Griffon (GFF) 10-K 19 Nov 18 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2018	Oct. 31, 2018	Mar. 31, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	GRIFFON CORP
Document Type	10-K
Current Fiscal Year End Date	--09-30
Entity Common Stock, Shares Outstanding		45,674,821
Entity Public Float			$ 656,000,000
Amendment Flag	false
Entity Central Index Key	50,725
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
CURRENT ASSETS
Cash and equivalents	$ 69,758	$ 47,681
Accounts receivable, net of allowances of $6,408 and $5,966	280,509	208,229
Contract costs and recognized income not yet billed, net of progress payments of $3,172 and $4,407	121,803	131,662
Inventories	398,359	299,437
Prepaid and other current assets	42,121	40,067
Assets of discontinued operations held for sale	0	370,724
Assets of discontinued operations not held for sale	324	329
Total Current Assets	912,874	1,098,129
PROPERTY, PLANT AND EQUIPMENT, net	342,492	232,135
GOODWILL	439,395	319,139
INTANGIBLE ASSETS, net	370,858	205,127
OTHER ASSETS	16,355	16,051
ASSETS OF DISCONTINUED OPERATIONS	2,916	2,960
Total Assets	2,084,890	1,873,541
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	13,011	11,078
Accounts payable	233,658	183,951
Accrued liabilities	139,192	83,258
Liabilities of discontinued operations held for sale	0	84,450
Liabilities of discontinued operations	7,210	8,342
Total Current Liabilities	393,071	371,079
LONG-TERM DEBT, net	1,108,071	968,080
OTHER LIABILITIES	106,710	132,537
LIABILITIES OF DISCONTINUED OPERATIONS	2,647	3,037
Total Liabilities	1,610,499	1,474,733
COMMITMENTS AND CONTINGENCIES - See Note 13
SHAREHOLDERS’ EQUITY
Preferred stock, par value $0.25 per share, authorized 3,000 shares, no shares issued	0	0
Common stock, par value $0.25 per share, authorized 85,000 shares, issued shares of 81,520 and 80,663, respectively.	20,380	20,166
Capital in excess of par value	503,396	487,077
Retained earnings	550,523	480,347
Treasury shares, at cost, 35,846 common shares and 33,557 common shares	(534,830)	(489,225)
Accumulated other comprehensive loss	(34,112)	(60,481)
Deferred compensation	(30,966)	(39,076)
Total Shareholders’ Equity	474,391	398,808
Total Liabilities and Shareholders’ Equity	$ 2,084,890	$ 1,873,541

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Statement of Financial Position [Abstract]
Accounts receivable, net allowances	$ 6,408	$ 5,966
Contract costs, net of progress payments	$ 3,172	$ 4,407
Preferred stock, par value (in Dollars per share)	$ 0.25	$ 0.25
Preferred stock, share authorized (in Shares)	3,000,000	3,000,000
Preferred stock, shares issued (in Shares)	0	0
Common stock, par value (in Dollars per share)	$ 0.25	$ 0.25
Common stock, share authorized (in Shares)	85,000,000	85,000,000
Common stock, shares issued (in Shares)	81,520,000	80,663,000
Treasury shares (in Shares)	33,846,000	33,557,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) shares in Thousands, $ in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2017USD ($)$ / sharesshares	Sep. 30, 2016USD ($)$ / sharesshares
Income Statement [Abstract]
Revenue	$ 1,977,918	$ 1,524,997	$ 1,477,035
Cost of goods and services	1,448,358	1,116,881	1,076,342
Gross profit	529,560	408,116	400,693
Selling, general and administrative expenses	433,110	339,089	318,353
Income from continuing operations	96,450	69,027	82,340
Other income (expense)
Interest expense	(65,568)	(51,513)	(49,943)
Interest income	1,697	64	66
Other, net	1,231	(880)	(250)
Total other income (expense)	(62,640)	(52,329)	(50,127)
Income before taxes from continuing operations	33,810	16,698	32,213
Provision (benefit) for income taxes	555	(1,085)	12,432
Income (loss) from continuing operations	33,255	17,783	19,781
Discontinued operations:
Income from operations of discontinued businesses	119,981	22,276	20,952
Provision for income taxes	27,558	25,147	10,723
Income (loss) from discontinued operations	92,423	(2,871)	10,229
Net income	$ 125,678	$ 14,912	$ 30,010
Income from continuing operations (in usd per share) | $ / shares	$ 0.81	$ 0.43	$ 0.48
Income from discontinued operations (in usd per share) | $ / shares	2.25	(0.07)	0.25
Basic earnings per common share (in Dollars per share) | $ / shares	$ 3.06	$ 0.36	$ 0.73
Weighted-average shares outstanding (in Shares) | shares	41,005	41,005	41,074
Income from continuing operations (in usd per share) | $ / shares	$ 0.78	$ 0.41	$ 0.45
Income from discontinued operations (in usd per share) | $ / shares	2.18	(0.07)	0.23
Diluted earnings per common share (in usd per share) | $ / shares	$ 2.96	$ 0.35	$ 0.68
Weighted-average shares outstanding (in Shares) | shares	42,422	43,011	44,109
Other comprehensive income (loss), net of taxes:
Foreign currency translation adjustments	$ 9,403	$ 10,667	$ 17,284
Pension and other post retirement plans	16,381	9,203	(5,651)
Gain (loss) on cash flow hedge	585	890	(1,686)
Total other comprehensive income, net of taxes	26,369	20,760	9,947
Comprehensive income	$ 152,047	$ 35,672	$ 39,957

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 125,678	$ 14,912	$ 30,010
Net (income) loss from discontinued operations	(92,423)	2,871	(10,229)
Adjustments to reconcile net income to net cash provided by operating activities of continuing operations:
Depreciation and amortization	55,803	47,878	46,342
Stock-based compensation	10,078	8,090	10,136
Provision for losses on accounts receivable	96	271	351
Amortization of deferred financing costs and debt discounts	5,219	4,511	7,321
Deferred income tax	(17,633)	2,341	6,044
Gain (loss) on sale/disposal of assets and investments	290	(126)	(319)
Change in assets and liabilities, net of assets and liabilities acquired:
(Increase) decrease in accounts receivable and contract costs and recognized income not yet billed	2,681	(19,131)	(35,933)
(Increase) decrease in inventories	(52,122)	(29,299)	16,103
(Increase) decrease in prepaid and other assets	5,969	(4,781)	1,462
Increase in accounts payable, accrued liabilities and income taxes payable	11,078	17,541	4,829
Other changes, net	11,732	4,073	4,001
Net cash provided by operating activities - continuing operations	66,446	49,151	80,118
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(50,138)	(34,937)	(59,276)
Acquired business, net of cash acquired	(430,932)	(34,719)	(4,470)
Investment sales (purchases)	0	(1,824)	715
Proceeds from Divestiture of Businesses	474,727	0	0
Proceeds from sale of property, plant and equipment	663	143	770
Net cash used in investing activities - continuing operations	(5,680)	(71,337)	(62,261)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0	0	0
Dividends paid	(49,797)	(10,325)	(8,798)
Purchase of shares for treasury	(45,605)	(15,841)	(65,307)
Proceeds from long-term debt	443,058	233,443	302,362
Payments of long-term debt	(300,993)	(170,454)	(208,514)
Change in short-term borrowings	144	0	0
Share premium payment on settled debt	0	(24,997)	0
Financing costs	(7,793)	(1,548)	(4,384)
Purchase of ESOP shares	0	(10,908)	0
Other, net	51	(70)	55
Net cash provided by (used) in financing activities - continuing operations	39,065	(700)	15,414
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash provided by (used in) operating activities	(45,624)	47,193	24,264
Net cash used in investing activities	(10,762)	(45,075)	(31,343)
Net cash provided by (used in) financing activities	(22,541)	(4,268)	(6,526)
Net cash provided by (used in) discontinued operations	(78,927)	(2,150)	(13,605)
Effect of exchange rate changes on cash and equivalents	1,173	164	886
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	22,077	(24,872)	20,552
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	47,681	72,553	52,001
CASH AND EQUIVALENTS AT END OF PERIOD	69,758	47,681	72,553
Supplemental Disclosure of Cash Flow Information:
Cash paid for interest	59,793	48,137	43,208
Cash paid for taxes	$ 32,140	$ 20,998	$ 3,431

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Deferred Compensation [Member]
Balance (in Shares) at Sep. 30, 2015		79,080,000			30,737,000
Balance at Sep. 30, 2015	$ 430,525	$ 19,770	$ 518,485	$ 454,548	$ (436,559)	$ (91,188)	$ (34,531)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	30,010			30,010
Payments of Ordinary Dividends, Common Stock	8,798			(8,798)
Dividends	(8,798)
Amortization of deferred compensation	2,853						2,853
Common stock issued (in Shares)		41,000
Common stock issued		$ 10	(10)
Common stock acquired (in Shares)					4,060,000
Common stock acquired	(65,307)				$ (65,307)
Equity awards granted, net (in Shares)		845,000
Equity awards granted, net	264	$ 212	52
ESOP allocation of common stock	1,317		1,317
Stock-based compensation	10,136		10,136
Other comprehensive income, net of tax	9,947					9,947
Balance (in Shares) at Sep. 30, 2016		79,966,000			34,797,000
Balance at Sep. 30, 2016	410,947	$ 19,992	529,980	475,760	$ (501,866)	(81,241)	(31,678)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,912			14,912
Payments of Ordinary Dividends, Common Stock	10,325
Dividends	(10,325)			(10,325)
Tax effect from exercise/vesting of equity awards, net	(13,738)		(97)		$ (13,641)
Tax effect from exercise/vesting of equity awards, net (in shares)					586,000
Amortization of deferred compensation	3,510						3,510
Common stock issued (in Shares)		3,000
Common stock issued	22		22
Common stock acquired (in Shares)					129,000
Common stock acquired	(2,201)				$ (2,201)
Equity awards granted, net (in Shares)		694,000
Equity awards granted, net		$ 174	(174)
Premium on settlement of convertible debt	(73,855)		(73,855)
Issuance of treasury stock in settlement of convertible debt	48,858		20,375		$ 28,483
Issuance of treasury stock in settlement of convertible debt (in shares)					(1,955,000)
ESOP purchase of common stock	(10,908)						(10,908)
ESOP allocation of common stock	2,736		2,736
Stock-based compensation	8,090		8,090
Other comprehensive income, net of tax	20,760					20,760
Balance (in Shares) at Sep. 30, 2017		80,663,000			33,557,000
Balance at Sep. 30, 2017	398,808	$ 20,166	487,077	480,347	$ (489,225)	(60,481)	(39,076)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125,678			125,678
Payments of Ordinary Dividends, Common Stock	49,797
Dividends	$ (55,502)			(55,502)
Tax effect from exercise/vesting of equity awards, net (in shares)	2,088,739
Shares paid for tax withholding for share based compensation (in Shares)	199,978				200,000
Shares withheld on employee taxes on vested equity awards	$ (4,495)				$ (4,495)
Amortization of deferred compensation	8,110						8,110
Common stock acquired (in Shares)					2,089,000
Common stock acquired	(41,110)				$ (41,110)
Equity awards granted, net (in Shares)		857,000
Equity awards granted, net		$ 214	(214)
ESOP allocation of common stock	4,756		4,756
Stock-based compensation	10,078		10,078
Stock-based consideration	1,699		1,699
Other comprehensive income, net of tax	26,369					26,369
Balance (in Shares) at Sep. 30, 2018		81,520,000			35,846,000
Balance at Sep. 30, 2018	$ 474,391	$ 20,380	$ 503,396	$ 550,523	$ (534,830)	$ (34,112)	$ (30,966)

