals Pending

'

'

5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Appeals, Number of Outstanding Rulings

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Appeals, Number of favorvable rulings

'

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

One-time payment to Libby claimants under the joint plan

19,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds under Joint plan funding

'

'

'

'

'

'

'

'

250,000,000

'

152,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of warrants issued by entity to fund trust (in shares)

'

'

'

'

'

'

'

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price of warrant (in dollars per share)

'

'

'

'

'

'

'

'

$17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Expiration period of warrant

'

'

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred payments per year for five years by the entity to the Trust

'

'

'

'

'

'

'

'

110,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred payments per year for ten years by the entity to the Trust

'

'

'

'

'

'

'

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of outstanding common stock issued in the event of default

'

'

'

'

'

'

'

'

'

50.10%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of claimed amount qualified for ZAI PD claims

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

55.00%

'

'

'

'

Maximum resolved amount per claim

'

'

'

'

'

'

'

'

'

'

7,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of PD Trust accounts

'

'

'

'

'

'

'

'

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from Joint Plan Funds, Equivalent of Estimated Expenses, Period

'

'

'

'

'

'

'

'

'

'

'6 months

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

ZAI initial payment

'

'

'

'

'

'

'

'

'

'

'

'

'

30,000,000

'

'

'

30,000,000

'

'

'

'

'

'

'

'

'

Cash payment by entity to the Trust on the third anniversary of the effective date of the joint plan

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

30,000,000

'

'

'

'

'

'

'

'

'

Maximum number of deferred payments by the entity to the Trust

'

'

'

'

'

'

'

'

'

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred payments per year for twenty years by the entity to the Trust

'

'

'

'

'

'

'

'

'

'

8,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum assets fulfilling condition for payment of contingent obligation by the entity to the Trust

'

'

'

'

'

'

'

'

10,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate on pre-petition bank credit facilities (as a percent)

'

'

3.25%

'

'

3.25%

'

6.09%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Compound interest rate on unsecured claims (as a percent)

'

'

4.19%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Post-petition interest sought by general unsecured creditors

'

'

'

185,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage of shareholders on whom restrictions may be imposed for transfer of common stock

'

'

5.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum acquisition percentage of common stock

'

'

4.75%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Warrant value settlement period after the effective date of the Joint Plan

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of shares issuable under the warrant

'

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Aggregate exercise price of the warrant

'

'

170,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Closing price of common stock under condition 1 (in dollars per share)

'

'

$54.50

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase price of warrant under condition 1

'

'

375,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Closing price of common stock under condition 2 (in dollars per share)

'

'

$66

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Repurchase price of warrant under condition 2

'

'

490,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period for change in control of the entity

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Claims Filings

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims filed

'

14,900

'

'

'

'

'

'

'

'

4,335

'

'

'

'

'

'

'

'

220

14,100

'

'

'

'

'

'

Number of pending claims, medical monitoring related

'

1,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims filed after the bar date

'

'

'

'

'

'

'

'

'

'

800

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims filed by employees or former employees

'

'

6,940

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of claims filed by employees or former employees remaining pending

'

'

170

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Claims, Non Asbestos Related Pending Number

'

9,500

'

'

'

'

'

'

'

'

3,300

4,400

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of remaining claims

'

'

115

'

'

'

'

'

'

'

20

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of bankruptcy claims filed prior to a specified date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,960

'

'

'

'

'

Number of additional bankruptcy claims filed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,310

'

'

'

'

Cash-collateralized letter of credit facility

'

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated fair value available under the settlement

'

'

1,517,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asbestos related settlement in cash

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

115,000,000

'

'

'

'

'

'

'

'

'

'

Asbestos related settlement in cash and stock

'

'

'

'

'

'

'

'

'

'

'

'

1,402,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Reclassification to current liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

-11,000,000

[1]

-10,100,000

[1]

Due to Related Parties, Current

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

15,000,000

6,000,000

Due to Other Related Parties, Noncurrent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$24,100,000

$22,400,000

[1]

(1)As of September 30, 2013, and December 31, 2012, approximately $11.0 million and $10.1 million, respectively, of certain pension and postretirement benefit obligations subject to compromise have been presented in "other current liabilities" in the Consolidated Balance Sheets in accordance with ASC 715 "Compensation—Retirement Benefits".

Chapter_11_Information_Details1

Chapter 11 Information (Details 2) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

150 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Dec. 31, 2011

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Dec. 31, 2012

Apr. 02, 2001

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Chapter 11 Filing Entities

Components of liabilities subject to compromise are as follows:

'

'

'

'

'

'

'

'

'

'

'

'

'

Asbestos-related contingencies

$2,065

'

$2,065

'

$2,065

'

$2,065

'

$2,065

'

$2,065

$2,065

'

Pre-petition bank debt plus accrued interest

997.5

'

997.5

'

973.3

'

960.1

'

960.1

'

960.1

937.2

'

Environmental contingencies

134

'

134

'

140.5

'

134

'

134

'

134

140.5

'

Unfunded special pension arrangements

174.8

'

174.8

'

188.1

'

127.4

'

127.4

'

127.4

134.3

'

Income tax contingencies

85.4

'

85.4

'

87.6

'

85.4

'

85.4

'

85.4

87.6

'

Postretirement benefits other than pension

'

'

'

'

'

'

58.4

'

58.4

'

58.4

63.9

'

Drawn letters of credit plus accrued interest

'

'

'

'

'

'

37.4

'

37.4

'

37.4

36.1

'

Accounts payable

'

'

'

'

'

'

31.3

'

31.3

'

31.3

31.3

'

Retained obligations of divested businesses

'

'

'

'

'

'

29.6

'

29.6

'

29.6

29

'

Other accrued liabilities

169.7

'

169.7

'

162.6

'

108.8

'

108.8

'

108.8

102.3

'

Reclassification to current liabilities

'

'

'

'

'

'

-11

[1]

'

-11

[1]

'

-11

[1]

-10.1

[1]

'

Liabilities Subject to Compromise

3,626.40

'

3,626.40

'

3,617.10

'

3,626.40

'

3,626.40

'

3,626.40

3,617.10

'

Reconciliation of the changes in pre-filing date liability balances

'

'

'

'

'

'

'

'

'

'

'

'

'

Balance, Filing Date April 2, 2001

'

'

'

'

'

'

'

'

'

'

'

'

2,366

Cash disbursements and/or reclassifications under Bankruptcy Court orders:

'

'

'

'

'

'

'

'

'

'

'

'

'

Payment of environmental settlement liability

'

'