DESCRIPTION OF BUSINESS AND SUM

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Description of business Griffon Corporation (the “Company” or “Griffon”) is a diversified management and holding company that conducts business through wholly-owned subsidiaries. Griffon oversees the operations of its subsidiaries, allocates resources among them and manages their capital structures. Griffon provides direction and assistance to its subsidiaries in connection with acquisition and growth opportunities as well as in connection with divestitures. In order to further diversify, Griffon also seeks out, evaluates and, when appropriate, will acquire additional businesses that offer potentially attractive returns on capital. Headquartered in New York, N.Y., the Company was founded in 1959 and is incorporated in Delaware. Griffon is listed on the New York Stock Exchange and trades under the symbol GFF. On June 4, 2018, Clopay Building Products Company, Inc. ("CBP") acquired CornellCookson, Inc. ("CornellCookson"), a leading US manufacturer and marketer of rolling steel door and grille products designed for commercial, industrial, institutional and retail use. The accounts, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, and results of operations of CornellCookson, are included in the Company’s consolidated financial statements from the date of acquisition of June 4, 2018. See Note 2, Acquisitions. On November 16, 2017, Griffon announced it entered into a definitive agreement to sell Clopay Plastic Products Company, Inc. ("PPC") and on February 6, 2018, completed the sale to Berry Global, Inc. ("Berry") for approximately $475,000 . As a result, Griffon classified the results of operations of the PPC business as discontinued operations in the Consolidated Statements of Operations for all periods presented and classified the related assets and liabilities associated with the discontinued operations in the consolidated balance sheets. All results and information presented exclude PPC unless otherwise noted. See Note 6, Discontinued Operations. On October 2, 2017, Griffon acquired ClosetMaid LLC ("ClosetMaid"). ClosetMaid, founded in 1965, is a leading North American manufacturer and marketer of wood and wire closet organization, general living storage and wire garage storage products and sells to some of the largest home center retail chains, mass merchandisers, and direct-to-builder professional installers in North America. The accounts, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, and results of operations of ClosetMaid are included in the Company’s consolidated financial statements from the date of acquisition of October 2, 2017. See Note 2, Acquisitions. Griffon currently conducts its operations through two reportable segments: • Home & Building Products (“HBP”) segment consists of two companies, The AMES Companies, Inc. (“AMES”) and CBP: AMES, founded in 1774, is the leading U.S. manufacturer and a global provider of branded consumer and professional tools, landscaping products, and outdoor lifestyle solutions. In 2018, we acquired ClosetMaid, a leader in wood and wire closet organization, general living storage and wire garage storage products for homeowners and professionals. CBP, since 1964, is a leading manufacturer and marketer of residential and commercial garage doors and sells to professional dealers and some of the largest home center retail chains in North America. In 2018, we acquired CornellCookson, a leading U.S. manufacturer and marketer of rolling steel door and grille products designed for commercial, industrial, institutional, and retail use. • Defense Electronics segment consists of Telephonics Corporation ("Telephonics"), founded in 1933, a globally recognized leading provider of highly sophisticated intelligence, surveillance and communications solutions for defense, aerospace and commercial customers. Consolidation The consolidated financial statements include the accounts of Griffon and all subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation. The results of operations of acquired businesses are included from the dates of acquisitions. Earnings per share Due to rounding, the sum of earnings per share may not equal earnings per share of Net income. Discontinued operations Installation Services In 2008, as a result of the downturn in the residential housing market, Griffon exited substantially all operating activities of its Installation Services segment which sold, installed and serviced garage doors and openers, fireplaces, floor coverings, cabinetry and a range of related building products, primarily for the new residential housing market. Operating results of substantially all of this segment have been reported as discontinued operations in the Consolidated Statements of Operations and Comprehensive Income (Loss) for all periods presented; Installation Services is excluded from segment reporting. During the year ended September 30, 2017, Griffon recorded $5,700 of reserves in discontinued operations related to historical environmental remediation efforts and to increase the reserve for homeowner association claims related to the Clopay Services Corporation discontinued operations in 2008. Clopay Plastic Products Company, Inc. ("PPC") On November 16, 2017, Griffon announced it entered into a definitive agreement to sell PPC and on February 6, 2018, completed the sale to Berry for approximately $475,000 . As a result, Griffon classified the results of operations of the PPC business as discontinued operations in the Consolidated Statements of Operations for all periods presented and classified the related assets and liabilities associated with the discontinued operations in the consolidated balance sheets. All results and information presented exclude PPC unless otherwise noted. See Note 6, Discontinued Operations. Reclassifications Certain amounts in prior years have been reclassified to conform to the current year presentation. Use of estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting periods. These estimates may be adjusted due to changes in economic, industry or customer financial conditions, as well as changes in technology or demand. Significant estimates include allowances for doubtful accounts receivable and returns, net realizable value of inventories, restructuring reserves, valuation of goodwill and intangible assets, percentage of completion method of accounting, pension assumptions, useful lives associated with depreciation and amortization of intangible and fixed assets, warranty reserves, sales incentive accruals, stock based compensation assumptions, income taxes and tax valuation reserves, environmental reserves, legal reserves, insurance reserves, the valuation of assets and liabilities of discontinued operations, acquisition assumptions used and the accompanying disclosures. These estimates are based on management’s best knowledge of current events and actions Griffon may undertake in the future. Actual results may ultimately differ from these estimates. Cash and equivalents Griffon considers all highly liquid investments purchased with an initial maturity of three months or less to be cash equivalents. Cash equivalents primarily consist of overnight commercial paper, highly-rated liquid money market funds backed by U.S. Treasury securities and U.S. Agency securities, as well as insured bank deposits. Griffon had cash in non-U.S. bank accounts of approximately $24,900 and $26,500 at September 30, 2018 and 2017, respectively. Substantially all U.S. cash and equivalents are in excess of FDIC insured limits. Griffon regularly evaluates the financial stability of all institutions and funds that hold its cash and equivalents. Fair value of financial instruments The carrying values of cash and cash equivalents, accounts receivable, accounts and notes payable and revolving credit debt approximate fair value due to either the short-term nature of such instruments or the fact that the interest rate of the revolving credit debt is based upon current market rates. The fair value hierarchy, as outlined in the applicable accounting guidance, establishes a fair value hierarchy that requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the hierarchy is based on the lowest level of input that is significant to the fair value measurement. The accounting guidance establishes three levels of inputs that may be used to measure fair value, as follows: • Level 1 inputs are measured and recorded at fair value based upon quoted prices in active markets for identical assets. • Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of assets or liabilities. • Level 3 inputs are unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The fair value of Griffon’s 2022 senior notes approximated $990,000 , on September 30, 2018 . Fair values were based upon quoted market prices (level 1 inputs). Insurance contracts with a value of $3,032 at September 30, 2018 are measured and recorded at fair value based upon quoted prices in active markets for similar assets (level 2 inputs) and are included in Other current assets on the consolidated balance sheet. Items Measured at Fair Value on a Recurring Basis At September 30, 2018 and 2017, trading securities, measured at fair value based on quoted prices in active markets for similar assets (level 2 inputs), with a fair value of $2,644 ( $2,086 cost basis) and $3,352 ( $1,000 cost basis) were included in Prepaid and other current assets on the Consolidated Balance Sheets. During the year ended September 30, 2018, the Company settled trading securities with proceeds totaling $4,126 and recognized a loss of $1,251 in Other income (expense). During the year ended September 30, 2016, the Company settled trading securities with proceeds totaling $715 and recognized a loss of $13 in Other income (expense). Realized and unrealized gains and losses on trading securities and realized gains and losses on available-for-sale securities are included in Other income in the Consolidated Statements of Operations and Comprehensive Income (Loss). In the normal course of business, Griffon’s operations are exposed to the effect of changes in foreign currency exchange rates. To manage these risks, Griffon may enter into various derivative contracts such as foreign currency exchange contracts, including forwards and options. During 2018 and 2017, Griffon entered into several such contracts in order to lock into a foreign currency rate for planned settlements of trade and inter-company liabilities payable in USD. At September 30, 2018 and 2017, Griffon had $12,000 and $14,500 of Australian dollar contracts at a weighted average rate of $1.38 and $1.28 , respectively, which qualified for hedge accounting. These hedges were all deemed effective as cash flow hedges with gains and losses related to changes in fair value deferred and recorded in Other comprehensive income (loss) and Prepaid and other current assets, or Accrued liabilities, until settlement. Upon settlement, gains and losses were recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) in Cost of goods and services. AOCI included deferred gains of $443 ( $288 , net of tax) and deferred gains of $175 ( $114 , net of tax) at September 30, 2018 and 2017, respectively. Upon settlement, gains (losses) of $657 and $(1,458) were recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) in Cost of goods and services ("COGS") during the years ended September 30, 2018 and September 30, 2017, respectively. All contracts expire in 31 to 92 days . At September 30, 2018 and 2017, Griffon had $700 and $4,690 , respectively, of Canadian dollar contracts at a weighted average rate of $1.29 and $1.25 . These contracts, which protect Canadian operations from currency fluctuations for U.S. dollar based purchases, do not qualify for hedge accounting and fair value losses of $7 and $378 were recorded in Other assets and to Other income for the outstanding contracts, based on similar contract values (level 2 inputs), for the years ended September 30, 2018 and 2017, respectively. Realized gains (losses) of $(161) and $200 , were recorded in Other income during the years ended September 30, 2018 and September 30, 2017, respectively. All contracts expire in 30 to 358 days . Pension plan assets with a fair value of $150,634 at September 30, 2018 , are measured and recorded at fair value based upon quoted prices in active markets for identical assets (level 1 inputs) and quoted market prices for similar assets (level 2 inputs). Non-U.S. currency translation Assets and liabilities of non-U.S. subsidiaries, where the functional currency is not the U.S. dollar, have been translated at year-end exchange rates and profit and loss accounts have been translated using weighted average exchange rates. Adjustments resulting from currency translation have been recorded in the equity section of the balance sheet in AOCI as cumulative translation adjustments. Cumulative translation adjustments were gains of $9,403 and $10,667 for the year ended September 30, 2018 and 2017, respectively. As of September 30, 2018 and 2017, the foreign currency translation components of Accumulated other comprehensive loss were $22,824 and $32,227 , respectively. Assets and liabilities of an entity that are denominated in currencies other than that entity’s functional currency are re-measured into the functional currency using period end exchange rates, or historical rates where applicable to certain balances. Gains and losses arising on remeasurements are recorded within the Consolidated Statement of Operations and Comprehensive Income (Loss) as a component of Other income (expense). Revenue recognition Revenue is recognized when the following circumstances are satisfied: a) persuasive evidence of an arrangement exists, b) delivery has occurred, title has transferred or services are rendered, c) price is fixed and determinable and d) collectability is reasonably assured. Goods are sold on terms that transfer title and risk of loss at a specified location. Revenue recognition from product sales occurs when all factors are met, including transfer of title and risk of loss, which occurs either upon shipment or upon receipt by customers at the location specified in the terms of sale. Other than standard product warranty provisions, sales arrangements provide for no other significant post-shipment obligations. From time to time and for certain customers, rebates and other sales incentives, promotional allowances or discounts are offered, typically related to customer purchase volumes, all of which are fixed or determinable and are classified as a reduction of revenue and recorded at the time of sale. Griffon provides for sales returns allowances based upon historical returns experience. Telephonics earns a substantial portion of its revenue as either a prime or subcontractor from contract awards with the U.S. Government, as well as non-U.S. governments and other commercial customers. These formal contracts are typically long-term in nature, usually greater than one year . Revenue and profits from these long-term fixed price contracts are recognized under the percentage-of-completion method of accounting. Revenue and profits on fixed-price contracts that contain engineering as well as production requirements are recorded based on the ratio of total actual incurred costs to date to the total estimated costs for each contract (cost-to-cost method). Using the cost-to-cost method, revenue is recorded at amounts equal to the ratio of actual cumulative costs incurred divided by total estimated costs at completion, multiplied by the total estimated contract revenue, less the cumulative revenue recognized in prior periods. The profit recorded on a contract using this method is equal to the current estimated total profit margin multiplied by the cumulative revenue recognized, less the amount of cumulative profit previously recorded for the contract in prior periods. As this method relies on the substantial use of estimates, these projections may be revised throughout the life of a contract. Components of this formula and ratio that may be estimated include gross profit margin and total costs at completion. The cost performance and estimates to complete on long-term contracts are reviewed, at a minimum, on a quarterly basis, as well as when information becomes available that would necessitate a review of the current estimate. Adjustments to estimates for a contract’s estimated costs at completion and estimated profit or loss often are required as experience is gained, and as more information is obtained, even though the scope of work required under the contract may or may not change, or if contract modifications occur. The impact of such adjustments or changes to estimates is made on a cumulative basis in the period when such information has become known. In 2018, 2017 and 2016, income from operations included net favorable/(unfavorable) catch-up adjustments approximating $1,400 , $600 and $(700) , respectively. Gross profit is affected by a variety of factors, including the mix of products, systems and services, production efficiencies, price competition and general economic conditions. Revenue and profits on cost-reimbursable type contracts are recognized as allowable costs, and are incurred on the contract at an amount equal to the allowable costs plus the estimated profit on those costs. The estimated profit on a cost-reimbursable contract may be fixed or variable based on the contractual fee arrangement. Incentive and award fees on these contracts are recorded as revenue when the criteria under which they are earned are reasonably assured of being met and can be estimated. For contracts in which anticipated total costs exceed the total expected revenue, an estimated loss is recognized in the period when identifiable. A provision for the entire amount of the estimated loss is recorded on a cumulative basis. The estimated remaining costs to complete loss contracts as of September 30, 2018 was $12,200 and is recorded as a reduction to gross margin on the Consolidated Statements of Operations and Comprehensive Income (Loss). This loss had an immaterial impact on Griffon's Consolidated Financial Statements. Amounts representing contract change orders or claims are included in revenue only when they can be reliably estimated and their realization is probable, and are determined on a percentage-of-completion basis measured by the cost-to-cost method. From time to time, Telephonics may combine contracts if they are negotiated together, have specific requirements to combine, or are otherwise closely related. Contracts are segmented based on customer requirements. Accounts receivable, allowance for doubtful accounts and concentrations of credit risk Accounts receivable is composed principally of trade accounts receivable, that arise from the sale of goods or services on account, and is stated at historical cost. A substantial portion of Griffon’s trade receivables are from customers of HBP, of which the largest customer is Home Depot, whose financial condition is dependent on the construction and related retail sectors of the economy. As a percentage of consolidated accounts receivable, U.S. Government related programs were 8% and Home Depot was 20% . Griffon performs continuing evaluations of the financial condition of its customers, and although Griffon generally does not require collateral, letters of credit may be required from customers in certain circumstances. Trade receivables are recorded at the stated amount, less allowance for doubtful accounts and, when appropriate, for customer program reserves and cash discounts. The allowance represents estimated uncollectible receivables associated with potential customer defaults on contractual obligations (usually due to customers’ potential insolvency). The allowance for doubtful accounts includes amounts for certain customers where a risk of default has been specifically identified, as well as an amount for customer defaults based on a formula when it is determined the risk of some default is probable and estimable, but cannot yet be associated with specific customers. The provision related to the allowance for doubtful accounts is recorded in Selling, general and administrative ("SG&A") expenses. The Company writes-off accounts receivable when they are deemed to be uncollectible. Customer program reserves and cash discounts are netted against accounts receivable when it is customer practice to reduce invoices for these amounts. The amounts netted against accounts receivable in 2018 and 2017 were $15,530 and $11,249 , respectively. All accounts receivable amounts are expected to be collected in less than one year. The Company does not currently have customers or contracts that prescribe specific retainage provisions. Contract costs and recognized income not yet billed Contract costs and recognized income not yet billed consists of amounts accounted for under the percentage of completion method of accounting, recoverable costs and accrued profit that cannot yet be invoiced under the terms of certain long-term contracts. Amounts will be invoiced when applicable contract terms, such as the achievement of specified milestones or product delivery, are met. At September 30, 2018 and 2017, approximately $29,500 and $20,100 , respectively, of contract costs and recognized income not yet billed were expected to be collected after one year. As of September 30, 2018 and 2017, the unbilled receivable balance included $ 400 and $2,850 , respectively, of reserves for contract risk. Inventories Inventories, stated at the lower of cost (first-in, first-out or average) or market, include material, labor and manufacturing overhead costs. Griffon’s businesses typically do not require inventory that is susceptible to becoming obsolete or dated. In general, Telephonics sells products in connection with programs authorized and approved under contracts awarded by the U.S. Government or agencies thereof and in accordance with customer specifications. HBP produces doors, organizational and storage products and long-handled tools and landscaping products in response to orders from customers of retailers and dealers or based on expected orders, as applicable. Property, plant and equipment Property, plant and equipment includes the historical cost of land, buildings, equipment and significant improvements to existing plant and equipment or, in the case of acquisitions, a fair market value appraisal of such assets completed at the time of acquisition. Expenditures for maintenance, repairs and minor renewals are expensed as incurred. When property or equipment is sold or otherwise disposed of, the related cost and accumulated depreciation is removed from the respective accounts and the gain or loss is recognized. No event or indicator of impairment occurred during the three years ended September 30, 2018 , which would require additional impairment testing of property, plant and equipment. Depreciation expense, which includes amortization of assets under capital leases, was $46,733 , $41,220 and $39,734 for the years ended September 30, 2018 , 2017 and 2016, respectively, and was calculated on a straight-line basis over the estimated useful lives of the assets. Depreciation included in SG&A expenses was $16,306 , $12,995 and $11,721 for the years ended September 30, 2018 , 2017 and 2016. The remaining components of depreciation, attributable to manufacturing operations, are included in Cost of goods and services. Estimated useful lives for property, plant and equipment are as follows: buildings and building improvements, 25 to 40 years ; machinery and equipment, 2 to 15 years and leasehold improvements, over the term of the lease or life of the improvement, whichever is shorter. Capitalized interest costs included in Property, plant and equipment were $2,896 , $4,891 and $3,956 for the years ended September 30, 2018 , 2017 and 2016, respectively. The original cost of fully-depreciated property, plant and equipment remaining in use at September 30, 2018 was approximately $213,501 . Goodwill and indefinite-lived intangibles Goodwill is the excess of the acquisition cost of a business over the fair value of the identifiable net assets acquired. Goodwill is not amortized, but is subject to an annual impairment test unless during an interim period, impairment indicators such as a significant change in the business climate exist. Griffon performed its annual impairment testing of goodwill as of September 30, 2018 . The performance of the test involves a two-step process. The first step involves comparing the fair value of Griffon’s reporting units with the reporting unit’s carrying amount, including goodwill. Griffon generally determines the fair value of its reporting units using the income approach methodology of valuation that includes the present value of expected future cash flows. This method uses market assumptions specific to Griffon’s reporting units. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, Griffon performs the second step of the goodwill impairment test to determine the amount of impairment loss. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. Griffon defines its reporting units as its two reportable segments: HBP and Defense Electronics. At September 30, 2018 , HBP consisted of two components, AMES and CBP, because of their similar economic and qualitative characteristics. Griffon used 5 year projections and a 3.0% terminal value to which discount rates between 7% and 9.5% were applied to calculate each unit’s fair value. To substantiate fair values derived from the income approach methodology of valuation, the implied fair value was compared to the marketplace fair value of a comparable industry grouping for reasonableness. Further, the fair values were reconciled to Griffon’s market capitalization. Both market comparisons supported the implied fair values. Any changes in key assumptions or management judgment with respect to a reporting unit or its prospects, which may result from a decline in Griffon’s stock price, a change in market conditions, market trends, interest rates or other factors outside Griffon’s control, or significant underperformance relative to historical or project future operating results, could result in a significantly different estimate of the fair value of the reporting units, which could result in a future impairment charge (level 3 inputs). Based upon the results of the annual impairment review, it was determined that the fair value of each reporting unit substantially exceeded the carrying value of the assets, as performed under step one, and no impairment existed. Similar to goodwill, Griffon tests indefinite-lived intangible assets at least annually and when indicators of impairment exist. Griffon uses a relief from royalty method to calculate and compare the fair value of the intangible to its book value. This method uses market assumptions specific to Griffon’s reporting units, which are reasonable and supportable. If the fair value is less than the book value of the indefinite-lived intangibles, an impairment charge would be recognized. There was no impairment related to goodwill or indefinite-lived intangibles during the three years ending September 30, 2018 . Definite-lived long-lived assets Amortizable intangible assets are carried at cost less accumulated amortization. For financial reporting purposes, definite-lived intangible assets are amortized on a straight-line basis over their useful lives, generally eight to twenty-five years . Long-lived assets and certain identifiable intangible assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. There were no indicators of impairment during the three years ending September 30, 2018 . Income taxes Income taxes are accounted for under the liability method. Deferred taxes reflect the tax consequences on future years of differences between the tax basis of assets and liabilities and their financial reporting amounts. The carrying value of Griffon’s deferred tax assets is dependent upon Griffon’s ability to generate sufficient future taxable income in certain tax jurisdictions. Should Griffon determine that it is more likely than not that some portion of the deferred tax assets will not be realized, a valuation allowance against the deferred tax assets would be established in the period such determination was made. Griffon provides for uncertain tax positions and any related interest and penalties based upon Management’s assessment of whether a tax benefit is more likely than not of being sustained upon examination by tax authorities. At September 30, 2018 Griffon believes that it has appropriately accounted for all unrecognized tax benefits. As of September 30, 2018 , 2017 and 2016, Griffon has recorded unrecognized tax benefits in the amount of $4,519 , $4,825 and $4,709 , respectively. Accrued interest and penalties related to income tax matters are recorded in the provision for income taxes. On December 22, 2017, the "Tax Cuts and Jobs Act" ("TCJA") was signed into law, significantly impacting several sections of the Internal Revenue Code. ASC 740, Accounting for Income Taxes , requires companies to recognize the effect of tax law changes in the period of enactment even though the effective date for most provisions is for tax years beginning after December 31, 2017, or in the case of certain other provisions, January 1, 2018. Though certain key aspects of the TCJA are effective January 1, 2018 and have an immediate accounting effect, other significant provisions are not effective or may not result in accounting effects for September 30 fiscal year companies until October 1, 2018. Given the significance of the TCJA, the SEC staff issued Staff Accounting Bulletin No. 118 ("SAB 118"), which allows registrants to record provisional amounts during a one year “measurement period”. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. Among the significant changes to the U.S. Internal Revenue Code, the TCJA lowers the U.S. federal corporate income tax rate (“Federal Tax Rate”) from 35% to 21% effective January 1, 2018. The Company computed its income tax expense for the September 30, 2018 fiscal year using a blended Federal Tax Rate of 24.5% . The 21% Federal Tax Rate will apply to fiscal years ending September 30, 2019 and each year thereafter. The Company has recorded provisional amounts for the effects of the TCJA where accounting is not complete, but a reasonable estimate has been determined. As of September 30, 2018, the Company recorded a $20,587 benefit on the revaluation of deferred tax liabilities as a provisional amount for the re-measurement of deferred tax assets and liabilities, as well as an amount for deductible executive compensation expense, both of which have been reflected in the tax provision for the year ended September 30, 2018. The TCJA requires companies to pay a one-time transition tax on mandatory deemed repatr

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Griffon accounts for acquisitions under the acquisition method, in which assets acquired and liabilities assumed are recorded at fair value as of the date of acquisition using a method substantially similar to the goodwill impairment test methodology (level 3 inputs). The operating results of the acquired companies are included in Griffon’s consolidated financial statements from the date of acquisition; in each instance, Griffon is in the process of finalizing the initial purchase price allocation. On June 4, 2018, CBP completed the acquisition of 100% of the outstanding stock of CornellCookson, a leading US manufacturer and marketer of rolling steel door and grille products designed for commercial, industrial, institutional and retail use, for approximately $180,000 , excluding the estimated present value of tax benefits, and $12,426 of post-closing adjustments, primarily consisting of a working capital adjustment, of which $9,219 was paid in October 2018. 2018 CornellCookson revenue was $66,654 . The acquisition of CornellCookson substantially expanded CBP’s non-residential product offerings, and added an established professional dealer network focused on rolling steel door and grille products for commercial, industrial, institutional and retail use. There is no other contingent consideration arrangement relative to the acquisition of CornellCookson. CornellCookson’s accounts, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, and results of operations are included in the Company’s consolidated financial statements from the date of acquisition. The Company has recorded a preliminary allocation of the purchase price to the Company’s tangible and identifiable intangible assets acquired and liabilities assumed based on their fair market values (level 3 inputs) at the acquisition date. The excess of the purchase price over the fair value of the net tangible and intangible assets was recorded as goodwill and is deductible for tax purposes. Goodwill recognized at the acquisition date represents the other intangible benefits that the Company will derive from the ownership of CornellCookson, however, such intangible benefits do not meet the criteria for recognition of separately identifiable intangible assets. The calculation of the preliminary purchase price allocation, which is pending finalization of tax-related items and completion of the related final valuation, is as follows: Accounts receivable (1) $ 30,400 Inventories (2) 12,336 Property, plant and equipment 49,426 Goodwill 42,883 Intangible assets 67,600 Other current and non-current assets 2,648 Total assets acquired 205,293 Accounts payable and accrued liabilities 12,207 Long-term liabilities 660 Total liabilities assumed 12,867 Total $ 192,426 (1) Includes $30,818 of gross accounts receivable of which $418 was not expected to be collected. The fair value of accounts receivable approximated book value acquired. (2) Includes $13,433 of gross inventory of which $1,098 was reserved for obsolete items. The preliminary amounts assigned to goodwill and major intangible asset classifications, all of which are tax deductible, for the CornellCookson acquisition are as follows: Average Goodwill $ 42,883 N/A Indefinite-lived intangibles 53,500 N/A Definite-lived intangibles 14,100 12 Total goodwill and intangible assets $ 110,483 On February 13, 2018, AMES acquired 100% of the outstanding stock of Kelkay Limited ("Kelkay"), a leading United Kingdom manufacturer and distributor of decorative outdoor landscaping products sold to garden centers, retailers and grocers in the UK and Ireland for $56,118 (GBP 40,452 ), subject to contingent consideration of up to GBP 7,000 . This acquisition broadened AMES' product offerings in the market and increased its in-country operational footprint. The purchase price was primarily allocated to tradenames of GBP 19,000 , customer related intangibles of GBP 6,640 , accounts receivable and inventory of GBP 8,894 and fixed assets and land of GBP 8,241 . On November 6, 2017, AMES acquired 100% of the assets of Harper Brush Works ("Harper"), a division of Horizon Global, for $4,383 , inclusive of post-closing adjustments. Harper is a leading U.S. manufacturer of cleaning products for professional, home, and industrial use. The acquisition expanded AMES’ long-handled tool offering in North America to include brooms, brushes, and other cleaning tools and accessories. The purchase price was primarily allocated to intangible assets of $2,300 . On October 2, 2017, Griffon Corporation completed the acquisition of 100% of the outstanding stock of ClosetMaid, a market leader of home storage and organization products, for approximately $185,700 , inclusive of certain post-closing adjustments and excluding the present value of net tax benefits resulting from the transaction. The acquisition of ClosetMaid expanded Griffon’s Home and Building Products segment into the highly complementary home storage and organization category with a leading brand and product portfolio. 2018 ClosetMaid revenue was $311,568 . ClosetMaid's accounts, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, and results of operations, are included in the Company’s consolidated financial statements from the date of acquisition. The Company has recorded a preliminary allocation of the purchase price to the Company’s tangible and identifiable intangible assets acquired and liabilities assumed based on their fair market values (level 3 inputs) at the acquisition date. The excess of the purchase price over the fair value of the net tangible and intangible assets was recorded as goodwill and is deductible for tax purposes. Goodwill recognized at the acquisition date represents the other intangible benefits that the Company will derive from the ownership of ClosetMaid, however, such intangible benefits do not meet the criteria for recognition of separately identifiable intangible assets. The following unaudited proforma summary from continuing operations presents consolidated information as if the Company acquired ClosetMaid on October 1, 2016: Proforma Revenue $ 1,823,497 Income from continuing operations 15,070 Griffon did not include any material, nonrecurring proforma adjustments directly attributable to the business combination in the proforma revenue and earnings. These proforma amounts have been compiled by adding the historical results from continuing operations of Griffon, restated for classifying the results of operations of the PPC business as a discontinued operation, to the historical results of ClosetMaid after applying Griffon’s accounting policies and the following proforma adjustments: • Additional depreciation and amortization that would have been charged assuming the preliminary fair value adjustments to property, plant, and equipment, and intangible assets had been applied from October 1, 2016. • Elimination of intercompany interest income recorded on ClosetMaid’s financial statements earned on an intercompany receivable due from ClosetMaid’s former parent. • Additional interest and related expenses from the add-on offering of $275,000 for the aggregate principal amount of 5.25% senior notes due 2022 that Griffon used to acquire ClosetMaid. • Removal of $900 of restructuring costs from ClosetMaid's historical results for the year ended September 30, 2017. • The consequential tax effects of the above adjustments using a 39.7% tax rate for the year ended September 30, 2017. The calculation of the preliminary purchase price allocation, which is pending finalization of tax-related items and completion of the related final valuation, is as follows: Accounts receivable (1) $ 32,234 Inventories (2) 28,411 Property, plant and equipment 47,464 Goodwill 70,159 Intangible assets 74,580 Other current and non-current assets 3,852 Total assets acquired 256,700 Accounts payable and accrued liabilities 68,251 Long-term liabilities 2,720 Total liabilities assumed 70,971 Total $ 185,729 (1) Includes $32,298 of gross accounts receivable of which $332 was not expected to be collected. The fair value of accounts receivable approximated book value acquired. (2) Includes $1,500 in inventory basis step-up, which was charged to cost of goods sold over the inventory turns of the acquired entity. The amounts assigned to goodwill and major intangible asset classifications, all of which are tax deductible, for the ClosetMaid acquisition are as follows: Average Goodwill $ 70,159 N/A Indefinite-lived intangibles 47,740 N/A Definite-lived intangibles 26,840 21 Total goodwill and intangible assets $ 144,739 On September 29, 2017, AMES Australia completed the acquisition of Tuscan Landscape Group Pty, Ltd. ("Tuscan Path") for approximately $18,000 (AUD 22,250 ). Tuscan Path is a leading Australian provider of pots, planters, pavers, decorative stone, and garden decor products. The acquisition of Tuscan Path broadens AMES' outdoor living and lawn and garden business, and will strengthen AMES' industry leading position in Australia. The purchase price was primarily allocated to intangible assets of AUD 3,900 and inventory and accounts receivable of AUD 7,900 . On July 31, 2017, The AMES Companies, Inc. acquired La Hacienda Limited, a leading United Kingdom outdoor living brand of unique heating and garden decor products, for approximately $11,400 (GBP 9,175 ), including an approximate contingent earn out payment of $790 (GBP 600 ). The acquisition of La Hacienda broadens AMES' global outdoor living and lawn and garden business and supports AMES' UK expansion strategy. The purchase price allocation was primarily allocated to intangible assets of approximately GBP 3,100 and inventory and accounts receivable of GBP 4,200 . On December 30, 2016, AMES Australia acquired Home Living ("Hills") for approximately $6,051 (AUD 8,400 ). The purchase price has been allocated to acquired assets and assumed liabilities and primarily consists of inventory, tooling and identifiable intangible assets, including trademarks, intellectual property and customer relationships. Hills, founded in 1946, is a market leader in the supply of clothesline, laundry and garden products. The Hills acquisition adds to AMES' existing broad category of products and enhances its lawn and garden product offerings in Australia. The purchase price was primarily allocated to intangible assets of approximately AUD 6,400 with the remainder primarily inventory. On February 14, 2016, AMES Australia acquired substantially all of the Intellectual Property (IP) assets of Australia-based Nylex Plastics Pty Ltd. for $1,744 (AUD 2,452 ). Through this acquisition, AMES and Griffon secured the ownership of the trademark “Nylex” for certain categories of AMES products, principally in the country of Australia. Previously, the Nylex name was licensed. The acquisition of the Nylex IP was contemplated as a post-closing activity of the Cyclone acquisition and supports AMES' Australian watering products strategy. The purchase price was allocated to indefinite lived trademarks and is not deductible for income taxes. In December 2015, Telephonics invested an additional $2,726 increasing its equity stake from 26% to 49% in Mahindra Telephonics Integrated Systems ("MTIS"), a joint venture with Mahindra Defence Systems, a Mahindra Group Company. MTIS is an aerospace and defense manufacturing and development facility in Prithla, India. This investment is accounted for using the equity method. SG&A and Cost of goods and services included $6,097 and $1,500 of acquisition-related costs, respectively, in 2018. SG&A included $9,617 acquisition-related costs in 2017 and acquisition-related costs included in SG&A in 2016 were not material.

INVENTORIES

INVENTORIES	12 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES The following table details the components of inventory: At September 30, At September 30, Raw materials and supplies $ 97,645 $ 67,990 Work in process 83,578 78,846 Finished goods 217,136 152,601 Total $ 398,359 $ 299,437

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT The following table details the components of property, plant and equipment, net: At September 30, At September 30, Land, building and building improvements $ 130,296 $ 71,764 Machinery and equipment 544,875 462,173 Leasehold improvements 50,111 43,040 725,282 576,977 Accumulated depreciation and amortization (382,790 ) (344,842 ) Total $ 342,492 $ 232,135

GOODWILL AND OTHER INTANGIBLES

GOODWILL AND OTHER INTANGIBLES	12 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLES	GOODWILL AND OTHER INTANGIBLES The following table provides changes in carrying value of goodwill by segment through the year ended September 30, 2018 : At September 30, Goodwill from acquisitions Foreign currency translation adjustments September 30, Goodwill from acquisitions Foreign currency translation adjustments September 30, Home & Building Products $ 287,618 $ 12,417 $ 559 $ 300,594 $ 119,907 $ 349 $ 420,850 Defense Electronics 18,545 — — 18,545 — — 18,545 Total $ 306,163 $ 12,417 $ 559 $ 319,139 $ 119,907 $ 349 $ 439,395 The following table provides the gross carrying value and accumulated amortization for each major class of intangible asset: At September 30, 2018 At September 30, 2017 Gross Carrying Amount Accumulated Amortization Average Life (Years) Gross Carrying Amount Accumulated Amortization Customer relationships & other $ 186,031 $ 49,822 23 $ 152,025 $ 43,421 Unpatented technology 19,004 6,238 13 6,193 4,719 Total amortizable intangible assets 205,035 56,060 158,218 48,140 Trademarks 221,883 — 95,049 — Total intangible assets $ 426,918 $ 56,060 $ 253,267 $ 48,140 Amortization expense for intangible assets subject to amortization was $9,070 , $6,658 and $6,608 for the years ended September 30, 2018 , 2017 and 2016, respectively. Amortization expense for each of the next five years and thereafter, based on current intangible balances and classifications, is estimated as follows: 2019 - $9,285 ; 2020 - $8,825 ; 2021 - $8,825 ; 2022 - $8,825 and 2023 - $8,746 ; thereafter - $104,469 . No event or indicator or impairment occurred during the current year, which would require impairment testing of long-lived intangible assets including goodwill.

DISCONTINUED OPERATIONS

DISCONTINUED OPERATIONS	12 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
DISCONTINUED OPERATIONS	DISCONTINUED OPERATIONS PPC On November 16, 2017, Griffon announced it entered into a definitive agreement to sell PPC and on February 6, 2018, completed the sale to Berry for approximately $475,000 . As a result, Griffon classified the results of operations of the PPC business as discontinued operations in the Consolidated Statements of Operations for all periods presented and classified the related assets and liabilities associated with the discontinued operations in the consolidated balance sheets. PPC is a global leader in the development and production of embossed, laminated and printed specialty plastic films for hygienic, health-care and industrial products and sells to some of the world's largest consumer products companies. In connection with the sale of PPC, the Company recorded a gain of $112,964 ( 81,041 , net of tax) during the year ended September 30, 2018. The tax computed on the PPC gain is preliminary and is subject to finalization. The following amounts related to the PPC segment have been segregated from Griffon's continuing operations and are reported as discontinued operations: For the Year Ended September 30, 2018 2017 2016 Revenue $ 166,262 $ 460,914 $ 480,126 Cost of goods and services 132,100 389,416 407,385 Gross profit 34,162 71,498 72,741 Selling, general and administrative expenses 26,303 43,518 45,673 Restructuring charges — — 5,900 Total operating expenses 26,303 43,518 51,573 Income from discontinued operations 7,859 27,980 21,168 Other income (expense) Gain on sale of business 112,964 — — Interest expense, net (155 ) (63 ) (1,234 ) Other, net (687 ) 59 1,018 Total other income (expense) 112,122 (4 ) (216 ) Income from operations of discontinued operations 119,981 27,976 20,952 The Company has no assets or liabilities classified as held for sale as of September 30, 2018. The following amounts related to PPC have been segregated from Griffon's continuing operations and are reported as assets and liabilities of discontinued operations held for sale in the consolidated balance sheet at September 30, 2017: At September 30, 2017 ASSETS Accounts receivable, net $ 51,768 Inventories, net 45,742 Prepaid and other current assets 11,000 PROPERTY, PLANT AND EQUIPMENT, net 185,940 GOODWILL 57,087 INTANGIBLE ASSETS, net 12,298 OTHER ASSETS 6,889 Total Assets Held for Sale $ 370,724 LIABILITIES Notes payable and current portion of long-term debt $ 11,163 Accounts payable 36,619 Accrued liabilities 14,553 LONG-TERM DEBT, net 10,549 OTHER LIABILITIES 11,566 Total Liabilities Held for Sale $ 84,450 Installation Services and Other Discontinued Activities In 2008, as a result of the downturn in the residential housing market, Griffon exited substantially all operating activities of its Installation Services segment which sold, installed and serviced garage doors and openers, fireplaces, floor coverings, cabinetry and a range of related building products, primarily for the new residential housing market. In 2008, Griffon sold eleven units, closed one unit and merged two units into CBP. Griffon substantially concluded its remaining disposal activities in 2009. Installation Services operating results have been reported as discontinued operations in the Consolidated Statements of Operations and Comprehensive Income (Loss) for all periods presented; Installation Services is excluded from segment reporting. There was no reported revenue in 2018, 2017 and 2016. During the year ended September 30, 2017, Griffon recorded $5,700 of reserves in discontinued operations related to historical environmental remediation efforts and to increase the reserve for homeowner association claims (HOA) related to the Clopay Services Corporation discontinued operations in 2008. The following amounts summarize the total assets and liabilities of PPC and Installation Services and other discontinued activities which have been segregated from Griffon’s continuing operations and are reported as assets and liabilities of discontinued operations in the consolidated balance sheets: At September 30, At September 30, Assets of discontinued operations: Prepaid and other current assets $ 324 $ 329 Other long-term assets 2,916 2,960 Total assets of discontinued operations $ 3,240 $ 3,289 Liabilities of discontinued operations: Accrued liabilities, current $ 7,210 $ 8,342 Other long-term liabilities 2,648 3,037 Total liabilities of discontinued operations $ 9,858 $ 11,379 At September 30, 2018 , Griffon’s liabilities for PPC and Installations Services and other discontinued operations primarily related to insurance claims, income taxes and product liability, warranty and environmental reserves and stay and transaction bonuses totaling liabilities of approximately $9,858 .

ACCRUED LIABILITIES

ACCRUED LIABILITIES	12 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
ACCRUED LIABILITIES	ACCRUED LIABILITIES The following table details the components of accrued liabilities: At September 30, At September 30, Compensation $ 50,251 $ 37,692 Interest 4,776 3,671 Warranties and rebates 11,227 6,236 Insurance 25,329 12,216 Rent, utilities and freight 4,830 2,149 Income and other taxes 8,016 6,291 Marketing and advertising 3,685 1,859 Acquisition related accruals 17,448 — Other 13,630 13,144 Total $ 139,192 $ 83,258

WARRANTY LIABILITY

WARRANTY LIABILITY	12 Months Ended
	Sep. 30, 2018
Product Warranties Disclosures [Abstract]
WARRANTY LIABILITY	WARRANTY LIABILITY Telephonics offers warranties against product defects for periods generally ranging from one to two years , depending on the specific product and terms of the customer purchase agreement. CBP also offers warranties against product defects for periods generally ranging from one to ten years, with limited lifetime warranties on certain door models. Typical warranties require AMES, CBP and Telephonics to repair or replace the defective products during the warranty period at no cost to the customer. At the time revenue is recognized, Griffon records a liability for warranty costs, estimated based on historical experience, and periodically assesses its warranty obligations and adjusts the liability as necessary. AMES offers an express limited warranty for a period of ninety days on all products from the date of the original purchase unless otherwise stated on the product or packaging from the date of original purchase. Changes in Griffon’s warranty liability, included in Accrued liabilities, were as follows: Years Ended September 30, 2018 2017 Balance, beginning of period $ 6,236 $ 6,322 Warranties issued and changes in estimated pre-existing warranties 8,770 6,393 Actual warranty costs incurred (7,948 ) (6,479 ) Other warranty liabilities assumed from acquisitions $ 1,116 $ — Balance, end of period $ 8,174 $ 6,236

NOTES PAYABLE, CAPITALIZED LEAS

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT	12 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT	NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT The present value of the net minimum payments on capitalized leases as of September 30, 2018 was follows: At September 30, Total minimum lease payments $ 10,586 Less amount representing interest payments (812 ) Present value of net minimum lease payments 9,774 Current portion (3,579 ) Capitalized lease obligation, less current portion $ 6,195 Minimum payments under capital leases for the next five years are as follows: $4,242 in 2019 , $3,764 in 2020 , $2,102 in 2021 , $443 in 2022 , $35 in 2023 and $0 thereafter. Included in the consolidated balance sheet at September 30, 2018 under Property, plant and equipment, are costs and accumulated depreciation subject to capitalized leases of $41,742 and $31,969 , respectively, and included in Other assets are deferred interest charges of $80 . Included in the consolidated balance sheet at September 30, 2017 , under Property, plant and equipment are costs and accumulated depreciation subject to capitalized leases of $19,238 and $11,831 , respectively, and included in Other assets are deferred interest charges of $105 . Amortization expense was $3,514 , $1,683 , and $1,628 in 2018 , 2017 and 2016 respectively. In October 2006, a subsidiary of Griffon entered into a capital lease totaling $14,290 for real estate it occupies in Troy, Ohio. Approximately $10,000 was used to acquire the building and the remaining amount was used for improvements. The lease matures in 2022 , bears interest at a fixed rate of 5.0% , is secured by a mortgage on the real estate and is guaranteed by Griffon. Debt at September 30, 2018 and 2017 consisted of the following: At September 30, 2018 Outstanding Balance Original Issuer Discount Capitalized Fees & Expenses Balance Sheet Coupon Interest Rate Senior note due 2022 (a) $ 1,000,000 1,220 $ (12,968 ) $ 988,252 5.25 % Revolver due 2021 (b) 25,000 — (1,413 ) 23,587 n/a ESOP Loans (e) 34,694 — (186 ) 34,508 n/a Capital lease - real estate (f) 7,503 — (80 ) 7,423 5.00 % Non U.S. lines of credit (g) 7,951 (16 ) 7,935 n/a Non U.S. term loans (g) 53,533 — (148 ) 53,385 n/a Other long term debt (h) 6,011 — (19 ) 5,992 n/a Totals 1,134,692 1,220 (14,830 ) 1,121,082 less: Current portion (13,011 ) — — (13,011 ) Long-term debt $ 1,121,681 $ 1,220 $ (14,830 ) $ 1,108,071 At September 30, 2017 Outstanding Balance Original Issuer Discount Capitalized Balance Sheet Coupon Interest Rate Senior notes due 2022 (a) $ 725,000 $ (1,177 ) $ (9,220 ) $ 714,603 5.25 % Revolver due 2021 (b) 144,216 — (1,951 ) 142,265 n/a Real estate mortgages (d) 23,642 — (320 ) 23,322 n/a ESOP Loans (e) 42,675 — (310 ) 42,365 n/a Capital lease - real estate (f) 5,312 — (105 ) 5,207 5.00 % Non U.S. lines of credit (g) 9,402 (31 ) 9,371 n/a Non U.S. term loans (g) 35,943 — (108 ) 35,835 n/a Other long term debt (h) 6,211 — (21 ) 6,190 Totals 992,401 (1,177 ) (12,066 ) 979,158 less: Current portion (11,078 ) — — (11,078 ) Long-term debt $ 981,323 $ (1,177 ) $ (12,066 ) $ 968,080 Interest expense consists of the following for the years ended September 30, 2018 , 2017 and 2016. Year Ended September 30, 2018 Effective Interest Rate Cash Interest Amort. Debt Discount Amort. Deferred Cost & Other Fees Total Interest Expense Senior notes due 2022 (a) 5.66 % 52,500 270 3,803 56,573 Revolver due 2020 (b) n/a 3,718 — 565 4,283 Convert. debt due 2017 (c) n/a — — — — Real estate mortgages (d) 3.3 % 349 — 320 669 ESOP Loans (e) 6.3 % 1,802 — 124 1,926 Capital lease - real estate (f) n/a 581 — 25 606 Non U.S. lines of credit (g) n/a 34 — 15 49 Non U.S. term loans (g) n/a 1,420 — 90 1,510 Other long term debt (h) n/a 494 7 501 Capitalized interest (549 ) — — (549 ) Totals $ 60,349 $ 270 $ 4,949 $ 65,568 Year Ended September 30, 2017 Effective Interest Rate Cash Interest Amort. Debt Discount Amort. Deferred Cost & Other Fees Total Interest Expense Senior notes due 2022 (a) 5.55 % 38,063 270 1,857 40,190 Revolver due 2020 (b) n/a 4,951 — 567 5,518 Convert. debt due 2017 (c) 8.9 % 1,167 1,248 148 2,563 Real estate mortgages (d) 2.6 % 582 — 58 640 ESOP Loans (e) 4.2 % 1,557 — 133 1,690 Capital lease - real estate (f) 5.5 % 296 — 25 321 Non U.S. lines of credit (g) n/a 76 — 128 204 Non U.S. term loan (g) n/a 860 — 67 927 Other long term debt (h) 245 10 255 Capitalized interest (795 ) — — (795 ) Totals 47,002 1,518 2,993 51,513 Year Ended September 30, 2016 Effective Interest Rate Cash Interest Amort. Debt Discount Amort. Deferred Cost & Other Fees Total Interest Expense Senior notes due 2022 (a) 5.48 % 33,906 103 1,481 35,490 Revolver due 2020 (b) n/a 2,564 — 512 3,076 Convert. debt due 2017 (c) 9.0 % 4,000 4,346 443 8,789 Real estate mortgages (d) 2.2 % 439 — 62 501 ESOP Loans (e) 3.1 % 1,090 — 236 1,326 Capital lease - real estate (f) 5.5 % 353 — 25 378 Non U.S. lines of credit (g) n/a 553 — 91 644 Non U.S. term loan (g) n/a 659 — 13 672 Other long term debt (h) 260 9 269 Capitalized interest (1,202 ) — — (1,202 ) Totals $ 42,622 $ 4,449 $ 2,872 $ 49,943 Minimum payments under debt agreements for the next five years are as follows: $13,011 in 2019 , $43,330 in 2020 , $6,802 in 2021 , $5,233 in 2022 , $4,827 in 2023 and $1,061,489 thereafter. (a) On October 2, 2017, in an unregistered offering through a private placement under Rule 144A, Griffon completed the add-on offering of $275,000 principal amount of its 5.25% senior notes due 2022, at 101.0% of par, to Griffon's previously issued $125,000 principal amount of its 5.25% senior notes due 2022, at 98.76% of par, completed on May 18, 2016 and $600,000 5.25% senior notes due in 2022 , at par, which was completed on February 27, 2014 (collectively the “Senior Notes”). As of September 30, 2018, outstanding Senior Notes due totaled $1,000,000 ; interest is payable semi-annually on March 1 and September 1. The net proceeds of the $275,000 add-on offering were used to acquire ClosetMaid with the remaining proceeds used to pay down outstanding loan borrowings under Griffon's Revolving Credit Facility (the "Credit Agreement"). The net proceeds of the previously issued $125,000 add-on offering were used to pay down outstanding revolving loan borrowings under the Credit Agreement. Proceeds from the $600,000 5.25% senior notes due in 2022 were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a call and tender offer premium of $31,530 and to make interest payments of $16,716 , with the balance used to pay a portion of the related transaction fees and expenses. In connection with the issuance of the Senior Notes, all obligations under the $550,000 of 7.125% senior notes due in 2018 were discharged. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On February 5, 2018, July 20, 2016 and June 18, 2014, Griffon exchanged all of the $275,000 , $125,000 and $600,000 Senior Notes, respectively, for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer. The fair value of the Senior Notes approximated $990,000 on September 30, 2018 based upon quoted market prices (level 1 inputs). In connection with the issuance and exchange of the $275,000 senior notes, Griffon capitalized $8,472 of underwriting fees and other expenses; in addition to $13,329 capitalized under the previously issued $725,000 Senior Notes. All capitalized fees for the Senior Notes will amortize over the term of the notes and, at September 30, 2018, $14,830 remained to be amortized. (b) On March 22, 2016, Griffon amended its Credit Agreement to increase the credit facility from $250,000 to $350,000 , extend its maturity from March 13, 2020 to March 22, 2021, and modify certain other provisions of the facility. On October 2, 2017 and on May 31, 2018, Griffon amended the Credit Agreement in connection with the ClosetMaid and the CornellCookson acquisitions, respectively, to modify the net leverage covenant. The facility includes a letter of credit sub-facility with a limit of $50,000 and a multi-currency sub-facility of $100,000 . The Credit Agreement provides for same day borrowings of base rate loans. Borrowings under the Credit Agreement may be repaid and re-borrowed at any time, subject to final maturity of the facility or the occurrence of an event of default under the Credit Agreement. Interest is payable on borrowings at either a LIBOR or base rate benchmark rate, in each case without a floor, plus an applicable margin, which adjusts based on financial performance. Current margins are 1.75% for base rate loans and 2.75% for LIBOR loans. The Credit Agreement has certain financial maintenance tests including a maximum total leverage ratio, a maximum senior secured leverage ratio and a minimum interest coverage ratio, as well as customary affirmative and negative covenants and events of default. The negative covenants place limits on Griffon's ability to, among other things, incur indebtedness, incur liens, and make restricted payments and investments. Borrowings under the Credit Agreement are guaranteed by Griffon’s material domestic subsidiaries and are secured, on a first priority basis, by substantially all domestic assets of the Company and the guarantors, and a pledge of not greater than 65% of the equity interest in Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon’s material domestic subsidiaries securing a limited amount of the debt under the credit agreement relating to Griffon's Employee Stock Ownership Plan ("ESOP") ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (e) below). At September 30, 2018 , under the Credit Agreement, there were $25,000 outstanding borrowings; outstanding standby letters of credit were $14,623 ; and $310,377 was available, subject to certain loan covenants, for borrowing at that date. (c) On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000 , if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858 , or 1,954,993 shares of common stock issued from treasury. (d) In September 2015 and March 2016, Griffon entered into mortgage loans in the amount of $32,280 and $8,000 , respectively, and were due to mature in September 2025 and April 2018, respectively. The mortgage loans were secured and collateralized by four properties occupied by Griffon's subsidiaries and were guaranteed by Griffon. The loans had an interest at a rate of LIBOR plus 1.50% . The loans were paid off during the year ended September 30, 2018. (e) In August 2016, Griffon’s ESOP entered into an agreement that refinanced the existing ESOP loan into a new Term Loan in the amount of $35,092 (the "Agreement"). The Agreement also provided for a Line Note with $10,908 available to purchase shares of Griffon common stock in the open market. During 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized. On June 30, 2017, the Term Loan and Line Note were combined into a single Term Loan. The Term Loan bears interest at LIBOR plus 3.0% . The Term Loan requires quarterly principal payments of $569 with a balloon payment due at maturity on March 22, 2020. As a result of the special cash dividend of $1.00 per share, paid on April 16, 2018, the outstanding balance of the Term Loan was reduced by $5,705 . As of September 30, 2018 , $34,508 , net of issuance costs, was outstanding under the Term Loan. The Term Loan is secured by shares purchased with the proceeds of the loan and with a lien on a specific amount of Griffon assets (which lien ranks pari passu with the lien granted on such assets under the Credit Agreement) and is guaranteed by Griffon. (f) Two Griffon subsidiaries have capital leases outstanding for real estate located in Troy, Ohio and Ocala, Florida. The leases mature in 2021 and 2022, respectively, and bear interest at fixed rates of approximately 5.0% and 8.0% , respectively. The Troy, Ohio lease is secured by a mortgage on the real estate and is guaranteed by Griffon. The Ocala, Florida lease contains two five-year renewal options. As of September 30, 2018, $7,423 was outstanding, net of issuance costs. (g) In November 2012, Garant G.P. (“Garant”) entered into a CAD 15,000 ( $11,498 as of September 30, 2018) revolving credit facility. The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum ( 3.70% LIBOR USD and 3.24% Bankers Acceptance Rate CDN as of September 30, 2018 ). The revolving facility matures in October 2019. Garant is required to maintain a certain minimum equity. As of September 30, 2018 , there were no borrowings under the revolving credit facility with CAD 15,000 ( $11,498 as of September 30, 2018 ) available for borrowing. In July 2016, Griffon Australia Holdings Pty Ltd and its Australian subsidiaries ("Griffon Australia") entered into an AUD 30,000 term loan and an AUD 10,000 revolver. The term loan refinanced two existing term loans and the revolver replaced two existing lines. In December 2016, the amount available under the revolver was increased from AUD 10,000 to AUD 20,000 and, in March 2017 the term loan commitment was increased by AUD 5,000 . In September 2017, the term commitment was increased by AUD 15,000 . The term loan requires quarterly principal payments of AUD 1,250 plus interest with a balloon payment of AUD 37,125 due upon maturity in October 2019, and accrues interest at Bank Bill Swap Bid Rate “BBSY” plus 2.00% per annum ( 3.99% at September 30, 2018 ). As of September 30, 2018 , the term had an outstanding balance of AUD 40,875 ( $29,546 as of September 30, 2018). The revolving facility matures in March 2019, but is renewable upon mutual agreement with the lender, and accrues interest at BBSY plus 2.0% per annum ( 3.90% at September 30, 2018). At September 30, 2018, the revolver had an outstanding balance of AUD 11,000 ( $7,951 at September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Griffon Australia and its subsidiaries. Griffon guarantees the term loan. Griffon Australia is required to maintain a certain minimum equity level and is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. A UK subsidiary of Griffon maintained an invoice discounting arrangement secured by trade receivables. Interest was variable at 2.0% over the Sterling base rate. This facility was canceled in July 2018. In July 2018, the AMES Companies UK Ltd and its subsidiaries ("Ames UK") entered into a GBP 14,000 term loan, GBP 4,000 mortgage loan and GBP 5,000 revolver. The term loan and mortgage loan require quarterly principal payments of GBP 350 and GBP 83 plus interest, respectively, and have balloon payments due upon maturity, July 2023, of GBP 7,000 and GBP 2,333 , respectively. The Term Loan and Mortgage Loans accrue interest at the GBP LIBOR Rate plus 2.25% and 1.8% , respectively ( 3.05% and 2.60% at September 30, 2018, respectively). The revolving facility matures in July 2019, but is renewable upon mutual agreement with the lender, and accrues interest at the Bank of England Base Rate plus 1.5% ( 2.25% as of September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Ames UK and its subsidiaries. Ames UK is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. The invoice discounting arrangement was canceled and replaced by the above loan facilities. As of September 30, 2018, outstanding borrowings on these facilities totaled $23,987 . (h) Other long-term debt primarily consists of a loan with the Pennsylvania Industrial Development Authority, with the balance consisting of capital leases. At September 30, 2018 , Griffon and its subsidiaries were in compliance with the terms and covenants of its credit and loan agreements.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	EMPLOYEE BENEFIT PLANS Griffon offers defined contribution plans to most of its U.S. employees. In addition to employee contributions to the plans, Griffon makes contributions based upon various percentages of compensation and/or employee contributions, which were $8,328 in 2018 , $8,714 in 2017 and $8,301 in 2016. The Company also provides healthcare and life insurance benefits for certain groups of retirees through several plans. For certain employees, the benefits are at fixed amounts per retiree and are partially contributory by the retiree. The post-retirement benefit obligation was $1,699 and $2,014 as of September 30, 2018 and 2017 . The accumulated other comprehensive income (loss) for these plans was $(60) and ($107) as of September 30, 2018 and 2017 , respectively, and the 2018 and 2017 benefit expense was $45 and $41 , respectively. It is the Company’s practice to fund these benefits as incurred. Griffon also has qualified and non-qualified defined benefit plans covering certain employees with benefits based on years of service and employee compensation. Over time, these amounts will be recognized as part of net periodic pension costs in the Consolidated Statements of Operations and Comprehensive Income (Loss). Griffon is responsible for overseeing the management of the investments of the qualified defined benefit plan and uses the services of an investment manager to manage these assets based on agreed upon risk profiles. The primary objective of the qualified defined benefit plan is to secure participant retirement benefits. As such, the key objective in this plan’s financial management is to promote stability and, to the extent appropriate, growth in the funded status. Financial objectives are established in conjunction with a review of current and projected plan financial requirements. The fair values of a majority of the plan assets were determined by the plans’ trustee using quoted market prices for identical instruments (level 1 inputs) as of September 30, 2018 and 2017. The fair value of various other investments was determined by the plan’s trustee using direct observable market corroborated inputs, including quoted market prices for similar assets (level 2 inputs). There were no pension assets measured using level 3 inputs. Effective January 1, 2012, the Clopay Pension Plan merged with the Ames True Temper Inc. Pension Plan. The merged qualified defined benefit plan was named the Clopay Ames Pension Plan (the “Clopay AMES Plan”). The Clopay portion of the Clopay AMES Plan has been frozen to new entrants since December 2000. Certain employees who were part of the plan prior to December 2000 continued to accrue a service benefit through December 2010, at which time all plan participants stopped accruing service benefits. The AMES portion of the Clopay AMES Plan has been frozen to all new entrants since November 2009 and stopped accruing benefits in December 2009. The AMES supplemental executive retirement plan was frozen to new entrants and participants in the plan stopped accruing benefits in 2008. In 2016, the Company changed the method used to estimate the service and interest components of net periodic benefit cost for pension and other post-retirement benefits from the single weighted-average discount rate to the spot rate method. There was no impact on the total benefit obligation. Griffon uses judgment to establish the assumptions used in determining the future liability of the plan, as well as the investment returns on the plan assets. The expected return on assets assumption used for pension expense was developed through analysis of historical market returns, current market conditions and past experience of plan investments. The long-term rate of return assumption represents the expected average rate of earnings on the funds invested, or to be invested, to provide for the benefits included in the benefit obligations. The assumption is based on several factors including historical market index returns, the anticipated long-term asset allocation of plan assets and the historical return. The discount rate assumption is determined by developing a yield curve based on high quality bonds with maturities matching the plans’ expected benefit payment stream. The plans’ expected cash flows are then discounted by the resulting year-by-year spot rates. A 10% change in the discount rate, average wage increase or return on assets would not have a material effect on the financial statements of Griffon. Net periodic costs (benefits) were as follows: Defined Benefits for the Years Ended September 30, Supplemental Benefits for the Years Ended September 30, 2018 2017 2016 2018 2017 2016 Net periodic (benefits) costs: Interest cost $ 5,084 $ 4,892 $ 5,465 $ 544 $ 715 $ 1,243 Expected return on plan assets (10,736 ) (10,943 ) (10,934 ) — — — Amortization of: Prior service costs — 1 1 14 15 19 Actuarial loss 755 1,980 1,131 628 1,347 1,224 Total net periodic (benefits) costs $ (4,897 ) $ (4,070 ) $ (4,337 ) $ 1,186 $ 2,077 $ 2,486 The tax benefits in 2018 , 2017 and 2016 for the amortization of pension costs in Other comprehensive income (loss) were $342 , $1,170 and $831 , respectively. The estimated net actuarial loss and prior service cost that will be amortized from AOCI into Net periodic pension cost during 2019 is $887 and $14 , respectively. The weighted-average assumptions used in determining the net periodic (benefits) costs were as follows: Defined Benefits for the Years Ended September 30, Supplemental Benefits for the Years Ended September 30, 2018 2017 2016 2018 2017 2016 Discount rate 4.10 % 3.64 % 3.42 % 3.99 % 3.18 % 2.86 % Expected return on assets 7.00 % 7.25 % 7.50 % — % — % — % Plan assets and benefit obligation of the defined and supplemental benefit plans were as follows: Defined Benefits at September 30, Supplemental Benefits at September 30, 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at beginning of fiscal year $ 174,337 $ 189,156 $ 32,627 $ 35,774 Interest cost 5,084 4,892 544 715 Benefits paid (10,531 ) (10,393 ) (3,001 ) (4,057 ) Actuarial (gain) loss (7,562 ) (9,318 ) (14,452 ) 195 Benefit obligation at end of fiscal year 161,328 174,337 15,718 32,627 Change in plan assets: Fair value of plan assets at beginning of fiscal year 150,822 144,316 — — Actual return on plan assets 7,940 13,152 — — Company contributions 2,449 3,747 3,001 4,057 Benefits paid (10,531 ) (10,393 ) (3,001 ) (4,057 ) Fair value of plan assets at end of fiscal year 150,680 150,822 — — Projected benefit obligation in excess of plan assets $ (10,648 ) $ (23,515 ) $ (15,718 ) $ (32,627 ) Amounts recognized in the statement of financial position consist of: Accrued liabilities $ — $ — $ (1,906 ) $ (3,984 ) Other liabilities (long-term) (10,648 ) (23,515 ) (13,812 ) (28,643 ) Total Liabilities (10,648 ) (23,515 ) (15,718 ) (32,627 ) Net actuarial losses 19,088 24,608 4,965 20,045 Prior service cost — — 28 42 Deferred taxes (6,103 ) (9,069 ) (1,597 ) (7,486 ) Total Accumulated other comprehensive loss, net of tax 12,985 15,539 3,396 12,601 Net amount recognized at September 30, $ 2,337 $ (7,976 ) $ (12,322 ) $ (20,026 ) Accumulated benefit obligations $ 161,328 $ 174,337 $ 15,718 $ 32,627 Information for plans with accumulated benefit obligations in excess of plan assets: ABO $ 161,328 $ 174,337 $ 15,718 $ 32,627 PBO 161,328 174,337 15,718 32,627 Fair value of plan assets 150,680 150,822 — — The weighted-average assumptions used in determining the benefit obligations were as follows: Defined Benefits at September 30, Supplemental Benefits at September 30, 2018 2017 2018 2017 Weighted average discount rate 4.10 % 3.64 % 3.99 % 3.18 % The actual and weighted-average asset allocation for qualified benefit plans were as follows: At September 30, 2018 2017 Target Cash and equivalents 18.0 % 18.0 % — % Equity securities 68.5 % 58.0 % 63.0 % Fixed income 9.5 % 19.3 % 37.0 % Other 4.0 % 4.7 % — % Total 100.0 % 100.0 % 100.0 % Estimated future benefit payments to retirees, which reflect expected future service, are as follows: For the years ending September 30, Defined Benefits Supplemental Benefits 2019 $ 10,767 $ 1,906 2020 10,892 1,822 2021 10,979 1,734 2022 10,960 1,642 2023 10,950 1,545 2024 through 2028 53,652 6,068 During 2018, Griffon expects to contribute $1,906 in payments related to Supplemental Benefits that will be funded from the general assets of Griffon. Griffon expects to contribute $3,114 to the Defined Benefit plan in 2019 . The Clopay AMES Plan is covered by the Pension Protection Act of 2006. The Adjusted Funding Target Attainment Percent for the plan as of January 1, 2018 was 95.8% . Since the plan was in excess of the 80% funding threshold there were no plan restrictions. The expected level of 2019 catch up contributions is $1,100 . The following is a description of the valuation methodologies used for plan assets measured at fair value: Short-term investment funds – The fair value is determined using the Net Asset Value (“NAV”) provided by the administrator of the fund. The NAV is based on the value of the underlying assets owned by the fund, minus its liabilities, and then divided by the number of shares outstanding. The NAV is a quoted price in a market that is not active and is primarily classified as Level 2. These investments can be liquidated on demand. Government and agency securities – When quoted market prices are available in an active market, the investments are classified as Level 1. When quoted market prices are not available in an active market, the investments are classified as Level 2. Equity securities – The fair values reflect the closing price reported on a major market where the individual mutual fund securities are traded in equity securities. These investments are classified within Level 1 of the valuation hierarchy. Debt securities – The fair values are based on a compilation of primarily observable market information or a broker quote in a non-active market where the individual mutual fund securities are invested in debt securities. These investments are primarily classified within Level 2 of the valuation hierarchy. Commingled funds – The fair values are determined using NAV provided by the administrator of the fund. The NAV is based on the value of the underlying assets owned by the trust/entity, minus its liabilities, and then divided by the number of shares outstanding. These investments are generally classified within Level 2 of the valuation hierarchy and can be liquidated on demand. Interest in limited partnerships and hedge funds - One limited partnership investment is a private equity fund and the fair value is determined by the fund managers based on the estimated value of the various holdings of the fund portfolio. These investments are classified within Level 2 of the valuation hierarchy. The following table presents the fair values of Griffon’s pension and post-retirement plan assets by asset category: At September 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash and equivalents $ 27,209 $ — $ — $ 27,209 Debt instruments 14,269 — — 14,269 Equity securities 41,042 — — 41,042 Commingled funds — 62,088 — 62,088 Limited partnerships and hedge fund investments — 6,026 — 6,026 Total $ 82,520 $ 68,114 $ — $ 150,634 At September 30, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash and equivalents $ 27,156 $ — $ — $ 27,156 Debt instruments 14,520 — — 14,520 Equity securities 40,423 — — 40,423 Commingled funds — 62,907 — 62,907 Limited partnerships and hedge fund investments — 5,816 — 5,816 Total $ 82,099 $ 68,723 $ — $ 150,822 Griffon has an ESOP that covers substantially all domestic employees. All U.S. employees of Griffon, who are not members of a collective bargaining unit, automatically become eligible to participate in the plan on the October 1 st following completion of one qualifying year of service (as defined in the plan). Securities are allocated to participants’ individual accounts based on the proportion of each participant’s aggregate compensation (not to exceed $275 for the plan year ended September 30, 2018 ), to the total of all participants’ compensation. Shares of the ESOP which have been allocated to employee accounts are charged to expense based on the fair value of the shares transferred and are treated as outstanding in determining earnings per share. Dividends paid on shares held by the ESOP are used to offset debt service on ESOP Loans. Dividends paid on shares held in participant accounts are utilized to allocate shares from the aggregate number of shares to be released, equal in value to those dividends, based on the closing price of Griffon common stock on the dividend payment date. Compensation expense under the ESOP was $9,532 in 2018 , $5,643 in 2017 and $3,689 in 2016. The cost of the shares held by the ESOP and not yet allocated to employees is reported as a reduction of Shareholders’ Equity. The fair value of the unallocated ESOP shares as of September 30, 2018 and 2017 based on the closing stock price of Griffon’s stock was $47,916 and $69,394 , respectively. The ESOP shares were as follows: At September 30, 2018 2017 Allocated shares 3,157,530 2,676,486 Unallocated shares 2,477,385 3,125,850 Total 5,634,915 5,802,336