-11.2

-8.1

'

'

'

'

'

'

-252

'

'

Freight and distribution order

'

'

'

'

'

'

'

'

'

'

-5.7

'

'

Trade accounts payable order

'

'

'

'

'

'

'

'

'

'

-9.1

'

'

Resolution of contingencies subject to Chapter 11

'

'

'

'

'

'

'

'

'

'

-130

'

'

Other court orders for payments of certain operating expenses

'

'

'

'

'

'

'

'

'

'

-395.4

'

'

Expense/(income) items:

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest on pre-petition liabilities

'

'

'

'

'

'

'

'

'

'

578

'

'

Employee-related accruals

'

'

'

'

'

'

'

'

'

'

125.2

'

'

Provision for asbestos-related contingencies

'

'

'

'

'

'

'

'

'

'

1,109.80

'

'

Provision for environmental contingencies

'

'

'

'

'

'

'

'

'

'

359

'

'

Provision for income tax contingencies

'

'

'

'

'

'

'

'

'

'

-82.7

'

'

Balance sheet reclassifications

'

'

'

'

'

'

'

'

'

'

-36.7

'

'

Balance, end of period

'

'

'

'

'

'

3,626.40

'

3,626.40

'

3,626.40

'

2,366

Chapter 11 Expenses

'

'

'

'

'

'

'

'

'

'

'

'

'

Legal and financial advisory fees

'

'

'

'

'

'

3.6

4.6

12.4

13.2

'

'

'

Interest income

'

'

'

'

'

'

-0.7

-0.2

-1.4

-0.6

'

'

'

Chapter 11 expenses, net of interest income

2.9

4.4

11

12.6

'

'

2.9

4.4

11

12.6

'

'

'

Debtor-in-Possession Statements of Operations

'

'

'

'

'

'

'

'

'

'

'

'

'

Net sales, including intercompany

771.3

776.6

2,284

2,357.70

'

'

'

'

1,077.10

1,153.80

'

'

'

Cost of goods sold, including intercompany, exclusive of depreciation and amortization shown separately below

'

'

'

'

'

'

'

'

659

685.2

'

'

'

Selling, general and administrative expenses

125.2

130.8

391.7

401.2

'

'

'

'

175.5

192.8

'

'

'

Defined benefit pension expense

18.2

17.6

54.9

53.2

'

'

'

'

35.9

38

'

'

'

Depreciation and amortization

'

'

91.8

88.9

'

'

'

'

51.4

50.4

'

'

'

Chapter 11 expenses, net of interest income

2.9

4.4

11

12.6

'

'

2.9

4.4

11

12.6

'

'

'

Libby medical program settlement paid

0

-19.6

'

'

'

'

'

-19.6

0

19.6

'

'

'

Research and development expenses

15

15.4

48.5

47.9

'

'

'

'

27.8

26.8

'

'

'

Interest expense and related financing costs

10.7

11.5

32.1

34.1

'

'

'

'

28.1

30.8

'

'

'

Restructuring expenses

'

'

6

'

'

'

'

'

4.8

2.5

'

'

'

Provision for environmental remediation

1.7

0.6

4

1.8

'

'

'

'

3.8

1.1

'

'

'

Other income, net

0.7

-3.2

5.1

-6

'

'

'

'

-52.2

-63.2

'

'

'

Total costs and expenses

175.2

173.4

538.9

557

'

'

'

'

945.1

996.6

'

'

'

Income before income taxes and equity in net income of non-filing entities

'

'

'

'

'

'

'

'

132

157.2

'

'

'

Provision for income taxes

-39.8

-35.4

-106.7

-102

'

'

'

'

-52.9

-60.4

'

'

'

Income before equity in net income of non-filing entities

'

'

'

'

'

'

'

'

79.1

96.8

'

'

'

Equity in net income of non-filing entities

'

'

'

'

'

'

'

'

126

108.9

'

'

'

Net income attributable to W. R. Grace & Co. shareholders

69.4

75.5

205.1

205.7

'

'

'

'

205.1

205.7

'

'

'

Operating Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

Net income attributable to W. R. Grace and Co. shareholders

69.4

75.5

205.1

205.7

'

'

'

'

205.1

205.7

'

'

'

Reconciliation to net cash provided by operating activities:

'

'

'

'

'

'

'

'

'

'

'

'

'

Depreciation and amortization

'

'

91.8

88.9

'

'

'

'

51.4

50.4

'

'

'

Equity in net income of non-filing entities

'

'

'

'

'

'

'

'

-126

-108.9

'

'

'

Provision for income taxes

39.8

35.4

106.7

102

'

'

'

'

52.9

60.4

'

'

'

Income taxes paid, net of refunds

'

'

-65.6

-41.6

'

'

'

'

-3.6

-2.9

'

'

'

Libby medical program settlement

0

0.1

0

19.6

'

'

'

'

'

19.6

'

'

'

Defined benefit pension expense

18.2

17.6

54.9

53.2

'

'

'

'

35.9

38

'

'

'

Payments under defined benefit pension arrangements

'

'

-63.6

-122.5

'

'

'

'

-54.2

-113.5

'

'

'

Changes in assets and liabilities, excluding the effect of foreign currency translation:

'

'

'

'

'

'

'

'

'

'

'

'

'

Trade accounts receivable

'

'

5.2

-3.7

'

'

'

'

-7.5

-7.6

'

'

'

Inventories

'

'

-37.7

20.6

'

'

'

'

-31.8

45

'

'

'

Accounts payable

'

'

6.8

3.6

'

'

'

'

7.5

-7.2

'

'

'

All other items, net

'

'

-7.1

-10.2

'

'

'

'

14.8

-22.3

'

'

'

Net cash provided by (used for) operating activities

'

'

'

'

'

'

'

'

206.3

144.1

'

'

'

Tax benefits from stock-based compensation

33.7

-23

'

'

'

'

'

-23

'

-33.7

'

'

'

Investing Activities

'

'

'

'

'

'

'

'

'

'

'

'

'

Capital expenditures

'

'

-117.9

-103.6

'

'

'

'

-68.6

-63.4

'

'

'

Short-term Investments

-500

0

-500

0

0

'

-500

0

-500

0

-500

0

'

Transfer to restricted cash and cash equivalents

'

'

12.4

-24.1

'

'

'

'

-11.2

-13.2

'

'

'

Net cash used for investing activities

'

'

'

'

'

'

'

'

-579.8

-76.6

'

'

'

Financing activities

'

'

'

'

'

'

'

'

'

'

'

'

'

Net repayments under credit arrangements

'