INCOME TAXES

INCOME TAXES	12 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES On December 22, 2017, the "Tax Cuts and Jobs Act" ("TCJA") was signed into law, significantly impacting several sections of the Internal Revenue Code. ASC 740, Accounting for Income Taxes , requires companies to recognize the effect of tax law changes in the period of enactment even though the effective date for most provisions is for tax years beginning after December 31, 2017, or in the case of certain other provisions, January 1, 2018. Though certain key aspects of the TCJA are effective January 1, 2018 and have an immediate accounting effect, other significant provisions are not effective or may not result in accounting effects for September 30 fiscal year companies until October 1, 2018. Given the significance of the TCJA, the SEC staff issued Staff Accounting Bulletin No. 118 (SAB 118), which allows registrants to record provisional amounts during a one year “measurement period”. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared or analyzed. Among the significant changes to the U.S. Internal Revenue Code, the TCJA lowers the U.S. federal corporate income tax rate (“Federal Tax Rate”) from 35% to 21% effective January 1, 2018. The Company will compute its income tax expense for the September 30, 2018 fiscal year using a blended Federal Tax Rate of 24.5% . The 21% Federal Tax Rate will apply to fiscal years ending September 30, 2019 and each year thereafter. The Company has recorded provisional amounts for the effects of the TCJA where accounting is not complete, but a reasonable estimate has been determined. As of September 30, 2018, the company recorded a $20,587 benefit on the revaluation of deferred tax liabilities as a provisional amount for the re-measurement of deferred tax assets and liabilities, as well as an amount for deductible executive compensation expense, both of which have been reflected in the tax provision for the year ended September 30, 2018. The TCJA requires companies to pay a one-time transition tax on mandatory deemed repatriation of post-1986 undistributed foreign earnings and profits (“E&P”). The Company has recorded a provisional transition tax charge of $13,100 net of foreign tax credits. These have been included in the income tax provision for the year ended September 30, 2018. The Company will refine its calculation of the total post-1986 foreign E&P for any adjustments impacting its foreign subsidiaries and foreign tax credits. Under the TCJA, the Company will elect to pay the transition tax interest-free over eight years. The provisional amounts incorporate assumptions made based upon the Company’s current interpretation of the TCJA and may change as the Company receives additional clarification and implementation guidance. In accordance with SAB 118 adjustments recorded to the provisional amounts will be reflected within the measurement period ending December 31, 2018 and will be included in income from continuing operations and net income as an adjustment to tax expense. Income taxes have been based on the following components of Income before taxes from continuing operations: For the Years Ended September 30, 2018 2017 2016 Domestic $ 4,942 $ (1,339 ) $ 23,163 Non-U.S. 28,868 18,037 9,050 $ 33,810 $ 16,698 $ 32,213 Provision (benefit) for income taxes on income was comprised of the following from continuing operations: For the Years Ended September 30, 2018 2017 2016 Current $ 18,188 $ (3,426 ) $ 6,388 Deferred (17,633 ) 2,341 6,044 Total $ 555 $ (1,085 ) $ 12,432 U.S. Federal $ (12,714 ) $ (6,689 ) $ 4,358 State and local 5,175 3,307 3,287 Non-U.S. 8,094 2,297 4,787 Total provision $ 555 $ (1,085 ) $ 12,432 Griffon's income tax provision for the years ended September 30, 2018, 2017 and 2016 included a $1,299 , $4,440 and $2,193 benefit, respectively, from the early adoption of the new FASB accounting guidance which now requires excess tax benefits from vesting of equity awards to be recognized within income tax expense. Under this guidance all excess tax benefits (“windfalls”) and deficiencies (“shortfalls”) related to employee stock compensation are recognized within income tax expense. Under prior guidance windfalls were recognized to Additional Paid In Capital and shortfalls were only recognized to the extent they exceed the pool of windfall tax benefits. Griffon’s income tax provision included benefits of ($421) in 2018 , ($122) in 2017 , and ($2,172) in 2016 reflecting the reversal of previously recorded tax liabilities including the resolution of various tax audits and the closing of certain statutes for prior years’ tax returns. Differences between the effective income tax rate applied to Income and U.S. Federal income statutory rate from continuing operations were as follows: For the Years Ended September 30, 2018 2017 2016 U.S. Federal income tax provision (benefit) rate 24.5 % 35.0 % 35.0 % State and local taxes, net of Federal benefit 10.2 % 12.4 % 6.6 % Non-U.S. taxes - foreign permanent items and taxes 3.6 % (12.4 )% (1.6 )% Non-U.S. tax true-up — % (11.4 )% — % Change in domestic manufacturing deduction — % (5.8 )% — % Change in tax contingency reserves (0.6 )% 0.7 % (6.3 )% Impact of federal rate change on deferred tax balances (60.0 )% — % — % Repatriation of foreign earnings 61.6 % — % — % Change in valuation allowance 13.4 % (0.6 )% (0.6 )% Non-deductible/non-taxable items, net (2.4 )% 8.3 % 2.6 % Research and U.S. foreign tax credits (39.4 )% (3.6 )% 8.8 % Share based compensation (3.8 )% (26.6 )% (5.7 )% Other (5.5 )% (2.5 )% (0.2 )% Effective tax provision (benefit) rate 1.6 % (6.5 )% 38.6 % The tax effect of temporary differences that give rise to future deferred tax assets and liabilities are as follows: At September 30, 2018 2017 Deferred tax assets: Bad debt reserves $ 1,404 $ 2,509 Inventory reserves 7,709 7,615 Deferred compensation (equity compensation and defined benefit plans) 11,437 27,430 Compensation benefits 5,434 6,111 Insurance reserve 1,782 2,985 Restructuring reserve — 29 Warranty reserve 2,598 2,893 Net operating loss 10,593 37,383 Tax credits 6,379 1,866 Other reserves and accruals 5,433 7,658 52,769 96,479 Valuation allowance (8,520 ) (17,466 ) Total deferred tax assets 44,249 79,013 Deferred tax liabilities: Deferred income — (1,862 ) Goodwill and intangibles (44,402 ) (70,560 ) Property, plant and equipment (39,260 ) (51,488 ) Deferred gain on assets held for sale — (16,300 ) Other (1,086 ) (1,016 ) Total deferred tax liabilities (84,748 ) (141,226 ) Net deferred tax liabilities $ (40,499 ) $ (62,213 ) The decrease in the valuation allowance of $8,946 is primarily the result of the disposition of PPC and its related valuation allowance on accumulated Germany net operating losses. The deferred tax gain on assets held for sale results from the book versus tax outside basis difference and was removed concurrent with the sale of PPC. The components of the net deferred tax liability, by balance sheet account, were as follows: At September 30, 2018 2017 Other assets $ 61 $ 6 Assets of discontinued operations held for sale — 6,745 Other liabilities (42,689 ) (58,505 ) Liabilities of discontinued operations held for sale 872 (12,584 ) Liabilities of discontinued operations not held for sale 1,257 2,125 Net deferred liability $ (40,499 ) $ (62,213 ) At both September 30, 2018 and 2017 , Griffon has a policy election to indefinitely reinvest the undistributed earnings of foreign subsidiaries with operations outside the U.S. Griffon considers the earnings of these foreign subsidiaries to be indefinitely invested outside the U.S. on the basis of estimates that future domestic cash generation will be sufficient to meet future domestic cash needs. The majority of the amounts held outside the U.S. are generally utilized to support non U.S. liquidity needs in order to fund operations and growth of the foreign subsidiaries, and for funding of acquisitions. Griffon has not recorded deferred income taxes on the undistributed earnings of its non-U.S. subsidiaries because of management’s ability and intent to indefinitely reinvest such earnings outside the U.S. At September 30, 2018 , Griffon’s share of the undistributed earnings of the non-U.S. subsidiaries amounted to approximately $64,204 . It is not practicable to estimate the amount of deferred tax liability related to investments in these foreign subsidiaries. If a determination is made to repatriate some or all of these foreign earnings, the income tax provision would be adjusted in the period of that determination to accrue for the taxes payable on such earnings. At September 30, 2018 and 2017 , Griffon had loss carryforwards for U.S. tax purposes of $6,089 and $1,264 , respectively, and non-U.S. tax purposes of $7,319 and $7,941 , respectively. The U.S. losses expire beginning in 2033. The non-U.S. loss carryforwards are available for carryforward indefinitely. At September 30, 2018 and 2017 , Griffon had state and local loss carryforwards of $124,442 and $114,837 , respectively, which expire in varying amounts through 2038 . At September 30, 2018 and 2017 , Griffon had federal tax credit carryforwards of $5,740 and $1,762 , respectively, which expire beginning in 2028 . We believe it is more likely than not that the benefit from certain state net operating losses and federal tax credits will not be realized. In recognition of this risk, we have provided a valuation allowance as of September 30, 2018 and 2017 of $7,597 and $1,343 , respectively, on the deferred tax assets relating to these state net operating loss carryforwards and federal credits. If our assumptions change and we determine we will be able to realize these state net operating loss carryforwards or federal credits, the benefits relating to the reversal of the valuation allowance will be recognized as a reduction of income tax expense. If certain substantial changes in Griffon's ownership occur, there would be an annual limitation on the amount of carryforward(s) that can be utilized. Griffon files U.S. Federal, state and local tax returns, as well as applicable returns in Canada, Australia, Ireland and other non-U.S. jurisdictions. Griffon’s U.S. Federal income tax returns are no longer subject to income tax examination for years before 2013. Griffon's major U.S. state and other non-U.S. jurisdictions are no longer subject to income tax examinations for years before 2011. Various U.S. state and non-U.S. statutory tax audits are currently underway. The following is a roll forward of unrecognized tax benefits: Balance at September 30, 2016 $ 4,709 Additions based on tax positions related to the current year 177 Additions based on tax positions related to prior years 69 Reductions based on tax positions related to prior years (8 ) Lapse of Statutes (122 ) Balance at September 30, 2017 4,825 Additions based on tax positions related to the current year 152 Reductions based on tax positions related to prior years (253 ) Additions based on tax positions related to prior years 26 Lapse of Statutes (194 ) Settlements (37 ) Balance at September 30, 2018 $ 4,519 If recognized, the amount of potential tax benefits that would impact Griffon’s effective tax rate is $1,248 . Griffon recognizes potential accrued interest and penalties related to unrecognized tax benefits in income tax expense. At September 30, 2018 and 2017 , the combined amount of accrued interest and penalties related to tax positions taken or to be taken on Griffon’s tax returns and recorded as part of the reserves for uncertain tax positions was $122 and $174 , respectively. Griffon cannot reasonably estimate the extent to which existing liabilities for uncertain tax positions may increase or decrease within the next twelve months as a result of the progression of ongoing tax audits or other events. Griffon believes that it has adequately provided for all open tax years by tax jurisdiction.

STOCKHOLDERS' EQUITY AND EQUITY

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION	12 Months Ended
	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
STOCKHOLDERS’ EQUITY AND EQUITY COMPENSATION	STOCKHOLDERS’ EQUITY AND EQUITY COMPENSATION During 2018 , 2017 and 2016, the Company declared and paid cash dividends totaling $0.28 per share, $0.24 per share and $0.20 per share, respectively. In addition, on March 7, 2018, the Board of Directors declared a special cash dividend of $1.00 per share, totaling $38,073 and paid on April 16, 2018 to shareholders of record as of the close of business on March 29, 2018. The Company currently intends to pay dividends each quarter; however, payment of dividends is determined by the Board of Directors at its discretion based on various factors, and no assurance can be provided as to the payment of future dividends. Dividends paid on shares in the ESOP, including the special dividend, were used to offset ESOP loan payments and prepay principal and recorded as a reduction of debt service payments and compensation expense. A dividend payable was established for the holders of restricted shares; such dividends will be released upon vesting of the underlying restricted shares. On November 14, 2018, the Board of Directors declared a cash dividend of $0.0725 per share, payable on December 20, 2018 to shareholders of record as of the close of business on November 29, 2018. On January 29, 2016, shareholders approved the Griffon Corporation 2016 Equity Incentive Plan ("Incentive Plan") under which awards of performance shares, performance units, stock options, stock appreciation rights, restricted shares, restricted stock units, deferred shares and other stock-based awards may be granted. On January 31, 2018, shareholders approved Amendment No. 1 to the Incentive Plan pursuant which, among other things, added 1,000,000 shares to the Incentive Plan. Options granted under the Incentive Plan may be either “incentive stock options” or nonqualified stock options, generally expire ten years after the date of grant and are granted at an exercise price of not less than 100% of the fair market value at the date of grant. The maximum number of shares of common stock available for award under the Incentive Plan is 3,350,000 ( 600,000 of which may be issued as incentive stock options), plus (i) any shares reserved for issuance under the 2011 Equity Incentive Plan as of the effective date of the Incentive Plan, and (ii) any shares underlying awards outstanding on such effective date under the 2011 Incentive Plan that are canceled or forfeited. As of September 30, 2018 , 1,145,834 shares were available for grant. All grants outstanding under former equity plans will continue under their terms; no additional awards will be granted under such plans. Compensation expense for restricted stock and restricted stock units ("RSUs") is recognized ratably over the required service period based on the fair value of the grant, calculated as the number of shares (or RSUs) granted multiplied by the stock price on date of grant, and for performance shares (or performance RSUs), the likelihood of achieving the performance criteria. Compensation cost related to stock-based awards with graded vesting, generally over a period of three to four years , is recognized using the straight-line attribution method and recorded within Selling, general and administrative expenses. The following table summarizes the Company’s compensation expense relating to all stock-based incentive plans: For the Years Ended September 30, 2018 2017 2016 Pre-tax compensation expense $ 10,078 $ 8,090 $ 10,136 Tax benefit (2,469 ) (2,836 ) (3,553 ) Total stock-based compensation expense, net of tax $ 7,609 $ 5,254 $ 6,583 As of ended September 30, 2018 and 2017, a stock option to purchase 350,000 shares was outstanding and exercisable at a weighted average exercise price of $20.00 . This option expired on October 1, 2018. A summary of restricted stock activity, inclusive of restricted stock units, for the year ended September 30, 2018 , is as follows: Shares Weighted Average Grant- Date Fair Value Unvested at September 30, 2017 2,255,796 $ 13.65 Granted 1,343,929 17.30 Vested (536,958 ) 20.89 Forfeited (212,939 ) 20.91 Unvested at September 30, 2018 2,849,828 14.89 The fair value of restricted stock which vested during the year ended September 30, 2018, 2017, and 2016 was $11,216 , $29,508 and $23,965 , respectively. Unrecognized compensation expense related to non-vested shares of restricted stock was $22,869 at September 30, 2018 and will be recognized over a weighted average vesting period of 2.3 years. At September 30, 2018 , a total of approximately 4,345,662 shares of Griffon’s authorized Common Stock were reserved for issuance in connection with stock compensation plans. During 2018, Griffon granted 1,343,929 shares of restricted stock and restricted stock units. This included 815,929 shares of restricted stock and restricted stock units, subject to certain performance conditions, with vesting periods of three years , with a total fair value of $16,238 , or a weighted average fair value of $19.90 per share. Also, this included 528,000 shares of restricted stock granted to two senior executives with a vesting period of four years and a two year post-vesting holding period, subject to the achievement of certain absolute and relative performance conditions relating to the price of Griffon's common stock. The Monte Carlo Simulation model was chosen to value the two senior executive awards; the total fair value of these restricted shares is approximately $7,008 , or a weighted average fair value of $13.27 . So long as the minimum performance condition is attained, the amount of shares that can vest will range from 384,000 to 528,000 . On each of August 3, 2016 and August 1, 2018, Griffon’s Board of Directors authorized the repurchase of up to $50,000 of Griffon’s outstanding common stock. Under these share repurchase programs, the Company may purchase shares of its common stock, depending upon market conditions, in open market or privately negotiated transactions, including pursuant to a 10b5-1 plan. Shares repurchased are recorded at cost. During 2018, Griffon purchased 2,088,739 shares of common stock under these repurchase programs, for a total of $41,110 or $19.68 per share. At September 30, 2018, an aggregate of $58,327 remains under Griffon's Board authorized repurchase authorizations. In addition to the repurchases under Board authorized programs, during 2018 , 199,978 shares, with a market value of $4,495 , or $22.48 per share, were withheld to settle employee taxes due upon the vesting of restricted stock. On December 10, 2013 Griffon repurchased 4,444,444 shares of common stock from GS Direct in a private transaction at a per share price of $11.25 , an approximate 9.2% discount to the stock’s closing price on November 12, 2013, the day before announcement of the transaction. On June 19, 2018, GS Direct completed an underwritten secondary offering to sell 5,583,375 shares of Griffon's common stock, inclusive of the underwriters’ 30-day option to purchase additional shares. Following the closing of the offering, GS Direct no longer owns any shares of Griffon. GS Direct's initial 10,000,000 share investment was in 2008. On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000 , if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858 , or 1,954,993 shares of common stock issued from treasury. During the year ended September 30, 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized.

COMMITMENTS AND CONTINGENT LIAB

COMMITMENTS AND CONTINGENT LIABILITIES	12 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENT LIABILITIES	COMMITMENTS AND CONTINGENT LIABILITIES Operating leases Griffon rents real property and equipment under operating leases expiring at various dates. Most of the real property leases have escalation clauses related to increases in real property taxes. Rent expense for all operating leases totaled approximately $35,726 , $26,297 and $26,180 in 2018 , 2017 and 2016, respectively. Aggregate future minimum lease payments for operating leases at September 30, 2018 are $32,189 in 2019 , $26,365 in 2020 , $16,600 in 2021 , $10,811 in 2022 , $6,082 in 2023 and $12,135 thereafter. Purchase Commitments Purchase obligations are generally for the purchase of goods and services in the ordinary course of business. Griffon uses blanket purchase orders to communicate expected requirements to certain vendors. Purchase obligations reflect those purchase orders where the commitment is considered to be firm. Purchase obligations that extend beyond 2017 are principally related to long-term contracts received from customers of Telephonics. Aggregate future minimum purchase obligations at September 30, 2018 are $226,026 in 2019, $5,569 in 2020, $2 in 2021, $1 in 2022 and $1,470 in 2023. Legal and environmental Department of Environmental Conservation of New York State (“DEC”), with ISC Properties, Inc. Lightron Corporation (“Lightron”), a wholly-owned subsidiary of Griffon, once conducted operations at a location in Peekskill in the Town of Cortlandt, New York (the “Peekskill Site”) owned by ISC Properties, Inc. (“ISC”), a wholly-owned subsidiary of Griffon. ISC sold the Peekskill Site in November 1982. Subsequently, ISC was advised by the DEC that random sampling at the Peekskill Site and in a creek near the Peekskill Site indicated concentrations of solvents and other chemicals common to Lightron’s prior plating operations. ISC then entered into a consent order with the DEC in 1996 (the “Consent Order”) to perform a remedial investigation and prepare a feasibility study. After completing the initial remedial investigation pursuant to the Consent Order, ISC was required by the DEC, and did accordingly conduct over the next several years, supplemental remedial investigations, including soil vapor investigations, under the Consent Order. In April 2009, the DEC advised ISC’s representatives that both the DEC and the New York State Department of Health had reviewed and accepted an August 2007 Remedial Investigation Report and an Additional Data Collection Summary Report dated January 30, 2009. With the acceptance of these reports, ISC completed the remedial investigation required under the Consent Order and was authorized, accordingly, by the DEC to conduct the Feasibility Study required by the Consent Order. Pursuant to the requirements of the Consent Order and its obligations thereunder, ISC, without acknowledging any responsibility to perform any remediation at the Site, submitted to the DEC in August 2009, a draft feasibility study which recommended for the soil, groundwater and sediment media, remediation alternatives having a current net capital cost value, in the aggregate, of approximately $5,000 . In February 2011, DEC advised ISC it has accepted and approved the feasibility study. Accordingly, ISC has no further obligations under the consent order. Upon acceptance of the feasibility study, DEC issued a Proposed Remedial Action Plan (“PRAP”) that sets forth the proposed remedy for the site. The PRAP accepted the recommendation contained in the feasibility study for remediation of the soil and groundwater media, but selected a different remediation alternative for the sediment medium. After receiving public comments on the PRAP, the DEC issued a Record of Decision (“ROD”) in June 2011 that set forth the specific remedies selected and responded to public comments. The remedies selected by the DEC in the ROD are the same remedies as those set forth in the PRAP. At the time of adoption of the ROD, the approximate cost of the remedy proposed by DEC in the PRAP was approximately $10,000 . It is now expected that DEC will enter into negotiations with potentially responsible parties to request they undertake performance of the remedies selected in the ROD, and if such parties do not agree to implement such remedies, then the State of New York may use State Superfund money to remediate the Peekskill site and seek recovery of costs from such parties. Griffon does not acknowledge any responsibility to perform any remediation at the Peekskill Site. Improper Advertisement Claim involving Union Tools ® Products. Beginning in December 2004, a customer of AMES had been named in various litigation matters relating to certain Union Tools products. The plaintiffs in those litigation matters asserted causes of action against the customer of AMES for improper advertisement to end consumers. The allegations suggested that advertisements led the consumers to believe that Union Tools’ hand tools were wholly manufactured within boundaries of the United States. The complaints asserted various causes of action against the customer of AMES under federal and state law, including common law fraud. At some point, the customer may seek indemnity (including recovery of its legal fees and costs) against AMES for an unspecified amount. Presently, AMES cannot estimate the amount of loss, if any, if the customer were to seek legal recourse against AMES. Union Fork and Hoe, Frankfort, NY site. The former Union Fork and Hoe property in Frankfort, NY was acquired by Ames in 2006 as part of a larger acquisition, and has historic site contamination involving chlorinated solvents, petroleum hydrocarbons and metals. AMES has entered into an Order on Consent with the New York State Department of Environmental Conservation. While the Order is without admission or finding of liability or acknowledgment that there has been a release of hazardous substances at the site, AMES is required to perform a remedial investigation of certain portions of the property and to recommend a remediation option. At the conclusion of the remediation phase to the satisfaction of the DEC, the DEC will issue a Certificate of Completion. AMES has performed significant investigative and remedial activities in the last few years under work plans approved by the DEC, and the DEC has approved the final remedial investigation and feasibility study reports. AMES’ recommended remedial option of excavation and offsite disposal of lead contaminated soils, capping of other areas of the site impacted by other metals and performing limited groundwater monitoring was accepted by the DEC in a Record of Decision issued March 1, 2018. The Company has submitted a final design and implementation workplan to the State of New York and is awaiting approval. Implementation of the selected remedial alternative is expected to be completed in 2019. AMES has a number of defenses to liability in this matter, including its rights under a previous Consent Judgment entered into between the DEC and a predecessor of AMES relating to the site. U.S. Government investigations and claims Defense contracts and subcontracts, including Griffon’s contracts and subcontracts, are subject to audit and review by various agencies and instrumentalities of the United States government, including among others, the Defense Contract Audit Agency, the Defense Criminal Investigative Service, and the Department of Justice which has responsibility for asserting claims on behalf of the US government. In general, departments and agencies of the US Government have the authority to investigate various transactions and operations of Griffon, and the results of such investigations may lead to administrative, civil or criminal proceedings, the ultimate outcome of which could be fines, penalties, repayments or compensatory or treble damages. US Government regulations provide that certain findings against a contractor may lead to suspension or debarment from future US Government contracts or the loss of export privileges for a company or an operating division or subdivision. Suspension or debarment could have a material adverse effect on Telephonics because of its reliance on government contracts. General legal Griffon is subject to various laws and regulations relating to the protection of the environment and is a party to legal proceedings arising in the ordinary course of business. Management believes, based on facts presently known to it, that the resolution of the matters above and such other matters will not have a material adverse effect on Griffon’s consolidated financial position, results of operations or cash flows.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic and diluted EPS for the years ended September 30, 2018 , 2017 and 2016 were determined using the following information (in thousands): 2018 2017 2016 Weighted average shares outstanding - basic 41,005 41,005 41,074 Incremental shares from stock based compensation 1,417 1,642 2,326 Convertible debt due 2017 — 364 709 Weighted average shares outstanding - diluted 42,422 43,011 44,109 Anti-dilutive options excluded from diluted EPS computation — — 6 Shares of the ESOP that have been allocated to employee accounts are treated as outstanding in determining earnings per share.

RELATED PARTIES

RELATED PARTIES	12 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
RELATED PARTIES	RELATED PARTIES On May 10, 2017, Griffon entered into an engagement letter with Goldman Sachs & Co. LLC (“Goldman Sachs”) pursuant to which Goldman Sachs agreed to act as Griffon’s financial advisor in connection with the acquisition of ClosetMaid. Griffon subsequently paid a customary financial advisory fee to Goldman Sachs under the terms of this engagement letter following consummation of the acquisition. On September 5, 2017, Griffon entered into an engagement letter with Goldman Sachs pursuant to which Goldman Sachs agreed to act as Griffon’s financial advisor in connection with the exploration of strategic alternatives for Clopay Plastics. On November 15, 2017, Griffon signed an agreement to sell Clopay Plastics for approximately $475,000 to Berry. Under the terms of the engagement letter, upon the closing of the transaction a customary advisory fee will be payable by Griffon to Goldman Sachs. Goldman Sachs acted as a joint lead manager and as an initial purchaser in connection with Griffon’s add-on offering of $275,000 aggregate principal amount of 5.25% senior notes due 2022 that closed on October 2, 2017, and received a customary fee upon closing of the offering. On June 19, 2018, GS Direct completed an underwritten secondary offering to sell 5,583,375 shares of Griffon's common stock, inclusive of the underwriters' 30-day option to purchase additional shares. Following the closing of the offering, GS Direct no longer owns any shares of Griffon. GS Direct's initial 10,000,000 share investment was in 2008.

QUARTERLY FINANCIAL INFORMATION

QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	12 Months Ended
	Sep. 30, 2018
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIAL INFORMATION (UNAUDITED)	QUARTERLY FINANCIAL INFORMATION (UNAUDITED) Quarterly results of continuing operations for the years ended September 30, 2018 and 2017 were as follows: Quarter ended Revenue Gross Profit Income from continuing operations Per Share - Basic Per Share - Diluted 2018 December 31, 2017 $ 437,303 $ 120,844 $ 22,831 $ 0.54 $ 0.53 March 31, 2018 478,560 121,473 1,951 0.05 0.05 June 30, 2018 516,550 138,792 7,442 0.18 0.18 September 30, 2018 545,505 148,451 1,031 0.03 0.02 $ 1,977,918 $ 529,560 $ 33,255 $ 0.81 $ 0.78 2017 December 31, 2016 $ 352,277 $ 96,744 $ 7,044 $ 0.18 $ 0.17 March 31, 2017 383,807 98,869 1,950 0.05 0.05 June 30, 2017 358,114 97,984 4,452 0.11 0.10 September 30, 2017 430,799 114,519 4,337 0.10 0.10 $ 1,524,997 $ 408,116 $ 17,783 $ 0.43 $ 0.41 Notes to Quarterly Financial Information (unaudited): • Earnings (loss) per share are computed independently for each quarter and year presented; as such the sum of the quarters may not be equal to the full year amounts. • 2018 Net income, and the related per share earnings, included, net of tax, acquisition related costs of $2,348 , $378 , $2,320 for the first, second and third quarters, respectively, a cost of life insurance benefit of $248 for the first quarter, special dividend ESOP charges of $2,125 for the third quarter, and secondary equity offering costs of $795 for the third quarter. • 2017 Net income, and the related per share earnings, included, net of tax, acquisition related costs of $6,145 and contract settlement charges of $3,300 .

REPORTABLE SEGMENTS

REPORTABLE SEGMENTS	12 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
REPORTABLE SEGMENTS	REPORTABLE SEGMENTS Griffon’s reportable segments from continuing operations are as follows: • HBP is a global provider of long-handled tools and landscaping products for homeowners and professionals; a leading North American manufacturer and marketer of wood and wire closet organization, general living storage and wire garage storage products to home center retail chains, mass merchandisers, and direct-to builder professional installers; a leading manufacturer and marketer of residential and commercial garage doors to professional dealers and to some of the largest home center retail chains in North America; as well as a leading U.S. manufacturer and marketer of rolling steel door and grille products designed for commercial, industrial, institutional, and retail use. • Defense Electronics segment consists of Telephonics a globally recognized leading provider of highly sophisticated intelligence, surveillance and communications solutions for defense, aerospace and commercial customers. On November 16, 2017, Griffon announced it entered into a definitive agreement to sell PPC and on February 6, 2018, completed the sale to Berry for approximately $475,000 . As a result, Griffon classified the results of operations of the PPC business as discontinued operations in the Consolidated Statements of Operations for all periods presented and classified the related assets and liabilities associated with the discontinued operations in the consolidated balance sheets. All results and information presented exclude PPC unless otherwise noted. See Note 6, Discontinued Operations to the Notes of the Financial Statements. On October 2, 2017, Griffon acquired ClosetMaid. ClosetMaid, founded in 1965, is a leading North American manufacturer and marketer of wood and wire closet organization, general living storage and wire garage storage products and sells to some of the largest home center retail chains, mass merchandisers, and direct-to-builder professional installers in North America. The accounts of ClosetMaid, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, are included in the Company’s consolidated financial statements from the date of acquisition. On June 4, 2018, CBP acquired CornellCookson, a leading US manufacturer and marketer of rolling steel door and grille products designed for commercial, industrial, institutional and retail use. The accounts, affected for preliminary adjustments to reflect fair market values assigned to assets purchased and liabilities assumed, and results of operations of CornellCookson, are included in the Company’s consolidated financial statements from the date of acquisition. Information on Griffon’s reportable segments from continuing operations is as follows: For the Years Ended September 30, REVENUE 2018 2017 2016 Home & Building Products: AMES $ 953,612 $ 545,269 $ 513,973 CBP 697,969 568,001 527,370 Home & Building Products 1,651,581 1,113,270 1,041,343 Defense Electronics 326,337 $ 411,727 $ 435,692 Total consolidated net sales $ 1,977,918 $ 1,524,997 $ 1,477,035 For the Years Ended September 30, INCOME BEFORE TAXES FROM CONTINUING OPERATIONS 2018 2017 2016 Segment operating profit: Home & Building Products $ 130,487 $ 89,495 $ 79,682 Defense Electronics 25,262 29,943 42,801 Segment operating profit from continuing operations 155,749 119,438 122,483 Net interest expense (63,871 ) (51,449 ) (49,877 ) Unallocated amounts (45,812 ) (42,398 ) (40,393 ) Acquisition costs (5,217 ) (8,893 ) — Special dividend charges (3,220 ) — — Cost of life insurance benefit (2,614 ) — — Secondary equity offering costs (1,205 ) — — Income before taxes from continuing operations $ 33,810 $ 16,698 $ 32,213 Griffon evaluates performance and allocates resources based on each segment's operating results from continuing operations before interest income and expense, income taxes, depreciation and amortization, unallocated amounts (mainly corporate overhead), restructuring charges, loss on debt extinguishment and acquisition related expenses, as well as other items that may affect comparability, as applicable (“Segment adjusted EBITDA”, a non-GAAP measure). The following table provides a reconciliation of Segment adjusted EBITDA to Income before taxes and discontinued operations: For the Years Ended September 30, 2018 2017 2016 Segment adjusted EBITDA: Home & Building Products $ 177,400 $ 126,766 $ 114,949 Defense Electronics 36,063 45,931 53,385 Total Segment adjusted EBITDA from continuing operations 213,463 172,697 168,334 Net interest expense (63,871 ) (51,449 ) (49,877 ) Segment depreciation and amortization (55,334 ) (47,398 ) (45,851 ) Unallocated amounts (45,812 ) (42,398 ) (40,393 ) Acquisition costs (7,597 ) (9,617 ) — Special dividend charges (3,220 ) — — Cost of life insurance benefit (2,614 ) — — Secondary equity offering costs (1,205 ) — — Contract settlement charges — (5,137 ) — Income before taxes from continuing operations $ 33,810 $ 16,698 $ 32,213 For the Years Ended September 30, DEPRECIATION and AMORTIZATION 2018 2017 2016 Segment: Home & Building Products $ 44,533 $ 36,547 $ 35,267 Defense Electronics 10,801 10,851 10,584 Total segment depreciation and amortization 55,334 47,398 45,851 Corporate 469 480 491 Total consolidated depreciation and amortization $ 55,803 $ 47,878 $ 46,342 CAPITAL EXPENDITURES Segment: Home & Building Products $ 36,587 $ 24,476 $ 49,351 Defense Electronics 10,941 8,204 9,007 Total segment 47,528 32,680 58,358 Corporate 2,610 2,257 918 Total consolidated capital expenditures $ 50,138 $ 34,937 $ 59,276 ASSETS At September 30, 2018 At September 30, 2017 At September 30, 2016 Segment assets: Home & Building Products $ 1,631,631 $ 1,084,103 $ 1,020,297 Defense Electronics 346,907 343,445 334,631 Total segment assets 1,978,538 1,427,548 1,354,928 Corporate 103,112 71,980 62,257 Total continuing assets 2,081,650 1,499,528 1,417,185 Assets of discontinued operations 3,240 374,013 364,911 Consolidated total $ 2,084,890 $ 1,873,541 $ 1,782,096 Segment information by geographic region was as follows: For the Years Ended September 30, REVENUE BY GEOGRAPHIC AREA - DESTINATION 2018 2017 2016 United States $ 1,521,187 $ 1,164,958 $ 1,149,448 Europe 102,814 67,048 68,604 Canada 123,341 106,080 102,333 Australia 166,980 124,757 106,780 All other countries 63,596 62,154 49,870 Consolidated revenue $ 1,977,918 $ 1,524,997 $ 1,477,035 For the Years Ended September 30, LONG-LIVED ASSETS BY GEOGRAPHIC AREA 2018 2017 2016 United States $ 612,294 $ 358,795 $ 370,332 Canada 33,884 36,383 35,984 Australia 33,288 35,917 26,196 United Kingdom 24,892 4,144 — Mexico 7,017 — — All other countries 1,976 2,023 2,342 Consolidated long-lived assets, net $ 713,351 $ 437,262 $ 434,854 As a percentage of consolidated revenue from continuing operations, HBP sales to Home Depot approximated 19% in 2018 and 17% in both 2017 and 2016 , respectively; and Telephonics aggregate sales to the United States Government and its agencies approximated 10% in 2018 , 18% in 2017 and 21% in 2016 .

OTHER INCOME (EXPENSE)

OTHER INCOME (EXPENSE)	12 Months Ended
	Sep. 30, 2018
Other Income and Expenses [Abstract]
OTHER INCOME (EXPENSE)	OTHER INCOME (EXPENSE) Other income (expense) included ($200) , ($723) and $(550) for the years ended September 30, 2018 , 2017 and 2016, respectively, of currency exchange gains (losses) in connection with the translation of receivables and payables denominated in currencies other than the functional currencies of Griffon and its subsidiaries, as well as $1,184 , $53 and $316 , respectively, of investment income.