'

-3

24.6

'

'

'

'

-0.3

-0.4

'

'

'

Proceeds from exercise of stock options

'

'

30.9

25.7

'

'

'

'

31.7

25.7

'

'

'

Excess tax benefits from stock-based compensation

-33.7

23

'

'

'

'

'

'

'

-33.7

'

'

'

Net cash provided by financing activities

'

'

'

'

'

'

'

'

-2.3

48.3

'

'

'

Net decrease in cash and cash equivalents

'

'

'

'

'

'

'

'

-375.8

115.8

'

'

'

Cash and cash equivalents, beginning of period

'

'

1,336.90

1,048.30

'

'

'

'

1,064.20

788.6

'

'

'

Cash and cash equivalents, end of period

1,054.70

1,251.20

1,054.70

1,251.20

'

'

688.4

904.4

688.4

904.4

688.4

'

'

Current Assets

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and cash equivalents

1,054.70

1,251.20

1,054.70

1,251.20

'

'

688.4

904.4

688.4

904.4

688.4

'

'

Restricted cash and cash equivalents

185.2

'

185.2

'

197.6

'

129.5

'

129.5

'

129.5

118.3

'

Trade accounts receivable, net

467.8

'

467.8

'

474.8

'

140.1

'

140.1

'

140.1

132.6

'

Accounts receivable—unconsolidated affiliate

16.1

'

16.1

'

15.6

'

14.9

'

14.9

'

14.9

14.1

'

Receivables from non-filing entities, net

'

'

'

'

'

'

154.1

'

154.1

'

154.1

160.5

'

Inventories

314.8

'

314.8

'

278.6

'

138.1

'

138.1

'

138.1

106.3

'

Other current assets

140.4

'

140.4

'

78.4

'

15.7

'

15.7

'

15.7

58.5

'

Total Current Assets

2,689.60

'

2,689.60

'

2,440.20

'

1,780.80

'

1,780.80

'

1,780.80

1,654.50

'

Properties and equipment, net

787.8

'

787.8

'

770.5

'

449.5

'

449.5

'

449.5

433.5

'

Deferred income taxes

814.6

'

814.6

'

956.3

'

788

'

788

'

788

935.5

'

Asbestos-related insurance

500

'

500

'

500

'

500

'

500

'

500

500

'

Loans receivable from non-filing entities, net

'

'

'

'

'

'

286.5

'

286.5

'

286.5

282.1

'

Investment in non-filing entities

'

'

'

'

'

'

556.3

'

556.3

'

556.3

449.5

'

Investment in unconsolidated affiliate

90.8

'

90.8

'

85.5

'

90.8

'

90.8

'

90.8

85.5

'

Other assets

36.1

'

36.1

'

24.5

'

58.1

'

58.1

'

58.1

47.2

'

Total Assets

5,230

'

5,230

'

5,090.20

'

4,510

'

4,510

'

4,510

4,387.80

'

Liabilities Not Subject to Compromise

'

'

'

'

'

'

'

'

'

'

'

'

'

Current liabilities (including $15.0 due to unconsolidated affiliate) (2012—$6.0)

640.3

'

640.3

'

646.3

'

209.6

'

209.6

'

209.6

244.7

'

Underfunded defined benefit pension plans

'

'

'

'

'

'

13.4

'

13.4

'

13.4

161

'

Other liabilities (including $24.1 due to unconsolidated affiliate) (2012—$22.4)

45.2

'

45.2

'

45

'

58.7

'

58.7

'

58.7

56.5

'

Total Liabilities Not Subject to Compromise

991.7

'

991.7

'

1,154.80

'

281.7

'

281.7

'

281.7

462.2

'

Liabilities Subject to Compromise

3,626.40

'

3,626.40

'

3,617.10

'

3,626.40

'

3,626.40

'

3,626.40

3,617.10

'

Total Liabilities

4,618.10

'

4,618.10

'

4,771.90

'

3,908.10

'

3,908.10

'

3,908.10

4,079.30

'

Total W. R. Grace & Co. Shareholders' Equity

601.8

'

601.8

'

308.4

'

601.8

'

601.8

'

601.8

308.4

'

Noncontrolling interests in Chapter 11 filing entities

10.1

'

10.1

'

9.9

'

0.1

'

0.1

'

0.1

0.1

'

Total Equity

611.9

402.2

611.9

402.2

318.3

167.5

601.9

'

601.9

'

601.9

308.5

'

Total Liabilities and Equity

5,230

'

5,230

'

5,090.20

'

4,510

'

4,510

'

4,510

4,387.80

'

Interest accrued on pre-petition liabilities subject to compromise

'

'

$28.10

$30

'

'

'

'

$28.10

$30

'

'

'

[1]

(1)As of September 30, 2013, and December 31, 2012, approximately $11.0 million and $10.1 million, respectively, of certain pension and postretirement benefit obligations subject to compromise have been presented in "other current liabilities" in the Consolidated Balance Sheets in accordance with ASC 715 "Compensation—Retirement Benefits".

AsbestosRelated_Litigation_Det

Asbestos-Related Litigation (Details) (USD $)

1 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

3 Months Ended

24 Months Ended

3 Months Ended

4 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Share data in Millions, unless otherwise specified

Mar. 31, 2003

Sep. 30, 2013

Dec. 31, 2012

Dec. 31, 2012

Apr. 02, 2001

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Mar. 31, 2003

Sep. 30, 2013

Apr. 02, 2001

Sep. 30, 2013

Dec. 31, 2001

Dec. 31, 2005

Sep. 30, 2013

Oct. 31, 2008

Sep. 30, 2013

Mar. 31, 2003

Apr. 02, 2001

Sep. 30, 2013

Dec. 31, 2009

claim

claim

lawsuit

Low

High

Threatened Litigation [Member]

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Property Damage Litigation

Personal Damage Trust [Member]

Personal Damage Trust [Member]

Personal Injury Litigation

Canada

Canada

claim

lawsuit

lawsuit

Zonolite Attic Insulation ("ZAI")

Zonolite Attic Insulation ("ZAI")

Zonolite Attic Insulation ("ZAI")

Zonolite Attic Insulation ("ZAI")

Zonolite Attic Insulation ("ZAI")

claim

claim

claim

Personal Damage Trust [Member]

Personal Damage Trust [Member]

claim

lawsuit

lawsuit

Canada

United States (U.S.)