OTHER COMPREHENSIVE INCOME (LOS

OTHER COMPREHENSIVE INCOME (LOSS)	12 Months Ended
	Sep. 30, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
OTHER COMPREHENSIVE INCOME (LOSS)	OTHER COMPREHENSIVE INCOME (LOSS) The amounts recognized in other comprehensive income (loss) were as follows: Years Ended September 30, 2018 2017 2016 Pre-tax Tax Net of tax Pre-tax Tax Net of tax Pre-tax Tax Net of tax Foreign currency translation adjustments $ 9,403 $ — $ 9,403 $ 10,667 $ — $ 10,667 $ 17,284 $ — $ 17,284 Pension and other defined benefit plans 24,081 (7,700 ) 16,381 14,160 (4,957 ) 9,203 (8,694 ) 3,043 (5,651 ) Cash flow hedge 900 (315 ) 585 1,370 (480 ) 890 (2,593 ) 907 (1,686 ) Total other comprehensive income (loss) $ 34,384 $ (8,015 ) $ 26,369 $ 26,197 $ (5,437 ) $ 20,760 $ 5,997 $ 3,950 $ 9,947 The components of Accumulated other comprehensive income (loss) are as follows: At September 30, 2018 2017 Foreign currency translation $ (22,824 ) $ (32,227 ) Pension and other defined benefit plans (11,759 ) (28,140 ) Cash flow hedge 471 (114 ) $ (34,112 ) $ (60,481 ) Total comprehensive income (loss) were as follows: For the Years Ended September 30, 2018 2017 2016 Net income (loss) $ 125,678 $ 14,912 $ 30,010 Other comprehensive income (loss), net of taxes 26,369 20,760 9,947 Comprehensive income (loss) $ 152,047 $ 35,672 $ 39,957 Amounts reclassified from accumulated other comprehensive income (loss) to income (loss) were as follows: For the Years Ended September 30, Gain (Loss) 2018 2017 2016 Pension amortization $ (1,397 ) $ (3,343 ) $ (2,375 ) Cash flow hedges 657 (1,458 ) (752 ) Total before tax (740 ) (4,801 ) (3,127 ) Tax 155 1,680 1,094 Net of tax $ (585 ) $ (3,121 ) $ (2,033 )

CONSOLIDATING GUARANTOR AND NON

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION	12 Months Ended
	Sep. 30, 2018
Consolidating Guarantor And Non Guarantor Financial Information [Abstract]
CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION	CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION Griffon’s Senior Notes are fully and unconditionally guaranteed, jointly and severally, on a senior secured basis by the domestic assets of Clopay Building Products Company, Inc., Telephonics Corporation, The AMES Companies, Inc., ATT Southern, Inc., Clopay Ames True Temper Holding, Corp., ClosetMaid, LLC, CornellCookson, LLC and Cornell Real Estate Holdings, LLC. all of which are indirectly 100% owned by Griffon. In accordance with Rule 3-10 of Regulation S-X promulgated under the Securities Act of 1933, presented below are condensed consolidating financial information as of September 30, 2018 and 2017, and for the years ended September 30, 2018 , 2017 and 2016. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor companies or non-guarantor companies operated as independent entities. The guarantor companies and the non-guarantor companies include the consolidated financial results of their wholly owned subsidiaries accounted for under the equity method. The indenture relating to the Senior Notes (the “Indenture”) contains terms providing that, under certain limited circumstances, a guarantor will be released from its obligations to guarantee the Senior Notes. These circumstances include (i) a sale of at least a majority of the stock, or all or substantially all the assets, of the subsidiary guarantor as permitted by the Indenture; (ii) a public equity offering of a subsidiary guarantor that qualifies as a “Minority Business” as defined in the Indenture (generally, a business the EBITDA of which constitutes less than 50% of the segment adjusted EBITDA of the Company for the most recently ended four fiscal quarters), and that meets certain other specified conditions as set forth in the Indenture; (iii) the designation of a guarantor as an “unrestricted subsidiary” as defined in the Indenture, in compliance with the terms of the Indenture; (iv) Griffon exercising its right to defease the Senior Notes, or to otherwise discharge its obligations under the Indenture, in each case in accordance with the terms of the Indenture; and (v) upon obtaining the requisite consent of the holders of the Senior Notes. CONDENSED CONSOLIDATING BALANCE SHEETS At September 30, 2018 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CURRENT ASSETS Cash and equivalents $ 15,976 $ 16,353 $ 37,429 $ — $ 69,758 Accounts receivable, net of allowances — 234,885 69,729 (24,105 ) 280,509 Contract costs and recognized income not yet billed, net of progress payments — 121,393 410 — 121,803 Inventories — 332,067 66,373 (81 ) 398,359 Prepaid and other current assets 12,179 21,313 6,168 2,461 42,121 Assets of discontinued operations not held for sale — — 324 — 324 Total Current Assets 28,155 726,011 180,433 (21,725 ) 912,874 PROPERTY, PLANT AND EQUIPMENT, net 936 299,920 41,636 — 342,492 GOODWILL 6,646 361,507 71,242 — 439,395 INTANGIBLE ASSETS, net 93 293,093 77,672 — 370,858 INTERCOMPANY RECEIVABLE 56,396 314,394 (121,445 ) (249,345 ) — EQUITY INVESTMENTS IN SUBSIDIARIES 1,528,932 968,330 3,347,894 (5,845,156 ) — OTHER ASSETS 8,651 15,942 374 (8,612 ) 16,355 ASSETS OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,916 — 2,916 Total Assets $ 1,629,809 $ 2,979,197 $ 3,600,722 $ (6,124,838 ) $ 2,084,890 CURRENT LIABILITIES Notes payable and current portion of long-term debt $ 2,276 $ 3,398 $ 7,337 $ — $ 13,011 Accounts payable and accrued liabilities 26,639 303,154 59,531 (16,474 ) 372,850 Liabilities of discontinued operations not held for sale — (22,327 ) 29,537 — 7,210 Total Current Liabilities 28,915 284,225 96,405 (16,474 ) 393,071 LONG-TERM DEBT, net 1,044,071 6,110 57,890 — 1,108,071 INTERCOMPANY PAYABLES 66,058 (77,760 ) 263,227 (251,525 ) — OTHER LIABILITIES 16,374 73,391 20,592 (3,647 ) 106,710 LIABILITIES OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,647 — 2,647 Total Liabilities 1,155,418 285,966 440,761 (271,646 ) 1,610,499 SHAREHOLDERS’ EQUITY 474,391 2,693,231 3,159,961 (5,853,192 ) 474,391 Total Liabilities and Shareholders’ Equity $ 1,629,809 $ 2,979,197 $ 3,600,722 $ (6,124,838 ) $ 2,084,890 CONDENSED CONSOLIDATING BALANCE SHEETS At September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CURRENT ASSETS Cash and equivalents 3,240 8,066 36,375 — 47,681 Accounts receivable, net of allowances — 168,731 59,929 (20,431 ) 208,229 Contract costs and recognized income not yet billed, net of progress payments — 131,383 279 — 131,662 Inventories, net — 246,605 52,759 73 299,437 Prepaid and other current assets 21,131 15,854 3,002 80 40,067 Assets of discontinued operations held for sale — 168,306 202,418 — 370,724 Assets of discontinued operations not held for sale — — 329 — 329 Total Current Assets 24,371 738,945 355,091 (20,278 ) 1,098,129 PROPERTY, PLANT AND EQUIPMENT, net 645 200,362 31,128 — 232,135 GOODWILL — 280,797 38,342 — 319,139 INTANGIBLE ASSETS, net 93 143,415 61,619 — 205,127 INTERCOMPANY RECEIVABLE 552,017 757,608 915,551 (2,225,176 ) — EQUITY INVESTMENTS IN SUBSIDIARIES 863,149 877,641 1,613,891 (3,354,681 ) — OTHER ASSETS 12,171 12,054 (1,002 ) (7,172 ) 16,051 ASSETS OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,960 — 2,960 Total Assets 1,452,446 3,010,822 3,017,580 (5,607,307 ) 1,873,541 CURRENT LIABILITIES Notes payable and current portion of long-term debt 2,854 1,471 6,753 — 11,078 Accounts payable and accrued liabilities 14,683 199,784 46,111 6,631 267,209 Liabilities of discontinued operations held for sale — 47,426 37,024 — 84,450 Liabilities of discontinued operations — — 8,342 — 8,342 Total Current Liabilities 17,537 248,681 98,230 6,631 371,079 LONG-TERM DEBT, net 903,609 6,044 58,427 — 968,080 INTERCOMPANY PAYABLES 84,068 1,259,413 854,518 (2,197,999 ) — OTHER LIABILITIES 48,424 76,036 14,135 (6,058 ) 132,537 LIABILITIES OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 3,037 — 3,037 Total Liabilities 1,053,638 1,590,174 1,028,347 (2,197,426 ) 1,474,733 SHAREHOLDERS’ EQUITY 398,808 1,420,648 1,989,233 (3,409,881 ) 398,808 Total Liabilities and Shareholders’ Equity 1,452,446 3,010,822 3,017,580 (5,607,307 ) 1,873,541 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) For the Year Ended September 30, 2018 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,638,792 $ 367,149 $ (28,023 ) $ 1,977,918 Cost of goods and services — 1,232,019 245,687 (29,348 ) 1,448,358 Gross profit — 406,773 121,462 1,325 529,560 Selling, general and administrative expenses 38,691 303,856 90,933 (370 ) 433,110 Income (loss) from operations (38,691 ) 102,917 30,529 1,695 96,450 Other income (expense) Interest income (expense), net (23,911 ) (31,913 ) (8,047 ) — (63,871 ) Other, net (6,515 ) 120,670 (111,187 ) (1,737 ) 1,231 Total other income (expense) (30,426 ) 88,757 (119,234 ) (1,737 ) (62,640 ) Income (loss) before taxes (69,117 ) 191,674 (88,705 ) (42 ) 33,810 Provision (benefit) for income taxes (17,692 ) 9,546 8,743 (42 ) 555 Income (loss) before equity in net income of subsidiaries (51,425 ) 182,128 (97,448 ) — 33,255 Equity in net income (loss) of subsidiaries 177,103 (151,864 ) 182,128 (207,367 ) — Income (loss) from continuing operations 125,678 30,264 84,680 (207,367 ) 33,255 Income (loss) from operations of discontinued businesses — 119,981 — — 119,981 Provision (benefit) from income taxes — 27,558 — — 27,558 Income (loss) from discontinued operations — 92,423 — — 92,423 Net Income (loss) $ 125,678 $ 122,687 $ 84,680 $ (207,367 ) $ 125,678 Comprehensive income (loss) $ 152,047 $ 143,936 $ 81,389 $ (225,325 ) $ 152,047 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) For the Year Ended September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,284,189 $ 270,520 $ (29,712 ) $ 1,524,997 Cost of goods and services — 966,293 181,634 (31,046 ) 1,116,881 Gross profit — 317,896 88,886 1,334 408,116 Selling, general and administrative expenses 42,273 232,720 64,466 (370 ) 339,089 Restructuring and other related charges — — — — — Total operating expenses 42,273 232,720 64,466 (370 ) 339,089 Income (loss) from operations (42,273 ) 85,176 24,420 1,704 69,027 Other income (expense) Interest income (expense), net (13,804 ) (24,242 ) (13,403 ) — (51,449 ) Other, net 59 1,395 (630 ) (1,704 ) (880 ) Total other income (expense) (13,745 ) (22,847 ) (14,033 ) (1,704 ) (52,329 ) Income (loss) before taxes from continuing operations (56,018 ) 62,329 10,387 — 16,698 Provision (benefit) for income taxes (11,338 ) 24,560 (14,307 ) — (1,085 ) Income (loss) before equity in net income of subsidiaries (44,680 ) 37,769 24,694 — 17,783 Equity in net income (loss) of subsidiaries 59,592 (25,231 ) 37,770 (72,131 ) — Income (loss) from continuing operations 14,912 12,538 62,464 (72,131 ) 17,783 Income from operations of discontinued businesses — 16,827 5,449 — 22,276 Provision (benefit) from income taxes — 4,476 20,671 — 25,147 Loss from discontinued operations — 12,351 (15,222 ) — (2,871 ) Net income (loss) $ 14,912 $ 24,889 $ 47,242 $ (72,131 ) $ 14,912 Comprehensive income (loss) $ 35,672 $ 35,575 $ 38,337 $ (73,912 ) $ 35,672 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) For the Year Ended September 30, 2016 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,277,241 $ 228,350 $ (28,556 ) $ 1,477,035 Cost of goods and services — 952,296 154,181 (30,135 ) 1,076,342 Gross profit — 324,945 74,169 1,579 400,693 Selling, general and administrative expenses 26,427 228,961 63,335 (370 ) 318,353 Restructuring and other related charges — 1,299 (1,299 ) — — Total operating expenses 26,427 230,260 62,036 (370 ) 318,353 Income (loss) from operations (26,427 ) 94,685 12,133 1,949 82,340 Other income (expense) Interest income (expense), net (12,549 ) (24,050 ) (13,278 ) — (49,877 ) Other, net 337 1,862 (500 ) (1,949 ) (250 ) Total other income (expense) (12,212 ) (22,188 ) (13,778 ) (1,949 ) (50,127 ) Income (loss) before taxes (38,639 ) 72,497 (1,645 ) — 32,213 Provision (benefit) for income taxes 4,964 29,445 (21,977 ) — 12,432 Income (loss) before equity in net income of subsidiaries (43,603 ) 43,052 20,332 — 19,781 Equity in net income (loss) of subsidiaries 73,613 (2,858 ) 43,052 (113,807 ) — Income (loss) from continuing operations $ 30,010 $ 40,194 $ 63,384 $ (113,807 ) $ 19,781 Income from operations of discontinued businesses — 15,625 5,327 — 20,952 Provision (benefit) from income taxes — 4,720 6,003 — 10,723 Income (loss) from discontinued operations — 10,905 (676 ) — 10,229 Net income (loss) $ 30,010 $ 51,099 $ 62,708 $ (113,807 ) $ 30,010 Comprehensive income (loss) $ 39,957 $ 44,391 $ 90,560 $ (134,951 ) $ 39,957 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2018 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 125,678 $ 122,687 $ 84,680 $ (207,367 ) $ 125,678 Net (income) loss from discontinued operations — (92,423 ) — — (92,423 ) Net cash provided by (used in) operating activities 389,671 (405,174 ) 108,981 (27,032 ) 66,446 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (544 ) (41,531 ) (8,063 ) — (50,138 ) Acquired business, net of cash acquired (368,936 ) (4,843 ) (57,153 ) — (430,932 ) Intercompany distributions — — — — — Proceeds from sale of business — 474,727 — — 474,727 Proceeds from sale of assets — 62 601 — 663 Net cash provided by (used in) investing activities (369,480 ) 428,415 (64,615 ) — (5,680 ) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from issuance of common stock — — — — — Purchase of shares for treasury (45,605 ) — — — (45,605 ) Proceeds from long-term debt 411,623 2,125 29,310 — 443,058 Payments of long-term debt (269,478 ) (5,403 ) (26,112 ) — (300,993 ) Change in short-term borrowings — 144 — — 144 Financing costs (7,793 ) — — — (7,793 ) Tax effect from exercise/vesting of equity awards, net — — — — — Dividends paid (49,797 ) — — — (49,797 ) Other, net (46,405 ) 4,733 14,691 27,032 51 Net cash provided by (used in) financing activities (7,455 ) 1,599 17,889 27,032 39,065 CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash used in discontinued operations — (16,394 ) (62,533 ) — (78,927 ) Effect of exchange rate changes on cash and equivalents — (159 ) 1,332 — 1,173 NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS 12,736 8,287 1,054 — 22,077 CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 3,240 8,066 36,375 — 47,681 CASH AND EQUIVALENTS AT END OF PERIOD $ 15,976 $ 16,353 $ 37,429 $ — $ 69,758 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 14,912 $ 24,889 $ 47,242 $ (72,131 ) $ 14,912 Net (income) loss from discontinued operations — (12,351 ) 15,222 — 2,871 Net cash provided by operating activities (10,771 ) 56,320 3,602 — 49,151 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (15 ) (27,902 ) (7,020 ) — (34,937 ) Acquired business, net of cash acquired — — (34,719 ) — (34,719 ) Purchase of securities (1,824 ) — — — (1,824 ) Proceeds from sale of property, plant and equipment — 144 (1 ) — 143 Net cash used in investing activities (1,839 ) (27,758 ) (41,740 ) — (71,337 ) CASH FLOWS FROM FINANCING ACTIVITIES: Purchase of shares for treasury (15,841 ) — — — (15,841 ) Proceeds from long-term debt 201,124 — 32,319 — 233,443 Payments of long-term debt (149,109 ) (1,282 ) (20,063 ) — (170,454 ) Share premium payment on settled debt (24,997 ) — — — (24,997 ) Change in short-term borrowings — — — — — Financing costs (1,548 ) — — — (1,548 ) Purchase of ESOP shares (10,908 ) — — — (10,908 ) Dividends paid (10,325 ) — — — (10,325 ) Other, net 20,937 (34,806 ) 13,799 — (70 ) Net cash used in financing activities 9,333 (36,088 ) 26,055 — (700 ) CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash provided by (used in) discontinued operations — (12,100 ) 9,950 — (2,150 ) Effect of exchange rate changes on cash and equivalents — — 164 — 164 NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS (3,277 ) (19,626 ) (1,969 ) — (24,872 ) CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 6,517 27,692 38,344 — 72,553 CASH AND EQUIVALENTS AT END OF PERIOD $ 3,240 $ 8,066 $ 36,375 $ — $ 47,681 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2016 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 30,010 $ 51,099 $ 62,708 $ (113,807 ) $ 30,010 Net income (loss) from discontinued operations — 10,905 (676 ) — 10,229 Net cash provided by (used in) operating activities (11,879 ) 87,252 4,745 — 80,118 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (259 ) (62,176 ) 3,159 — (59,276 ) Intercompany distributions — (2,726 ) (1,744 ) — (4,470 ) Proceeds from sale of property, plant and equipment — 763 7 — 770 Investment purchases 715 — — — 715 Net cash provided by (used in) investing activities 456 (64,139 ) 1,422 — (62,261 ) CASH FLOWS FROM FINANCING ACTIVITIES: Purchase of shares for treasury (65,307 ) — — — (65,307 ) Proceeds from long-term debt 271,340 2,311 28,711 — 302,362 Payments of long-term debt (177,513 ) (1,237 ) (29,764 ) — (208,514 ) Change in short-term borrowings — — — — — Financing costs (4,277 ) — (107 ) — (4,384 ) Tax effect from exercise/vesting of equity awards, net — — — — — Dividends paid (8,798 ) — — — (8,798 ) Other, net 55 (1,926 ) 1,926 — 55 Net cash provided by (used in) financing activities 15,500 (852 ) 766 — 15,414 CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash provided by (used in) discontinued operations — (5,241 ) (8,364 ) — (13,605 ) Effect of exchange rate changes on cash and equivalents — — 886 — 886 NET DECREASE IN CASH AND EQUIVALENTS 4,077 17,020 (545 ) — 20,552 CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 2,440 10,672 38,889 — 52,001 CASH AND EQUIVALENTS AT END OF PERIOD $ 6,517 $ 27,692 $ 38,344 $ — $ 72,553

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On November 14, 2018, the Board of Directors declared a cash dividend of $0.0725 per share, payable on December 20, 2018 to shareholders of record as of the close of business on November 29, 2018. Griffon currently intends to pay dividends each quarter; however, payment of dividends is determined by the Board of Directors, at its discretion, based on various factors, and no assurance can be provided as to the payment of future dividends. *****

SCHEDULE II VALUATION AND QUALI

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Sep. 30, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS	SCHEDULE II GRIFFON CORPORATION VALUATION AND QUALIFYING ACCOUNTS For the Years Ended September 30, 2018, 2017 and 2016 (in thousands) Description Balance at Beginning of Year Recorded to Cost and Expense Accounts Written Off, net Other (1) Balance at End of Year FOR THE YEAR ENDED SEPTEMBER 30, 2018 Allowance for Doubtful Accounts Bad debts $ 1,109 $ (40 ) 11 $ 744 $ 1,824 Sales returns and allowances 4,857 (5,880 ) 5,208 399 4,584 $ 5,966 $ (5,920 ) $ 5,219 $ 1,143 $ 6,408 Inventory valuation $ 16,419 $ 1,924 $ (306 ) $ 8,028 $ 26,065 Deferred tax valuation allowance $ 17,466 $ (8,946 ) $ — $ — $ 8,520 FOR THE YEAR ENDED SEPTEMBER 30, 2017 Allowance for Doubtful Accounts Bad debts $ 1,217 $ 279 $ (387 ) $ — $ 1,109 Sales returns and allowances 3,475 1,401 (19 ) — 4,857 $ 4,692 $ 1,680 $ (406 ) $ — $ 5,966 Inventory valuation $ 15,338 $ 851 $ 203 $ 27 $ 16,419 Deferred tax valuation allowance $ 12,832 $ 4,634 $ — $ — $ 17,466 FOR THE YEAR ENDED SEPTEMBER 30, 2016 Allowance for Doubtful Accounts Bad debts $ 1,628 $ 349 $ (759 ) $ (1 ) $ 1,217 Sales returns and allowances 2,277 1,205 (7 ) — 3,475 $ 3,905 $ 1,554 $ (766 ) $ (1 ) $ 4,692 Inventory valuation $ 13,003 $ 2,820 $ (728 ) $ 243 $ 15,338 Deferred tax valuation allowance $ 10,462 $ 2,370 $ — $ — $ 12,832 Note (1): For the year ended September 30, 2018, Other primarily consists of opening balances of reserves assumed from acquisitions.