United States (U.S.)

claim

claim

item

lawsuit

item

claim

Asbestos contingencies

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Appeals, Number of Appeals Pending

'

5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of pending lawsuits

'

'

'

'

65,656

'

'

'

'

16

17

8

'

'

'

'

'

'

'

'

'

Number of settled and dismissed claims

'

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

Number of pending claims

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

129,191

'

'

Number of lawsuits filed prior to the filing date

'

'

'

'

'

'

'

'

'

'

380

'

'

'

'

'

'

'

'

'

'

Number of lawsuits related to former asbestos containing products

'

'

'

'

'

'

'

'

'

8

'

2

'

'

'

'

'

'

'

'

'

Bankruptcy Claims, Non Asbestos Related Pending Number

9,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3,300

4,400

'

'

'

Number of bankruptcy claims outstanding

'

'

'

'

'

'

'

'

'

430

'

'

'

'

'

'

'

'

'

'

'

Number of bankruptcy claims settled

'

'

'

'

'

'

'

'

'

410

'

'

'

'

'

'

'

'

'

'

'

Amount of bankruptcy claims settled

'

'

'

'

'

'

'

'

'

$151,700,000

'

'

'

'

'

'

'

'

'

'

'

Number of purported class action lawsuits

'

'

'

'

'

'

'

'

'

'

'

'

8

10

'

'

'

'

'

'

'

Number of bankruptcy claims filed

14,900

'

'

'

'

'

'

'

'

'

'

'

'

'

'

17,960

4,335

'

'

220

14,100

Number of additional bankruptcy claims filed

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,310

'

'

'

'

'

'

Asbestos-Related Liability

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asbestos-related contingencies

'

2,065,000,000

2,065,000,000

2,065,000,000

'

'

'

2,065,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Provision for asbestos-related contingencies

'

'

365,000,000

365,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of warrants issued by entity to fund trust (in shares)

'

10

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Exercise price of warrant (in dollars per share)

'

17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Settlement of warrant at cash value

'

'

'

'

'

375,000,000

490,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred payment obligation per year for five years beginning January 2, 2019

'

110,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred payment obligation per year for ten years beginning January 2, 2024

'

100,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated deferred payment obligation

'

547,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Rights

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount agreed by the insurers, to be paid to the PI trust in respect of claims for which the company was provided coverage under the affected policies

'

396,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum aggregate amount available under settlement agreements

'

487,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Excess coverage amount with no agreements with insurers

'

483,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum estimated eligible claims to access total coverage

'

4,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Remaining excess coverage available from solvent insurers

'

970,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amount to fund the PI and PD Trusts

'

528,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Asbestos Related Insurance

'

$500,000,000

$500,000,000

$500,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Bankruptcy Appeals, Number of favorvable rulings

'

4

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Inventories_Details

Inventories (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Raw materials	$78.90	$66.50
In process	52.9	46.1
Finished products	151.6	133.8
Other	31.4	32.2
Total inventories	$314.80	$278.60

Debt_Details

Debt (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt Disclosure [Abstract]	'	'
Debt payable within one year	$86.20	$83.40
Debt payable after one year	7.4	13.4
Debt Subject to Compromise	'	'
Bank borrowings	500	500
Accrued interest on bank borrowings	460.1	437.2
Drawn letters of credit	26.7	26.5
Accrued interest on drawn letters of credit	10.7	9.6
Debt Subject to Compromise	$997.50	$973.30
Weighted average interest rates on total debt (as a percent)	3.50%	3.50%

Fair_Value_Measurements_and_Ri2

Fair Value Measurements and Risk (Details)

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

In Millions, unless otherwise specified

country

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Recurring basis

Fixed-rate natural gas swaps

Fixed-rate aluminum swaps

Currency forward contracts

Total

Total

Fair Value, Inputs, Level 1 [Member]

Fair Value, Inputs, Level 1 [Member]

Significant Other Observable Inputs (Level 2)

Significant Other Observable Inputs (Level 2)

Fair Value, Inputs, Level 3 [Member]

Fair Value, Inputs, Level 3 [Member]

USD ($)

USD ($)

EUR (€)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

MMBTU

lb

Items measured at Fair Value on a Recurring Basis

'

'

'

'

'

'

'

'

'

'

'

'

Maximum period of cash flow hedging

'

'

'

'

'

'

'

'

'

'12 months

'12 months

'

Nonmonetary Notional Amount of Price Risk Cash Flow Hedge Derivatives, Number of Units

'

'

'

'

'

'

'

'

'

800,000

1,700,000

'

Total contract value

'

'

'

'

'

'

'

'

'

$3.50

$1.60

'

Number of countries where company does business, greater than

40

'

'

'

'

'

'

'

'

'

'

'

Total notional amount related to the remaining outstanding currency forward contracts

'

'

'

'

'

'

'

'

'

'

'

194.5

Assets

'

'

'

'

'

'

'

'

'

'

'

'

Currency derivatives, assets

'

2.2

1.2

0

0

2.2

1.2

0

0

'

'

'

Commodity derivatives, assets

'

0

0.2

0

0

0

0.2

0

0

'

'

'

Total Assets

'

2.2

1.4

0

0

2.2

1.4

0

0

'

'

'

Liabilities

'

'

'

'

'

'

'

'

'

'

'

'

Currency derivatives, liabilities

'

10.8

5.1

0

0

10.8

5.1

0

0

'

'

'

Commodity derivatives, liabilities

'

0.5

0.4

0

0

0.5

0.4

0

0

'

'

'

Total Liabilities

'

$11.30

$5.50

$0

$0

$11.30

$5.50

$0

$0

'

'

'

Fair_Value_Measurements_and_Ri3

Fair Value Measurements and Risk (Details 2) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair values of derivative instruments	'	'
Asset Derivatives	$2.20	$1.40
Liability Derivatives	11.3	5.5
Derivatives designated as hedging instruments under ASC 815 | Other current assets	'	'
Fair values of derivative instruments	'	'
Asset Derivatives, Commodity contracts	0	0.2
Asset Derivatives, Currency contracts	0.7	1.2
Derivatives designated as hedging instruments under ASC 815 | Other current liabilities	'	'
Fair values of derivative instruments	'	'
Liability Derivatives, Commodity contracts	0.5	0.4
Liability Derivatives, Currency contracts	0.1	0.2
Derivatives designated as hedging instruments under ASC 815 | Other Assets [Member]	'	'
Fair values of derivative instruments	'	'
Asset Derivatives, Currency contracts	1.4	'
Derivatives designated as hedging instruments under ASC 815 | Other Liabilities [Member]	'	'
Fair values of derivative instruments	'	'
Liability Derivatives, Currency contracts	0	'
Derivatives not designated as hedging instruments under ASC 815 | Other current assets	'	'
Fair values of derivative instruments	'	'
Asset Derivatives, Currency contracts	0.1	0
Derivatives not designated as hedging instruments under ASC 815 | Other current liabilities	'	'
Fair values of derivative instruments	'	'
Liability Derivatives, Currency contracts	$10.70	$4.90