DESCRIPTION OF BUSINESS AND S_2

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Consolidation	Consolidation The consolidated financial statements include the accounts of Griffon and all subsidiaries. Intercompany accounts and transactions have been eliminated in consolidation. The results of operations of acquired businesses are included from the dates of acquisitions.
Earnings per share	Earnings per share Due to rounding, the sum of earnings per share may not equal earnings per share of Net income.
Discontinued operations – Installation Services	Discontinued operations Installation Services In 2008, as a result of the downturn in the residential housing market, Griffon exited substantially all operating activities of its Installation Services segment which sold, installed and serviced garage doors and openers, fireplaces, floor coverings, cabinetry and a range of related building products, primarily for the new residential housing market. Operating results of substantially all of this segment have been reported as discontinued operations in the Consolidated Statements of Operations and Comprehensive Income (Loss) for all periods presented; Installation Services is excluded from segment reporting. During the year ended September 30, 2017, Griffon recorded $5,700 of reserves in discontinued operations related to historical environmental remediation efforts and to increase the reserve for homeowner association claims related to the Clopay Services Corporation discontinued operations in 2008.
Reclassifications	Reclassifications Certain amounts in prior years have been reclassified to conform to the current year presentation.
Use of estimates	Use of estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the reporting periods. These estimates may be adjusted due to changes in economic, industry or customer financial conditions, as well as changes in technology or demand. Significant estimates include allowances for doubtful accounts receivable and returns, net realizable value of inventories, restructuring reserves, valuation of goodwill and intangible assets, percentage of completion method of accounting, pension assumptions, useful lives associated with depreciation and amortization of intangible and fixed assets, warranty reserves, sales incentive accruals, stock based compensation assumptions, income taxes and tax valuation reserves, environmental reserves, legal reserves, insurance reserves, the valuation of assets and liabilities of discontinued operations, acquisition assumptions used and the accompanying disclosures. These estimates are based on management’s best knowledge of current events and actions Griffon may undertake in the future. Actual results may ultimately differ from these estimates.
Cash and equivalents	Cash and equivalents Griffon considers all highly liquid investments purchased with an initial maturity of three months or less to be cash equivalents. Cash equivalents primarily consist of overnight commercial paper, highly-rated liquid money market funds backed by U.S. Treasury securities and U.S. Agency securities, as well as insured bank deposits. Griffon had cash in non-U.S. bank accounts of approximately $24,900 and $26,500 at September 30, 2018 and 2017, respectively. Substantially all U.S. cash and equivalents are in excess of FDIC insured limits. Griffon regularly evaluates the financial stability of all institutions and funds that hold its cash and equivalents.
Fair value of financial instruments	Fair value of financial instruments The carrying values of cash and cash equivalents, accounts receivable, accounts and notes payable and revolving credit debt approximate fair value due to either the short-term nature of such instruments or the fact that the interest rate of the revolving credit debt is based upon current market rates. The fair value hierarchy, as outlined in the applicable accounting guidance, establishes a fair value hierarchy that requires the Company to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s categorization within the hierarchy is based on the lowest level of input that is significant to the fair value measurement. The accounting guidance establishes three levels of inputs that may be used to measure fair value, as follows: • Level 1 inputs are measured and recorded at fair value based upon quoted prices in active markets for identical assets. • Level 2 inputs include inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of assets or liabilities. • Level 3 inputs are unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The fair value of Griffon’s 2022 senior notes approximated $990,000 , on September 30, 2018 . Fair values were based upon quoted market prices (level 1 inputs). Insurance contracts with a value of $3,032 at September 30, 2018 are measured and recorded at fair value based upon quoted prices in active markets for similar assets (level 2 inputs) and are included in Other current assets on the consolidated balance sheet. Items Measured at Fair Value on a Recurring Basis At September 30, 2018 and 2017, trading securities, measured at fair value based on quoted prices in active markets for similar assets (level 2 inputs), with a fair value of $2,644 ( $2,086 cost basis) and $3,352 ( $1,000 cost basis) were included in Prepaid and other current assets on the Consolidated Balance Sheets. During the year ended September 30, 2018, the Company settled trading securities with proceeds totaling $4,126 and recognized a loss of $1,251 in Other income (expense). During the year ended September 30, 2016, the Company settled trading securities with proceeds totaling $715 and recognized a loss of $13 in Other income (expense). Realized and unrealized gains and losses on trading securities and realized gains and losses on available-for-sale securities are included in Other income in the Consolidated Statements of Operations and Comprehensive Income (Loss). In the normal course of business, Griffon’s operations are exposed to the effect of changes in foreign currency exchange rates. To manage these risks, Griffon may enter into various derivative contracts such as foreign currency exchange contracts, including forwards and options. During 2018 and 2017, Griffon entered into several such contracts in order to lock into a foreign currency rate for planned settlements of trade and inter-company liabilities payable in USD. At September 30, 2018 and 2017, Griffon had $12,000 and $14,500 of Australian dollar contracts at a weighted average rate of $1.38 and $1.28 , respectively, which qualified for hedge accounting. These hedges were all deemed effective as cash flow hedges with gains and losses related to changes in fair value deferred and recorded in Other comprehensive income (loss) and Prepaid and other current assets, or Accrued liabilities, until settlement. Upon settlement, gains and losses were recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) in Cost of goods and services. AOCI included deferred gains of $443 ( $288 , net of tax) and deferred gains of $175 ( $114 , net of tax) at September 30, 2018 and 2017, respectively. Upon settlement, gains (losses) of $657 and $(1,458) were recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) in Cost of goods and services ("COGS") during the years ended September 30, 2018 and September 30, 2017, respectively. All contracts expire in 31 to 92 days . At September 30, 2018 and 2017, Griffon had $700 and $4,690 , respectively, of Canadian dollar contracts at a weighted average rate of $1.29 and $1.25 . These contracts, which protect Canadian operations from currency fluctuations for U.S. dollar based purchases, do not qualify for hedge accounting and fair value losses of $7 and $378 were recorded in Other assets and to Other income for the outstanding contracts, based on similar contract values (level 2 inputs), for the years ended September 30, 2018 and 2017, respectively. Realized gains (losses) of $(161) and $200 , were recorded in Other income during the years ended September 30, 2018 and September 30, 2017, respectively. All contracts expire in 30 to 358 days . Pension plan assets with a fair value of $150,634 at September 30, 2018 , are measured and recorded at fair value based upon quoted prices in active markets for identical assets (level 1 inputs) and quoted market prices for similar assets (level 2 inputs).
Non-U.S. currency translation	Non-U.S. currency translation Assets and liabilities of non-U.S. subsidiaries, where the functional currency is not the U.S. dollar, have been translated at year-end exchange rates and profit and loss accounts have been translated using weighted average exchange rates. Adjustments resulting from currency translation have been recorded in the equity section of the balance sheet in AOCI as cumulative translation adjustments. Cumulative translation adjustments were gains of $9,403 and $10,667 for the year ended September 30, 2018 and 2017, respectively. As of September 30, 2018 and 2017, the foreign currency translation components of Accumulated other comprehensive loss were $22,824 and $32,227 , respectively. Assets and liabilities of an entity that are denominated in currencies other than that entity’s functional currency are re-measured into the functional currency using period end exchange rates, or historical rates where applicable to certain balances. Gains and losses arising on remeasurements are recorded within the Consolidated Statement of Operations and Comprehensive Income (Loss) as a component of Other income (expense).
Revenue recognition	Revenue recognition Revenue is recognized when the following circumstances are satisfied: a) persuasive evidence of an arrangement exists, b) delivery has occurred, title has transferred or services are rendered, c) price is fixed and determinable and d) collectability is reasonably assured. Goods are sold on terms that transfer title and risk of loss at a specified location. Revenue recognition from product sales occurs when all factors are met, including transfer of title and risk of loss, which occurs either upon shipment or upon receipt by customers at the location specified in the terms of sale. Other than standard product warranty provisions, sales arrangements provide for no other significant post-shipment obligations. From time to time and for certain customers, rebates and other sales incentives, promotional allowances or discounts are offered, typically related to customer purchase volumes, all of which are fixed or determinable and are classified as a reduction of revenue and recorded at the time of sale. Griffon provides for sales returns allowances based upon historical returns experience. Telephonics earns a substantial portion of its revenue as either a prime or subcontractor from contract awards with the U.S. Government, as well as non-U.S. governments and other commercial customers. These formal contracts are typically long-term in nature, usually greater than one year . Revenue and profits from these long-term fixed price contracts are recognized under the percentage-of-completion method of accounting. Revenue and profits on fixed-price contracts that contain engineering as well as production requirements are recorded based on the ratio of total actual incurred costs to date to the total estimated costs for each contract (cost-to-cost method). Using the cost-to-cost method, revenue is recorded at amounts equal to the ratio of actual cumulative costs incurred divided by total estimated costs at completion, multiplied by the total estimated contract revenue, less the cumulative revenue recognized in prior periods. The profit recorded on a contract using this method is equal to the current estimated total profit margin multiplied by the cumulative revenue recognized, less the amount of cumulative profit previously recorded for the contract in prior periods. As this method relies on the substantial use of estimates, these projections may be revised throughout the life of a contract. Components of this formula and ratio that may be estimated include gross profit margin and total costs at completion. The cost performance and estimates to complete on long-term contracts are reviewed, at a minimum, on a quarterly basis, as well as when information becomes available that would necessitate a review of the current estimate. Adjustments to estimates for a contract’s estimated costs at completion and estimated profit or loss often are required as experience is gained, and as more information is obtained, even though the scope of work required under the contract may or may not change, or if contract modifications occur. The impact of such adjustments or changes to estimates is made on a cumulative basis in the period when such information has become known. In 2018, 2017 and 2016, income from operations included net favorable/(unfavorable) catch-up adjustments approximating $1,400 , $600 and $(700) , respectively. Gross profit is affected by a variety of factors, including the mix of products, systems and services, production efficiencies, price competition and general economic conditions. Revenue and profits on cost-reimbursable type contracts are recognized as allowable costs, and are incurred on the contract at an amount equal to the allowable costs plus the estimated profit on those costs. The estimated profit on a cost-reimbursable contract may be fixed or variable based on the contractual fee arrangement. Incentive and award fees on these contracts are recorded as revenue when the criteria under which they are earned are reasonably assured of being met and can be estimated. For contracts in which anticipated total costs exceed the total expected revenue, an estimated loss is recognized in the period when identifiable. A provision for the entire amount of the estimated loss is recorded on a cumulative basis. The estimated remaining costs to complete loss contracts as of September 30, 2018 was $12,200 and is recorded as a reduction to gross margin on the Consolidated Statements of Operations and Comprehensive Income (Loss). This loss had an immaterial impact on Griffon's Consolidated Financial Statements. Amounts representing contract change orders or claims are included in revenue only when they can be reliably estimated and their realization is probable, and are determined on a percentage-of-completion basis measured by the cost-to-cost method. From time to time, Telephonics may combine contracts if they are negotiated together, have specific requirements to combine, or are otherwise closely related. Contracts are segmented based on customer requirements.
Accounts receivable, allowance for doubtful accounts and concentrations of credit risk	Accounts receivable, allowance for doubtful accounts and concentrations of credit risk Accounts receivable is composed principally of trade accounts receivable, that arise from the sale of goods or services on account, and is stated at historical cost. A substantial portion of Griffon’s trade receivables are from customers of HBP, of which the largest customer is Home Depot, whose financial condition is dependent on the construction and related retail sectors of the economy. As a percentage of consolidated accounts receivable, U.S. Government related programs were 8% and Home Depot was 20% . Griffon performs continuing evaluations of the financial condition of its customers, and although Griffon generally does not require collateral, letters of credit may be required from customers in certain circumstances. Trade receivables are recorded at the stated amount, less allowance for doubtful accounts and, when appropriate, for customer program reserves and cash discounts. The allowance represents estimated uncollectible receivables associated with potential customer defaults on contractual obligations (usually due to customers’ potential insolvency). The allowance for doubtful accounts includes amounts for certain customers where a risk of default has been specifically identified, as well as an amount for customer defaults based on a formula when it is determined the risk of some default is probable and estimable, but cannot yet be associated with specific customers. The provision related to the allowance for doubtful accounts is recorded in Selling, general and administrative ("SG&A") expenses. The Company writes-off accounts receivable when they are deemed to be uncollectible.
Contract costs and recognized income not yet billed	Contract costs and recognized income not yet billed Contract costs and recognized income not yet billed consists of amounts accounted for under the percentage of completion method of accounting, recoverable costs and accrued profit that cannot yet be invoiced under the terms of certain long-term contracts. Amounts will be invoiced when applicable contract terms, such as the achievement of specified milestones or product delivery, are met.
Inventories	Inventories Inventories, stated at the lower of cost (first-in, first-out or average) or market, include material, labor and manufacturing overhead costs. Griffon’s businesses typically do not require inventory that is susceptible to becoming obsolete or dated. In general, Telephonics sells products in connection with programs authorized and approved under contracts awarded by the U.S. Government or agencies thereof and in accordance with customer specifications. HBP produces doors, organizational and storage products and long-handled tools and landscaping products in response to orders from customers of retailers and dealers or based on expected orders, as applicable.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment includes the historical cost of land, buildings, equipment and significant improvements to existing plant and equipment or, in the case of acquisitions, a fair market value appraisal of such assets completed at the time of acquisition. Expenditures for maintenance, repairs and minor renewals are expensed as incurred. When property or equipment is sold or otherwise disposed of, the related cost and accumulated depreciation is removed from the respective accounts and the gain or loss is recognized. No event or indicator of impairment occurred during the three years ended September 30, 2018 , which would require additional impairment testing of property, plant and equipment. Depreciation expense, which includes amortization of assets under capital leases, was $46,733 , $41,220 and $39,734 for the years ended September 30, 2018 , 2017 and 2016, respectively, and was calculated on a straight-line basis over the estimated useful lives of the assets. Depreciation included in SG&A expenses was $16,306 , $12,995 and $11,721 for the years ended September 30, 2018 , 2017 and 2016. The remaining components of depreciation, attributable to manufacturing operations, are included in Cost of goods and services. Estimated useful lives for property, plant and equipment are as follows: buildings and building improvements, 25 to 40 years ; machinery and equipment, 2 to 15 years and leasehold improvements, over the term of the lease or life of the improvement, whichever is shorter.
Goodwill and indefinite-lived intangibles	Goodwill and indefinite-lived intangibles Goodwill is the excess of the acquisition cost of a business over the fair value of the identifiable net assets acquired. Goodwill is not amortized, but is subject to an annual impairment test unless during an interim period, impairment indicators such as a significant change in the business climate exist. Griffon performed its annual impairment testing of goodwill as of September 30, 2018 . The performance of the test involves a two-step process. The first step involves comparing the fair value of Griffon’s reporting units with the reporting unit’s carrying amount, including goodwill. Griffon generally determines the fair value of its reporting units using the income approach methodology of valuation that includes the present value of expected future cash flows. This method uses market assumptions specific to Griffon’s reporting units. If the carrying amount of a reporting unit exceeds the reporting unit’s fair value, Griffon performs the second step of the goodwill impairment test to determine the amount of impairment loss. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. Griffon defines its reporting units as its two reportable segments: HBP and Defense Electronics. At September 30, 2018 , HBP consisted of two components, AMES and CBP, because of their similar economic and qualitative characteristics. Griffon used 5 year projections and a 3.0% terminal value to which discount rates between 7% and 9.5% were applied to calculate each unit’s fair value. To substantiate fair values derived from the income approach methodology of valuation, the implied fair value was compared to the marketplace fair value of a comparable industry grouping for reasonableness. Further, the fair values were reconciled to Griffon’s market capitalization. Both market comparisons supported the implied fair values. Any changes in key assumptions or management judgment with respect to a reporting unit or its prospects, which may result from a decline in Griffon’s stock price, a change in market conditions, market trends, interest rates or other factors outside Griffon’s control, or significant underperformance relative to historical or project future operating results, could result in a significantly different estimate of the fair value of the reporting units, which could result in a future impairment charge (level 3 inputs). Based upon the results of the annual impairment review, it was determined that the fair value of each reporting unit substantially exceeded the carrying value of the assets, as performed under step one, and no impairment existed. Similar to goodwill, Griffon tests indefinite-lived intangible assets at least annually and when indicators of impairment exist. Griffon uses a relief from royalty method to calculate and compare the fair value of the intangible to its book value. This method uses market assumptions specific to Griffon’s reporting units, which are reasonable and supportable. If the fair value is less than the book value of the indefinite-lived intangibles, an impairment charge would be recognized.
Definite-lived long-lived assets	Definite-lived long-lived assets Amortizable intangible assets are carried at cost less accumulated amortization. For financial reporting purposes, definite-lived intangible assets are amortized on a straight-line basis over their useful lives, generally eight to twenty-five years . Long-lived assets and certain identifiable intangible assets to be held and used are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition.
Income taxes	Income taxes Income taxes are accounted for under the liability method. Deferred taxes reflect the tax consequences on future years of differences between the tax basis of assets and liabilities and their financial reporting amounts. The carrying value of Griffon’s deferred tax assets is dependent upon Griffon’s ability to generate sufficient future taxable income in certain tax jurisdictions. Should Griffon determine that it is more likely than not that some portion of the deferred tax assets will not be realized, a valuation allowance against the deferred tax assets would be established in the period such determination was made. Griffon provides for uncertain tax positions and any related interest and penalties based upon Management’s assessment of whether a tax benefit is more likely than not of being sustained upon examination by tax authorities. At September 30, 2018 Griffon believes that it has appropriately accounted for all unrecognized tax benefits. As of September 30, 2018 , 2017 and 2016, Griffon has recorded unrecognized tax benefits in the amount of $4,519 , $4,825 and $4,709 , respectively. Accrued interest and penalties related to income tax matters are recorded in the provision for income taxes.
Research and development costs, shipping and handling costs and advertising costs	Research and development costs, shipping and handling costs and advertising costs Research and development costs not recoverable under contractual arrangements are charged to SG&A expense as incurred and amounted to $15,400 , $17,700 and $18,000 in 2018 , 2017 and 2016, respectively. SG&A expenses include shipping and handling costs of $59,600 in 2018 , $32,500 in 2017 and $30,600 in 2016 and advertising costs, which are expensed as incurred, of $21,000 in 2018 , $22,000 in 2017 and $23,000 in 2016.
Risk, retention and insurance	Risk, retention and insurance Griffon’s property and casualty insurance programs contain various deductibles that, based on Griffon’s experience, are reasonable and customary for a company of its size and risk profile. Griffon generally maintains deductibles for claims and liabilities related primarily to workers’ compensation, general, product and automobile liability as well as property damage and business interruption losses resulting from certain events. Griffon does not consider any of the deductibles to represent a material risk to Griffon. Griffon accrues for claim exposures that are probable of occurrence and can be reasonably estimated. Insurance is maintained to transfer risk beyond the level of self-retention and provides protection on both an individual claim and annual aggregate basis.
Pension benefits	Pension benefits Griffon sponsors defined and supplemental benefit pension plans for certain retired employees. Annual amounts relating to these plans are recorded based on actuarial projections, which include various actuarial assumptions, including discount rates, assumed rates of return, compensation increases and turnover rates. Actuarial assumptions used to determine pension liabilities, assets and expense are reviewed annually and modified based on current economic conditions and trends. The expected return on plan assets is determined based on the nature of the plan's investments and expectations for long-term rates of return. The discount rate used to measure obligations is based on a corporate bond spot-rate yield curve that matches projected future benefit payments, with the appropriate spot rate applicable to the timing of the projected future benefit payments. Assumptions used in determining Griffon’s obligations under the defined benefit pension plans are believed to be reasonable, based on experience and advice from independent actuaries; however, differences in actual experience or changes in assumptions may materially impact Griffon’s financial position or results of operations. All of the defined benefit plans are frozen and have ceased accruing benefits.
Recently issued effective accounting pronouncements	Newly issued but not yet effective accounting pronouncements In August 2018, the FASB issued guidance on changes to the disclosure requirements for Fair Value Measurement, which eliminates, amends, and adds disclosure requirements for fair value measurements. The amended and new disclosure requirements primarily relate to Level 3 fair value measurements. The removal and amendment of certain disclosures may be early adopted with retrospective application while the new disclosure requirements are to be applied prospectively. The guidance is effective for the Company in fiscal 2021.We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In August 2018, the FASB issued guidance on changes to the disclosure requirements for defined benefit plans, which makes minor changes to the disclosure requirements related to defined benefit pension and other post-retirement plans. The guidance requires a retrospective transition approach and is effective for the Company in fiscal 2022. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In August 2018, the FASB issued guidance related to customer’s accounting for implementation costs incurred in a cloud computing arrangement that is a service contract. The guidance aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal-use software license). The guidance permits either a prospective or retrospective transition approach and is effective for the Company in fiscal 2021. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits entities to reclassify, to retained earnings, the one-time income tax effects stranded in accumulated other comprehensive income (AOCI) arising from the change in the U.S. federal corporate tax rate as a result of the Tax Cuts and Jobs Act of 2017. An entity that elects to make this reclassification must consider all items in AOCI that have tax effects stranded as a result of the tax rate change, and must disclose the reclassification of these tax effects as well as the entity’s policy for releasing income tax effects from AOCI. This guidance may be applied either retrospectively or as of the beginning of the period of adoption. The new guidance is effective for the Company beginning in fiscal 2020. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In May 2017, the FASB issued guidance to address the situation when a company modifies the terms of a stock compensation award previously granted to an employee. This guidance is effective, and should be applied prospectively, for fiscal years beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual period. The new guidance is effective for the Company beginning in fiscal 2019. We believe the implementation of this guidance will not have a material effect on the Company’s financial condition or results of operations. In March 2017, the FASB issued amendments to the Compensation - Retirement Benefits guidance which requires companies to retrospectively present the service cost component of net periodic benefit cost for pension and retiree medical plans along with other compensation costs in operating income and present the other components of net periodic benefit cost below operating income in the income statement. The guidance also allows only the service cost component of net periodic benefit cost to be eligible for capitalization within inventory or fixed assets on a prospective basis. This guidance is effective, and should be applied retroactively, for fiscal years beginning after December 15, 2017. Early adoption is permitted as of the beginning of an annual period. The new guidance is effective for the Company beginning in fiscal 2019. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In January 2017, the FASB issued guidance that simplifies how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. This guidance is effective for annual periods beginning after December 15, 2019, including interim periods within those periods and will be effective for the Company beginning in 2020. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In January 2017, the FASB issued guidance that clarifies the definition of a business, which will impact many areas of accounting including acquisitions, disposals, goodwill, and consolidation. The new standard is intended to help companies and other organizations evaluate whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This guidance is effective for annual periods beginning after December 15, 2017, including interim periods within those periods and will be effective for the Company beginning in fiscal 2019. We are currently evaluating the impact of the guidance and do not expect this guidance to have a material impact on the Company's financial condition, results of operations and related disclosures. In August 2016, the Financial Accounting Standards Board ("FASB") issued guidance on the Statement of Cash Flows Classification of certain cash receipts and cash payments (a consensus of the emerging issues take force). This guidance addresses the following eight specific cash flow issues: Debt prepayment or debt extinguishment costs; settlement of zero-coupon debt instruments or other debt instruments with coupon interest rates that are insignificant in relation to the effective interest rate of the borrowing; contingent consideration payments made after a business combination; proceeds from the settlement of insurance claims; proceeds from the settlement of corporate-owned life insurance policies (including bank-owned life insurance policies); distributions received from equity method investees; beneficial interests in securitization transactions; and separately identifiable cash flows and application of the predominance principle. This guidance will be effective for the Company beginning in fiscal 2019. We are currently evaluating the impact of the guidance on the Company's financial condition, results of operations and related disclosures. In February 2016, the FASB issued guidance on lease accounting requiring lessees to recognize a right-of-use asset and a lease liability for long-term leases. The liability will be equal to the present value of lease payments. This guidance must be applied using a modified retrospective transition approach to all annual and interim periods presented and is effective for the company beginning in fiscal 2020. We are currently evaluating the impact of the guidance on the Company's financial condition, results of operations and related disclosures. In May 2014, the FASB issued an Accounting Standards Update related to new revenue recognition guidance that supersedes the existing revenue recognition guidance and most industry-specific guidance applicable to revenue recognition. According to the new guidance, an entity will apply a principles-based five step model to recognize revenue upon the transfer of promised goods or services to customers and in an amount that reflects the consideration for which the entity expects to be entitled in exchange for those goods or services. The core principle of the guidance is that the recognition of revenue should depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which an entity expects to be entitled in exchange for those goods and services. The converged standard also includes more robust disclosure requirements which will require entities to provide sufficient information to enable users of financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Subsequently, the FASB has issued amendments to certain aspects of the guidance including the effective date. The effective date of this revised standard is for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. The converged standard can be adopted using a full retrospective method or a modified retrospective method, which applies the new guidance to contracts that are not completed at the adoption date without adjusting prior reporting periods. The Company has completed its assessment of the impact of this standard which will become effective for the Company in the first quarter of its 2019 fiscal year and will adopt this guidance using the modified retrospective method. Beginning in the second half of fiscal 2016, the Company used a team to analyze the impact of the standard, and the related guidance issued, across all revenue streams and to evaluate the impact of the new standard on revenue contracts. This team reviewed current accounting policies and practices, identifying potential differences that would result from applying the requirements under the new standard. As noted above, the Company will adopt this new standard in the first quarter of 2019 using the modified retrospective method of adoption. The standard will not impact revenue recognition practices at the Company’s Home and Building Products Segment but will have an impact at its Defense Electronics Segment. We will adopt the new standard by recognizing the cumulative effect of initially applying the new standard as an adjustment to the opening balance of retained earnings. We expect this adjustment to opening retained earnings to be approximately $5,000 with an immaterial impact to our net income on an ongoing basis. Recently adopted accounting pronouncements In March 2018, the FASB issued ASU 2018-05, Income Taxes Amendments to SEC Paragraphs Pursuant to the SEC SAB 118. This ASU provides guidance on income tax accounting implications under the TCJA. SAB 118 addressed the application of GAAP to situations when a registrant does not have the necessary information available, prepared and analyzed in reasonable detail to complete the accounting for certain income tax effects of the TCJA and allows companies to record provisional amounts during the re-measurement period not to exceed one year after the enactment date while the accounting impact remains under analysis. This guidance was effective immediately upon issuance. See Note 11 Income Taxes for further details. In March 2016, the FASB issued guidance on Stock Compensation: Improvements to Employee Share-Based Payment Accounting. The guidance changes how companies account for certain aspects of share-based payment awards to employees, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as the classification of related matters in the statement of cash flows. The amendments are effective for annual periods, and interim reporting periods within those annual periods, beginning after December 15, 2016 using either prospective, retrospective or modified retrospective transition method, depending on the area covered in this guidance. The Company early adopted this guidance in fiscal 2016 in order to simplify the accounting for employee share-based payments. Under this guidance all excess tax benefits (“windfalls”) and deficiencies (“shortfalls”) related to employee stock compensation was recognized within income tax expense for the year ended September 30, 2016. Under prior guidance, windfalls were recognized to Capital in excess of par value and shortfalls were only recognized to the extent they exceed the pool of windfall tax benefits. As a result of the adoption, a tax benefit of $2,193 was recognized within income tax expense reflecting the excess tax benefits for the year ended September 30, 2016. The adoption was on a prospective basis and therefore had no impact on prior years. Additionally, income tax benefits at settlement of an award were previously reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award's vesting period. Griffon has elected to apply that change in cash flow classification on a prospective basis, which has resulted in a $2,291 increase to net cash provided by operating activities and a corresponding increase to net cash used in financing activities in the accompanying condensed consolidated statement of cash flows for the year ended September 30, 2016, as compared to the amounts previously reported. The remaining provisions of this accounting standard did not have a material impact on the accompanying condensed consolidated financial statements. In August 2014, the FASB issued guidance on management's responsibility in evaluating whether there is substantial doubt about a company's ability to continue as a going concern and related footnote disclosures. Management is required to evaluate, at each reporting period, whether there are conditions or events that raise substantial doubt about a company's ability to continue as a going concern within one year from the date the financial statements are issued. This guidance was effective prospectively for annual and interim reporting periods beginning in 2017; implementation of this guidance did not have a material effect on the Company’s financial condition or results of operations. The Company has implemented all new accounting pronouncements that are in effect and that may impact its financial statements.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Sep. 30, 2018
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following unaudited proforma summary from continuing operations presents consolidated information as if the Company acquired ClosetMaid on October 1, 2016: Proforma Revenue $ 1,823,497 Income from continuing operations 15,070 Griffon did not include any material, nonrecurring proforma adjustments directly attributable to the business combination in the proforma revenue and earnings. These proforma amounts have been compiled by adding the historical results from continuing operations of Griffon, restated for classifying the results of operations of the PPC business as a discontinued operation, to the historical results of ClosetMaid after applying Griffon’s accounting policies and the following proforma adjustments: • Additional depreciation and amortization that would have been charged assuming the preliminary fair value adjustments to property, plant, and equipment, and intangible assets had been applied from October 1, 2016. • Elimination of intercompany interest income recorded on ClosetMaid’s financial statements earned on an intercompany receivable due from ClosetMaid’s former parent. • Additional interest and related expenses from the add-on offering of $275,000 for the aggregate principal amount of 5.25% senior notes due 2022 that Griffon used to acquire ClosetMaid. • Removal of $900 of restructuring costs from ClosetMaid's historical results for the year ended September 30, 2017. • The consequential tax effects of the above adjustments using a 39.7% tax rate for the year ended September 30, 2017. The calculation of the preliminary purchase price allocation, which is pending finalization of tax-related items and completion of the related final valuation, is as follows: Accounts receivable (1) $ 32,234 Inventories (2) 28,411 Property, plant and equipment 47,464 Goodwill 70,159 Intangible assets 74,580 Other current and non-current assets 3,852 Total assets acquired 256,700 Accounts payable and accrued liabilities 68,251 Long-term liabilities 2,720 Total liabilities assumed 70,971 Total $ 185,729 The calculation of the preliminary purchase price allocation, which is pending finalization of tax-related items and completion of the related final valuation, is as follows: Accounts receivable (1) $ 30,400 Inventories (2) 12,336 Property, plant and equipment 49,426 Goodwill 42,883 Intangible assets 67,600 Other current and non-current assets 2,648 Total assets acquired 205,293 Accounts payable and accrued liabilities 12,207 Long-term liabilities 660 Total liabilities assumed 12,867 Total $ 192,426 (1) Includes $30,818 of gross accounts receivable of which $418 was not expected to be collected. The fair value of accounts receivable approximated book value acquired. (2) Includes $13,433 of gross inventory of which $1,098 was reserved for obsolete items.
Schedule of Goodwill And Intangible Assets Acquired as Part of Business Combination	The preliminary amounts assigned to goodwill and major intangible asset classifications, all of which are tax deductible, for the CornellCookson acquisition are as follows: Average Goodwill $ 42,883 N/A Indefinite-lived intangibles 53,500 N/A Definite-lived intangibles 14,100 12 Total goodwill and intangible assets $ 110,483 The amounts assigned to goodwill and major intangible asset classifications, all of which are tax deductible, for the ClosetMaid acquisition are as follows: Average Goodwill $ 70,159 N/A Indefinite-lived intangibles 47,740 N/A Definite-lived intangibles 26,840 21 Total goodwill and intangible assets $ 144,739
Business Acquisition, Pro Forma Information	The following unaudited proforma summary from continuing operations presents consolidated information as if the Company acquired ClosetMaid on October 1, 2016: Proforma Revenue $ 1,823,497 Income from continuing operations 15,070