Fair_Value_Measurements_and_Ri4

Fair Value Measurements and Risk (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivatives in ASC 815 cash flow hedging relationships	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	$0.20	$1.60	$0.40	($0.70)
Gain (loss) from hedging activities	0.1	-0.7	1	-5.3
Derivatives in ASC 815 cash flow hedging relationships | Cost of goods sold	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	'	0.8	'	0.8
Derivatives in ASC 815 cash flow hedging relationships | Currency contracts | Cost of goods sold	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	0	'	-0.2	'
Gain (loss) from hedging activities	-0.1	0.6	-0.2	0.4
Derivatives in ASC 815 cash flow hedging relationships | Currency contracts | Other income (expense)	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	0.3	'	1	'
Gain (loss) from hedging activities	0.5	'	1.3	'
Derivatives in ASC 815 cash flow hedging relationships | Commodity contracts | Cost of goods sold	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	-0.1	0.8	-0.4	-1.5
Gain (loss) from hedging activities	-0.3	-1.3	-0.1	-5.7
Not Designated as Hedging Instrument [Member] | Currency contracts | Other income (expense)	'	'	'	'
Gains and losses on derivative instruments	'	'	'	'
Amount of Gain or (Loss) Recognized in Income on Derivative	($9.90)	($4.40)	($5.80)	$3.40

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Estimated income tax rate for forecasted income (as a percent)	33.90%	'	'	-64.60%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	'	'	35.00%	'
Material change to aggregate recorded liabilities for uncertain tax positions in the next twelve months	'	'	'	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Other Information	'	'	'12 months	'
Liability For Asbestos Warrant Settlement Amount1	'	$365	'	$365
Accrued interest and penalties related to uncertain tax positions	3.9	8.3	3.9	8.3
Accrued interest and penalties related to uncertain tax positions, Net of applicable tax benefits	3.1	5.5	3.1	5.5
Non-US tax positions open to examination	'	'	'	'
Material change to aggregate recorded liabilities for uncertain tax positions in the next twelve months	'	'	'	'
Material changes to uncertain tax positions, upper range	91	'	91	'
Expected recognition of a deferred charge	1	'	1	'
Examination issues and settlements with U.S. federal, state, and foreign tax authorities	'	'	'	'
Material change to aggregate recorded liabilities for uncertain tax positions in the next twelve months	'	'	'	'
Decrease in unrecognized tax benefits during the next 12 months	$78	'	$78	'

Pension_Plans_and_Other_Postre2

Pension Plans and Other Postretirement Benefit Plans (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Overfunded defined benefit pension plans	$30.20	$33.80
Total underfunded and unfunded defined benefit pension plans	-250.8	-400.6
Unfunded defined benefit pension plans included in liabilities subject to compromise	-174.8	-188.1
Pension liabilities included in other current liabilities	-386.7	'
Defined benefit pension plans, projected obligation	'	1,955
Defined Benefit Plan, Fair Value of Plan Assets, Period Increase (Decrease)	6	'
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	159	'
Pension Plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Unfunded defined benefit pension plans included in liabilities subject to compromise	-121.6	-128.5
Pension liabilities included in other current liabilities	-14.3	-14
Net funded status	-356.5	-509.3
Non-U.S. pension plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Percentage of defined benefit plan obligation represented by specified group of countries	'	90.00%
Postretirement Benefits Other Than Pensions	'	'
Ultimate health care cost rate (as a percent)	5.00%	'
Non-U.S. pension plans | Canada	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Defined benefit pension plans, discount rate (as a percent)	4.75%	4.50%
Non-U.S. pension plans | UNITED KINGDOM	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Defined benefit pension plans, discount rate (as a percent)	'	-4.25%
Non-U.S. pension plans | GERMANY	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Defined benefit pension plans, discount rate (as a percent)	3.75%	3.50%
Postretirement Benefits Other Than Pensions	'	'
Postretirement Benefits Other Than Pensions	'	'
Minimum eligible age for medical plan benefits	'55 years	'
Minimum eligible tenure of service for medical plan benefits	'10 years	'
Minimum required contribution by retirees and beneficiaries, as percentage of the calculated premium	40.00%	'
Percentage contribution by retirees for any increase in premium costs	100.00%	'
Initially assumed increase in per capita costs (as a percent)	8.25%	'
Maximum impact of one percentage point increase (decrease) in assumed health care medical cost trend rate on postretirement benefit obligations	1	'
Overfunded pension plans | Pension Plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Overfunded defined benefit pension plans	30.2	33.8
Overfunded pension plans | Non-U.S. pension plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Defined benefit pension plans, discount rate (as a percent)	'	4.06%
Underfunded and Unfunded pension plans | Pension Plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Total underfunded and unfunded defined benefit pension plans	-250.8	-400.6
Underfunded pension plans | Pension Plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Total underfunded and unfunded defined benefit pension plans	-30.2	-179.7
Underfunded pension plans | U.S. qualified pension plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Defined benefit pension plans, discount rate (as a percent)	4.75%	3.75%
Unfunded pension plans | Pension Plans	'	'
Funded status of fully funded, underfunded, and unfunded pension plans:	'	'
Total underfunded and unfunded defined benefit pension plans	($220.60)	($220.90)

Pension_Plans_and_Other_Postre3

Pension Plans and Other Postretirement Benefit Plans (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Periodic Benefit Cost	'	'	'	'
Amortization of prior service cost	'	$0	'	$0
Defined contribution retirement plan	'	'	'	'
Percentage that the employer contributes of employee contributions under 401(k) plan	100.00%	'	'	'
Maximum percentage of employee compensation match by employer to defined contribution plan	6.00%	'	'	'
Costs related to defined contribution retirement plan	3.2	3.3	9.9	9.9
U.S. qualified pension plans	'	'	'	'
Net Periodic Benefit Cost	'	'	'	'
Service cost	6.3	5.4	18.9	16.1
Interest cost	12.9	14	38.9	42
Expected return on plan assets	-17	-15.8	-51	-47.4
Amortization of prior service cost	0.2	0.2	0.6	0.6
Amortization of net deferred actuarial loss	9.5	8.9	28.5	26.7
Net periodic benefit cost	11.9	12.7	35.9	38
Defined benefit plan, employer accelerated contribution approved by Bankruptcy Court	50	'	50	'
Non-U.S. pension plans	'	'	'	'
Net Periodic Benefit Cost	'	'	'	'
Service cost	2.8	2.2	8.2	6.7
Interest cost	5.1	5.3	15.3	16.1
Expected return on plan assets	-3.4	-3.7	-10.4	-11.1
Amortization of prior service cost	0	'	0	'
Amortization of net deferred actuarial loss	1.8	1.1	5.9	3.5
Net periodic benefit cost	6.3	4.9	19	15.2
Postretirement Benefits Other Than Pensions	'	'	'	'
Net Periodic Benefit Cost	'	'	'	'
Service cost	0	0	0.1	0.1
Interest cost	0.5	0.6	1.6	1.9
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	0	0	0	0
Amortization of net deferred actuarial loss	0.2	0.2	0.4	0.5
Net periodic benefit cost	$0.70	$0.80	$2.10	$2.50

Other_Balance_Sheet_Accounts_D

Other Balance Sheet Accounts (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other Current Liabilities	'	'
Accrued compensation	$74.20	$84.50
Income tax payable	29	44.8
Customer volume rebates	33.5	32.5
Pension liabilities	14.3	14
Accrued Chapter 11 reorganization expenses	6.4	6.6
Accrued commissions	6.4	12.9
Restructuring liability	5.2	3
Fair value of currency forward and commodity contracts	11.3	5.5
Deferred tax liability	0.6	0.6
Other accrued liabilities	108.4	102.9
Total Other Current Liabilities	$289.30	$307.30

Commitments_and_Contingent_Lia1

Commitments and Contingent Liabilities (Details) (USD $)	3 Months Ended	9 Months Ended			12 Months Ended					3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2010	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
	site				Vermiculite Related Matters	Vermiculite Related Matters	Vermiculite Related Matters	Non-Vermiculite Related Matters	Non-Vermiculite Related Matters	Multi-Site Settlement
					facility	facility				site
										claim
Environmental remediation	'	'	'	'	'	'	'	'	'	'
Estimated liability for environmental investigative and remediation costs	$134.20	$134.20	'	$141.50	$60.80	'	$58.30	$75.90	$80.70	'
Net cash expenditures	'	11.2	8.1	'	'	'	'	'	'	'
Maximum number of operating plants under U.S. Environmental Protection Agency (EPA) reinvestigation	'	'	'	'	'	105	'	'	'	'
Number of facilities expanded	'	'	'	'	8	'	'	'	'	'
Number of sites for potential contamination claims under U.S. Environmental Protection Agency (EPA) investigation	'	'	'	'	'	'	'	'	'	38
Amount agreed to pay in settlement of outstanding claims	'	'	'	'	'	'	'	'	'	$44
Number of outstanding claims settled	'	'	'	'	'	'	'	'	'	35
Number of remaining sites for remediation	2	'	'	'	'	'	'	'	'	'

Commitments_and_Contingent_Lia2

Commitments and Contingent Liabilities (Details 2) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Financial Guarantee	'
Financial assurances	'
Gross financial assurances issued and outstanding	$261.70
Surety Bonds	'
Financial assurances	'
Gross financial assurances issued and outstanding	108.5
Standby Letters of Credit	'
Financial assurances	'
Gross financial assurances issued and outstanding	153.2
Letters of Credit	'
Financial assurances	'
Gross financial assurances issued and outstanding	$83.80

Restructuring_Expenses_and_Rel2

Restructuring Expenses and Related Asset Impairments (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring expenses and related asset impairments	'	'	'	'
Severance and other employee related costs	$1.50	$0.50	$5.70	$5.40
Asset impairments and other restructuring costs	2.1	0.6	3	1
Total restructuring expenses and related asset impairments	3.6	1.1	8.7	6.4
Restructuring Liability	'	'	'	'
Balance at beginning of the period	'	'	3	'
Accruals for severance and other employee related costs	'	'	6	'
Payments	'	'	-3.8	-7.2
Balance at end of the period	5.2	'	5.2	'
Grace Catalysts Technologies [Member]	'	'	'	'
Restructuring expenses and related asset impairments	'	'	'	'
Total restructuring expenses and related asset impairments	2	'	'	'
Grace Materials Technologies [Member]	'	'	'	'
Restructuring expenses and related asset impairments	'	'	'	'
Total restructuring expenses and related asset impairments	0.4	'	'	'
Grace Construction Products	'	'	'	'
Restructuring expenses and related asset impairments	'	'	'	'
Total restructuring expenses and related asset impairments	$1.20	'	'	'

Other_Income_Expense_net_Detai

Other (Income) Expense, net (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Income and Expenses [Abstract]	'	'	'	'
Translation effects-intercompany loans	($10.10)	($5.20)	($6.60)	$2.30
Value of currency forward contracts-intercompany loans	9.9	4.7	5.7	-4
Currency transaction loss in Venezuela	'	'	8.5	'
Other currency transaction effects	1.5	-0.1	3	0.5
Interest income of non-Debtor Subsidiaries	-0.2	-0.3	-0.5	-0.7
Net (gain) loss on sales of investments and disposals of assets	1.1	0	0	0.3
Other miscellaneous income	-1.5	-2.3	-5	-4.4
Total other (income) expense, net	$0.70	($3.20)	$5.10	($6)

Other_Comprehensive_Income_Det

Other Comprehensive Income (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Defined benefit pension and other postretirement plans, Pre-Tax Amount	'	'	'	'
Amortization of net prior service cost included in net periodic benefit cost, Pre-Tax Amount	$0.20	$0.20	$0.60	$0.60
Amortization of net deferred actuarial loss included in net periodic benefit cost, Pre-Tax Amount	11.5	10.2	34.8	30.7
Other Comprehensive Income, Defined Benefit Plan, Other Changes in Funded Status Recognized in Net Periodic Benefit Cost, before Tax	33.5	-28.4	116.6	-88.8
Benefit plans, net, Pre-Tax Amount	45.2	-18	152	-57.5
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax, Portion Attributable to Parent	5	14.5	-18.3	5.1
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent	0.1	2.3	-0.6	4.6
Other comprehensive income attributable to W. R. Grace and Co. shareholders, Pre-Tax Amount	50.3	-1.2	133.1	-47.8
Defined benefit pension and other postretirement plans, Tax Benefit/(Expense)	'	'	'	'
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Tax	-0.2	-0.1	-0.3	-0.2
Other Comprehensive Income, Amortization of Defined Benefit Plan, Net Deferred Actuarial Gain (Loss), Recognized in Net Periodic Benefit Cost Tax Effect	-3.8	-3.5	-11.7	-10.5
Other Comprehensive Income, Defined Benefit Plan, Other Changes in Funded Status Recognized in Net Periodic Benefit Cost Tax Effect	-12.4	8.6	-41.7	27.9
Benefit plans, net, Tax Benefit/(Expense)	-16.4	5	-53.7	17.2
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent	0	0	0	0
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax, Portion Attributable to Parent	-0.1	-0.8	0.2	-1.6
Other comprehensive income attributable to W. R. Grace and Co. shareholders, Tax Benefit/(Expense)	-16.5	4.2	-53.5	15.6
Defined benefit pension and other postretirement plans, After-Tax Amount:	'	'	'	'
Amortization of net prior service credit included in net periodic benefit cost, After-Tax Amount	0	-0.1	0.3	-0.4
Amortization of net deferred actuarial loss included in net periodic benefit cost, After-Tax Amount	7.7	6.7	23.1	20.2
Other changes in funded status, After-Tax Amount	21.1	-19.8	74.9	-60.9
Benefit plans, net, After-Tax Amount	28.8	-13	98.3	-40.3
Currency translation adjustments, After-Tax Amount	5	14.5	-18.3	5.1
Gain (loss) from hedging activities, net of income taxes	0	1.5	-0.4	3
Other comprehensive income attributable to W. R. Grace & Co. shareholders, After-Tax Amount	$33.80	$3	$79.60	($32.20)

Other_Comprehensive_Income_Com

Other Comprehensive Income Comprehensive Income (Details 1) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Increase (Decrease) in Accumulated Other Comprehensive Loss [Roll Forward]	'	'	'	'
Beginning, Defined Benefit Pension and Other Postretirement Plans	'	'	($641.80)	($605.20)
Beginning, Currency Translation Adjustments	'	'	35.6	30.2
Beginning, Gains and Losses from Hedging Activities	'	'	-0.3	-2.7
Beginning, Unrealized Loss on Investment	'	'	-0.8	-0.8
Beginning, Total	'	'	-607.3	-578.5
Other Comprehensive Income, Defined Benefit Plan, Other Changes in Funded Status Recognized in Net Periodic Benefit Cost Net of Tax	21.1	-19.8	74.9	-60.9
Currency translation adjustments, After-Tax Amount	5	14.5	-18.3	5.1
Other comprehensive income (loss) before reclassifications, Gains and Losses from Hedging Activities	'	'	0.4	-0.4
Other comprehensive income (loss) before reclassifications, Total	'	'	57	-56.2
Amounts reclassified from accumulated other comprehensive loss, Defined Benefit Pension and Other Postretirement Plans	7.7	6.8	23.4	20.6
Amounts reclassified from accumulated other comprehensive loss, Gains and Losses from Hedging Activities	-0.1	0.4	-0.8	3.4
Amounts reclassified from accumulated other comprehensive loss, Total	7.6	7.2	22.6	24
Benefit plans, net, After-Tax Amount	28.8	-13	98.3	-40.3
Gain (loss) from hedging activities, net of income taxes	0	1.5	-0.4	3
Other comprehensive income attributable to W. R. Grace & Co. shareholders, After-Tax Amount	33.8	3	79.6	-32.2
Ending, Defined Benefit Pension and Other Postretirement Plans	-543.5	-645.5	-543.5	-645.5
Ending, Currency Translation Adjustments	17.3	35.3	17.3	35.3
Ending, Gains and Losses from Hedging Activities	-0.7	0.3	-0.7	0.3
Ending, Unrealized Loss on Investment	-0.8	-0.8	-0.8	-0.8
Ending, Total	($527.70)	($610.70)	($527.70)	($610.70)

Other_Comprehensive_Income_Det1

Other Comprehensive Income (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
	country		country
Defined benefit pension and other postretirement plans:	'	'	'	'	'
Amortization of net prior service cost	($0.20)	($0.20)	($0.60)	($0.60)	'
Amortization of net deferred actuarial loss	-11.5	-10.2	-34.8	-30.7	'
Total before tax	-11.7	-10.4	-35.4	-31.3	'
Tax (expense) benefit	4	3.6	12	10.7	'
Net of tax	-7.7	-6.8	-23.4	-20.6	'
Gain (loss) from hedging activities	'	'	'	'	'
Total before tax	0.1	-0.7	1	-5.3	'
Tax (expense) benefit	0	0.3	-0.2	1.9	'
Net of tax	0.1	-0.4	0.8	-3.4	'
Amounts reclassified from accumulated other comprehensive loss, Total	-7.6	-7.2	-22.6	-24	'
Net deferred actuarial loss, net of tax	542.5	'	542.5	'	640.5
Net prior service cost, net of tax	1	'	1	'	1.3
Number of countries in which the entity has operations	40	'	40	'	'
Cash Flow Hedging [Member]	'	'	'	'	'
Gain (loss) from hedging activities	'	'	'	'	'
Gain (loss) from hedging activities	0.1	-0.7	1	-5.3	'
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Other Income(Expense) [Member]	'	'	'	'	'
Gain (loss) from hedging activities	'	'	'	'	'
Gain (loss) from hedging activities	0.5	'	1.3	'	'
Cash Flow Hedging [Member] | Foreign Exchange Contract [Member] | Cost of Sales [Member]	'	'	'	'	'
Gain (loss) from hedging activities	'	'	'	'	'
Gain (loss) from hedging activities	-0.1	0.6	-0.2	0.4	'
Cash Flow Hedging [Member] | Commodity Contract [Member] | Cost of Sales [Member]	'	'	'	'	'
Gain (loss) from hedging activities	'	'	'	'	'
Gain (loss) from hedging activities	($0.30)	($1.30)	($0.10)	($5.70)	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.4	0.8	0.3	0.3
Numerators	'	'	'	'
Net income attributable to W. R. Grace and Co. shareholders	$69.40	$75.50	$205.10	$205.70
Denominators	'	'	'	'
Weighted average common shares-basic calculation	76.7	75	76.2	74.7
Dilutive effect of employee stock options (in shares)	1.2	1.4	1.4	1.5
Weighted average common shares-diluted calculation	77.9	76.4	77.6	76.2
Basic earnings per share (in dollars per share)	$0.90	$1.01	$2.69	$2.75
Diluted earnings per share (in dollars per share)	$0.89	$0.99	$2.64	$2.70
Number of warrants not included in diluted earnings per share	10	'	10	'

Operating_Segment_Information_1

Operating Segment Information (Details) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting [Abstract]	'	'	'	'	'
Number of operating segments	3	'	'	'	'
Net Sales	'	'	'	'	'
Net sales	$771.30	'	$776.60	$2,284	$2,357.70
Adjusted EBIT	'	'	'	'	'
Defined benefit pension expense	-18.2	'	-17.6	-54.9	-53.2
Grace Adjusted EBIT	130.7	'	129.1	377.7	384
Reconciliation of operating segment data to financial statements	'	'	'	'	'
Grace Adjusted EBIT	130.7	'	129.1	377.7	384
Costs related to Chapter 11	-3.9	'	-3.7	-11	-11.1
Asbestos-related costs	-2.5	'	-2	-6.7	-25
Restructuring expenses and related asset impairments	-3.6	'	-1.1	-8.7	-6.4
Certain costs related to divested businesses	-1	'	-0.2	1	-0.4
Interest expense and related financing costs	-10.7	'	-11.5	-32.1	-34.1
Currency transaction loss on cash in Venezuela	'	'	'	-8.5	'
Interest income of non-Debtor subsidiaries	0.2	'	0.3	0.5	0.7
Noncontrolling interests in net income	0.3	'	0.5	1.1	1.3
Income before income taxes	109.5	'	111.4	312.9	309
Grace Catalysts Technologies [Member]	'	'	'	'	'
Net Sales	'	'	'	'	'
Net sales	273.7	'	298.9	831.1	939.7
Adjusted EBIT	'	'	'	'	'
Segment operating income	77.4	'	92	248.4	291.2
Reconciliation of operating segment data to financial statements	'	'	'	'	'
Restructuring expenses and related asset impairments	-2	'	'	'	'
Grace Materials Technologies [Member]	'	'	'	'	'
Net Sales	'	'	'	'	'
Net sales	220.1	'	214.4	663.7	652.6
Adjusted EBIT	'	'	'	'	'
Segment operating income	46.8	'	39.8	135.9	122.3
Reconciliation of operating segment data to financial statements	'	'	'	'	'
Restructuring expenses and related asset impairments	-0.4	'	'	'	'
Construction Products	'	'	'	'	'
Net Sales	'	'	'	'	'
Net sales	277.5	'	263.3	789.2	765.4
Adjusted EBIT	'	'	'	'	'
Segment operating income	45.6	'	36.7	113.7	92.7
Reconciliation of operating segment data to financial statements	'	'	'	'	'
Restructuring expenses and related asset impairments	-1.2	'	'	'	'
Corporate Costs	'	'	'	'	'
Adjusted EBIT	'	'	'	'	'
Segment operating income	-20.9	'	-21.8	-65.4	-69
Reconciliation of operating segment data to financial statements	'	'	'	'	'
Currency transaction loss on cash in Venezuela	'	($6.90)	'	($6.90)	'

Operating_Segment_Information_2

Operating Segment Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Geographic Area Data	'	'	'	'
Net sales	$771.30	$776.60	$2,284	$2,357.70
Total North America	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	248.1	245.8	722.7	731.7
United States (U.S.)	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	227.6	222.6	668.7	663.7
Canada and Puerto Rico	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	20.5	23.2	54	68
Europe Middle East Africa	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	273.7	276.9	816.2	879.8
Asia Pacific	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	155	160.4	478.7	490.1
Latin America	'	'	'	'
Geographic Area Data	'	'	'	'
Net sales	$94.50	$93.50	$266.40	$256.10

Unconsolidated_Affiliate_Detai

Unconsolidated Affiliate (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Investment in unconsolidated affiliates	'	'	'	'	'
Equity method investment, ownership interest (as a percent)	50.00%	'	50.00%	'	'
Investment in unconsolidated affiliate	$90,800,000	'	$90,800,000	'	$85,500,000
Equity in earnings of unconsolidated affiliate	2,800,000	4,900,000	17,100,000	13,800,000	'
Grace sales of catalysts to ART	69,200,000	53,400,000	174,200,000	153,100,000	'
Charges for fixed costs, research and development and selling, general and administrative services to ART	7,000,000	7,200,000	22,500,000	22,300,000	'
Commitment fee on credit facility (as a percent)	'	'	0.10%	'	'
W.R. Grace & Co	'	'	'	'	'
Investment in unconsolidated affiliates	'	'	'	'	'
Line of credit facility, maximum provided by Grace and Chevron each	15,000,000	'	15,000,000	'	'
Chevron	'	'	'	'	'
Investment in unconsolidated affiliates	'	'	'	'	'
Line of credit facility, maximum provided by Grace and Chevron each	$15,000,000	'	$15,000,000	'	'

Noncontrolling_Interests_in_Co2

Noncontrolling Interests in Consolidated Affiliates (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Summary financial statistics - statement of operations and cash flows, consolidated affiliates	'	'	'	'	'	'
Sales	$771.30	$776.60	$2,284	$2,357.70	'	'
Income before taxes	109.5	111.4	312.9	309	'	'
Net income	69.7	76	206.2	207	'	'
Noncontrolling interests in net income	0.3	0.5	1.1	1.3	'	'
Summary financial statistics - balance sheet information, consolidated affiliates	'	'	'	'	'	'
Other current assets	140.4	'	140.4	'	78.4	'
Total assets	5,230	'	5,230	'	5,090.20	'
Total liabilities	4,618.10	'	4,618.10	'	4,771.90	'
Shareholders' equity	611.9	402.2	611.9	402.2	318.3	167.5
Noncontrolling interests in shareholders' equity	10.1	'	10.1	'	9.9	'
Joint ventures	'	'	'	'	'	'
Summary financial statistics - statement of operations and cash flows, consolidated affiliates	'	'	'	'	'	'
Sales	24.1	25.3	78	77	'	'
Income before taxes	4.8	1.8	5.8	5.9	'	'
Net income	3.6	1.5	4.8	5	'	'
Noncontrolling interests in net income	0.3	0.5	1.1	1.3	'	'
Summary financial statistics - balance sheet information, consolidated affiliates	'	'	'	'	'	'
Cash	10.6	'	10.6	'	5.7	'
Other current assets	35.8	'	35.8	'	41.6	'
Total assets	78.6	'	78.6	'	73.8	'
Total liabilities	53	'	53	'	47.2	'
Shareholders' equity	$25.60	'	$25.60	'	$26.60	'

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Subsequent Event [Line Items]	'
Business Acquisition, Cost of Acquired Entity, Cash Paid	$500