INVENTORIES (Tables)

INVENTORIES (Tables)	12 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	The following table details the components of inventory: At September 30, At September 30, Raw materials and supplies $ 97,645 $ 67,990 Work in process 83,578 78,846 Finished goods 217,136 152,601 Total $ 398,359 $ 299,437

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	12 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The following table details the components of property, plant and equipment, net: At September 30, At September 30, Land, building and building improvements $ 130,296 $ 71,764 Machinery and equipment 544,875 462,173 Leasehold improvements 50,111 43,040 725,282 576,977 Accumulated depreciation and amortization (382,790 ) (344,842 ) Total $ 342,492 $ 232,135

GOODWILL AND OTHER INTANGIBLES

GOODWILL AND OTHER INTANGIBLES (Tables)	12 Months Ended
	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table provides changes in carrying value of goodwill by segment through the year ended September 30, 2018 : At September 30, Goodwill from acquisitions Foreign currency translation adjustments September 30, Goodwill from acquisitions Foreign currency translation adjustments September 30, Home & Building Products $ 287,618 $ 12,417 $ 559 $ 300,594 $ 119,907 $ 349 $ 420,850 Defense Electronics 18,545 — — 18,545 — — 18,545 Total $ 306,163 $ 12,417 $ 559 $ 319,139 $ 119,907 $ 349 $ 439,395
Schedule Of Identifiable Intangible Assets	The following table provides the gross carrying value and accumulated amortization for each major class of intangible asset: At September 30, 2018 At September 30, 2017 Gross Carrying Amount Accumulated Amortization Average Life (Years) Gross Carrying Amount Accumulated Amortization Customer relationships & other $ 186,031 $ 49,822 23 $ 152,025 $ 43,421 Unpatented technology 19,004 6,238 13 6,193 4,719 Total amortizable intangible assets 205,035 56,060 158,218 48,140 Trademarks 221,883 — 95,049 — Total intangible assets $ 426,918 $ 56,060 $ 253,267 $ 48,140

DISCONTINUED OPERATIONS (Tables

DISCONTINUED OPERATIONS (Tables)	12 Months Ended
	Sep. 30, 2018
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures	The following amounts summarize the total assets and liabilities of PPC and Installation Services and other discontinued activities which have been segregated from Griffon’s continuing operations and are reported as assets and liabilities of discontinued operations in the consolidated balance sheets: At September 30, At September 30, Assets of discontinued operations: Prepaid and other current assets $ 324 $ 329 Other long-term assets 2,916 2,960 Total assets of discontinued operations $ 3,240 $ 3,289 Liabilities of discontinued operations: Accrued liabilities, current $ 7,210 $ 8,342 Other long-term liabilities 2,648 3,037 Total liabilities of discontinued operations $ 9,858 $ 11,379 The following amounts related to the PPC segment have been segregated from Griffon's continuing operations and are reported as discontinued operations: For the Year Ended September 30, 2018 2017 2016 Revenue $ 166,262 $ 460,914 $ 480,126 Cost of goods and services 132,100 389,416 407,385 Gross profit 34,162 71,498 72,741 Selling, general and administrative expenses 26,303 43,518 45,673 Restructuring charges — — 5,900 Total operating expenses 26,303 43,518 51,573 Income from discontinued operations 7,859 27,980 21,168 Other income (expense) Gain on sale of business 112,964 — — Interest expense, net (155 ) (63 ) (1,234 ) Other, net (687 ) 59 1,018 Total other income (expense) 112,122 (4 ) (216 ) Income from operations of discontinued operations 119,981 27,976 20,952 The following amounts related to PPC have been segregated from Griffon's continuing operations and are reported as assets and liabilities of discontinued operations held for sale in the consolidated balance sheet at September 30, 2017: At September 30, 2017 ASSETS Accounts receivable, net $ 51,768 Inventories, net 45,742 Prepaid and other current assets 11,000 PROPERTY, PLANT AND EQUIPMENT, net 185,940 GOODWILL 57,087 INTANGIBLE ASSETS, net 12,298 OTHER ASSETS 6,889 Total Assets Held for Sale $ 370,724 LIABILITIES Notes payable and current portion of long-term debt $ 11,163 Accounts payable 36,619 Accrued liabilities 14,553 LONG-TERM DEBT, net 10,549 OTHER LIABILITIES 11,566 Total Liabilities Held for Sale $ 84,450
Restructuring and Related Cost	The following amounts related to the PPC segment have been segregated from Griffon's continuing operations and are reported as discontinued operations: For the Year Ended September 30, 2018 2017 2016 Revenue $ 166,262 $ 460,914 $ 480,126 Cost of goods and services 132,100 389,416 407,385 Gross profit 34,162 71,498 72,741 Selling, general and administrative expenses 26,303 43,518 45,673 Restructuring charges — — 5,900 Total operating expenses 26,303 43,518 51,573 Income from discontinued operations 7,859 27,980 21,168 Other income (expense) Gain on sale of business 112,964 — — Interest expense, net (155 ) (63 ) (1,234 ) Other, net (687 ) 59 1,018 Total other income (expense) 112,122 (4 ) (216 ) Income from operations of discontinued operations 119,981 27,976 20,952

ACCRUED LIABILITIES (Tables)

ACCRUED LIABILITIES (Tables)	12 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	The following table details the components of accrued liabilities: At September 30, At September 30, Compensation $ 50,251 $ 37,692 Interest 4,776 3,671 Warranties and rebates 11,227 6,236 Insurance 25,329 12,216 Rent, utilities and freight 4,830 2,149 Income and other taxes 8,016 6,291 Marketing and advertising 3,685 1,859 Acquisition related accruals 17,448 — Other 13,630 13,144 Total $ 139,192 $ 83,258

WARRANTY LIABILITY (Tables)

WARRANTY LIABILITY (Tables)	12 Months Ended
	Sep. 30, 2018
Product Warranties Disclosures [Abstract]
Schedule of Product Warranty Liability	Changes in Griffon’s warranty liability, included in Accrued liabilities, were as follows: Years Ended September 30, 2018 2017 Balance, beginning of period $ 6,236 $ 6,322 Warranties issued and changes in estimated pre-existing warranties 8,770 6,393 Actual warranty costs incurred (7,948 ) (6,479 ) Other warranty liabilities assumed from acquisitions $ 1,116 $ — Balance, end of period $ 8,174 $ 6,236

NOTES PAYABLE, CAPITALIZED LE_2

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Tables)	12 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Future Minimum Lease Payments for Capital Leases	The present value of the net minimum payments on capitalized leases as of September 30, 2018 was follows: At September 30, Total minimum lease payments $ 10,586 Less amount representing interest payments (812 ) Present value of net minimum lease payments 9,774 Current portion (3,579 ) Capitalized lease obligation, less current portion $ 6,195
Schedule of Debt	) On October 2, 2017, in an unregistered offering through a private placement under Rule 144A, Griffon completed the add-on offering of $275,000 principal amount of its 5.25% senior notes due 2022, at 101.0% of par, to Griffon's previously issued $125,000 principal amount of its 5.25% senior notes due 2022, at 98.76% of par, completed on May 18, 2016 and $600,000 5.25% senior notes due in 2022 , at par, which was completed on February 27, 2014 (collectively the “Senior Notes”). As of September 30, 2018, outstanding Senior Notes due totaled $1,000,000 ; interest is payable semi-annually on March 1 and September 1. The net proceeds of the $275,000 add-on offering were used to acquire ClosetMaid with the remaining proceeds used to pay down outstanding loan borrowings under Griffon's Revolving Credit Facility (the "Credit Agreement"). The net proceeds of the previously issued $125,000 add-on offering were used to pay down outstanding revolving loan borrowings under the Credit Agreement. Proceeds from the $600,000 5.25% senior notes due in 2022 were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a call and tender offer premium of $31,530 and to make interest payments of $16,716 , with the balance used to pay a portion of the related transaction fees and expenses. In connection with the issuance of the Senior Notes, all obligations under the $550,000 of 7.125% senior notes due in 2018 were discharged. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On February 5, 2018, July 20, 2016 and June 18, 2014, Griffon exchanged all of the $275,000 , $125,000 and $600,000 Senior Notes, respectively, for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer. The fair value of the Senior Notes approximated $990,000 on September 30, 2018 based upon quoted market prices (level 1 inputs). In connection with the issuance and exchange of the $275,000 senior notes, Griffon capitalized $8,472 of underwriting fees and other expenses; in addition to $13,329 capitalized under the previously issued $725,000 Senior Notes. All capitalized fees for the Senior Notes will amortize over the term of the notes and, at September 30, 2018, $14,830 remained to be amortized. (b) On March 22, 2016, Griffon amended its Credit Agreement to increase the credit facility from $250,000 to $350,000 , extend its maturity from March 13, 2020 to March 22, 2021, and modify certain other provisions of the facility. On October 2, 2017 and on May 31, 2018, Griffon amended the Credit Agreement in connection with the ClosetMaid and the CornellCookson acquisitions, respectively, to modify the net leverage covenant. The facility includes a letter of credit sub-facility with a limit of $50,000 and a multi-currency sub-facility of $100,000 . The Credit Agreement provides for same day borrowings of base rate loans. Borrowings under the Credit Agreement may be repaid and re-borrowed at any time, subject to final maturity of the facility or the occurrence of an event of default under the Credit Agreement. Interest is payable on borrowings at either a LIBOR or base rate benchmark rate, in each case without a floor, plus an applicable margin, which adjusts based on financial performance. Current margins are 1.75% for base rate loans and 2.75% for LIBOR loans. The Credit Agreement has certain financial maintenance tests including a maximum total leverage ratio, a maximum senior secured leverage ratio and a minimum interest coverage ratio, as well as customary affirmative and negative covenants and events of default. The negative covenants place limits on Griffon's ability to, among other things, incur indebtedness, incur liens, and make restricted payments and investments. Borrowings under the Credit Agreement are guaranteed by Griffon’s material domestic subsidiaries and are secured, on a first priority basis, by substantially all domestic assets of the Company and the guarantors, and a pledge of not greater than 65% of the equity interest in Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon’s material domestic subsidiaries securing a limited amount of the debt under the credit agreement relating to Griffon's Employee Stock Ownership Plan ("ESOP") ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (e) below). At September 30, 2018 , under the Credit Agreement, there were $25,000 outstanding borrowings; outstanding standby letters of credit were $14,623 ; and $310,377 was available, subject to certain loan covenants, for borrowing at that date. (c) On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000 , if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858 , or 1,954,993 shares of common stock issued from treasury. (d) In September 2015 and March 2016, Griffon entered into mortgage loans in the amount of $32,280 and $8,000 , respectively, and were due to mature in September 2025 and April 2018, respectively. The mortgage loans were secured and collateralized by four properties occupied by Griffon's subsidiaries and were guaranteed by Griffon. The loans had an interest at a rate of LIBOR plus 1.50% . The loans were paid off during the year ended September 30, 2018. (e) In August 2016, Griffon’s ESOP entered into an agreement that refinanced the existing ESOP loan into a new Term Loan in the amount of $35,092 (the "Agreement"). The Agreement also provided for a Line Note with $10,908 available to purchase shares of Griffon common stock in the open market. During 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized. On June 30, 2017, the Term Loan and Line Note were combined into a single Term Loan. The Term Loan bears interest at LIBOR plus 3.0% . The Term Loan requires quarterly principal payments of $569 with a balloon payment due at maturity on March 22, 2020. As a result of the special cash dividend of $1.00 per share, paid on April 16, 2018, the outstanding balance of the Term Loan was reduced by $5,705 . As of September 30, 2018 , $34,508 , net of issuance costs, was outstanding under the Term Loan. The Term Loan is secured by shares purchased with the proceeds of the loan and with a lien on a specific amount of Griffon assets (which lien ranks pari passu with the lien granted on such assets under the Credit Agreement) and is guaranteed by Griffon. (f) Two Griffon subsidiaries have capital leases outstanding for real estate located in Troy, Ohio and Ocala, Florida. The leases mature in 2021 and 2022, respectively, and bear interest at fixed rates of approximately 5.0% and 8.0% , respectively. The Troy, Ohio lease is secured by a mortgage on the real estate and is guaranteed by Griffon. The Ocala, Florida lease contains two five-year renewal options. As of September 30, 2018, $7,423 was outstanding, net of issuance costs. (g) In November 2012, Garant G.P. (“Garant”) entered into a CAD 15,000 ( $11,498 as of September 30, 2018) revolving credit facility. The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum ( 3.70% LIBOR USD and 3.24% Bankers Acceptance Rate CDN as of September 30, 2018 ). The revolving facility matures in October 2019. Garant is required to maintain a certain minimum equity. As of September 30, 2018 , there were no borrowings under the revolving credit facility with CAD 15,000 ( $11,498 as of September 30, 2018 ) available for borrowing. In July 2016, Griffon Australia Holdings Pty Ltd and its Australian subsidiaries ("Griffon Australia") entered into an AUD 30,000 term loan and an AUD 10,000 revolver. The term loan refinanced two existing term loans and the revolver replaced two existing lines. In December 2016, the amount available under the revolver was increased from AUD 10,000 to AUD 20,000 and, in March 2017 the term loan commitment was increased by AUD 5,000 . In September 2017, the term commitment was increased by AUD 15,000 . The term loan requires quarterly principal payments of AUD 1,250 plus interest with a balloon payment of AUD 37,125 due upon maturity in October 2019, and accrues interest at Bank Bill Swap Bid Rate “BBSY” plus 2.00% per annum ( 3.99% at September 30, 2018 ). As of September 30, 2018 , the term had an outstanding balance of AUD 40,875 ( $29,546 as of September 30, 2018). The revolving facility matures in March 2019, but is renewable upon mutual agreement with the lender, and accrues interest at BBSY plus 2.0% per annum ( 3.90% at September 30, 2018). At September 30, 2018, the revolver had an outstanding balance of AUD 11,000 ( $7,951 at September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Griffon Australia and its subsidiaries. Griffon guarantees the term loan. Griffon Australia is required to maintain a certain minimum equity level and is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. A UK subsidiary of Griffon maintained an invoice discounting arrangement secured by trade receivables. Interest was variable at 2.0% over the Sterling base rate. This facility was canceled in July 2018. In July 2018, the AMES Companies UK Ltd and its subsidiaries ("Ames UK") entered into a GBP 14,000 term loan, GBP 4,000 mortgage loan and GBP 5,000 revolver. The term loan and mortgage loan require quarterly principal payments of GBP 350 and GBP 83 plus interest, respectively, and have balloon payments due upon maturity, July 2023, of GBP 7,000 and GBP 2,333 , respectively. The Term Loan and Mortgage Loans accrue interest at the GBP LIBOR Rate plus 2.25% and 1.8% , respectively ( 3.05% and 2.60% at September 30, 2018, respectively). The revolving facility matures in July 2019, but is renewable upon mutual agreement with the lender, and accrues interest at the Bank of England Base Rate plus 1.5% ( 2.25% as of September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Ames UK and its subsidiaries. Ames UK is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. The invoice discounting arrangement was canceled and replaced by the above loan facilities. As of September 30, 2018, outstanding borrowings on these facilities totaled $23,987 . (h) Other long-term debt primarily consists of a loan with the Pennsylvania Industrial Development Authority, with the balance consisting of capital leases. Debt at September 30, 2018 and 2017 consisted of the following: At September 30, 2018 Outstanding Balance Original Issuer Discount Capitalized Fees & Expenses Balance Sheet Coupon Interest Rate Senior note due 2022 (a) $ 1,000,000 1,220 $ (12,968 ) $ 988,252 5.25 % Revolver due 2021 (b) 25,000 — (1,413 ) 23,587 n/a ESOP Loans (e) 34,694 — (186 ) 34,508 n/a Capital lease - real estate (f) 7,503 — (80 ) 7,423 5.00 % Non U.S. lines of credit (g) 7,951 (16 ) 7,935 n/a Non U.S. term loans (g) 53,533 — (148 ) 53,385 n/a Other long term debt (h) 6,011 — (19 ) 5,992 n/a Totals 1,134,692 1,220 (14,830 ) 1,121,082 less: Current portion (13,011 ) — — (13,011 ) Long-term debt $ 1,121,681 $ 1,220 $ (14,830 ) $ 1,108,071 At September 30, 2017 Outstanding Balance Original Issuer Discount Capitalized Balance Sheet Coupon Interest Rate Senior notes due 2022 (a) $ 725,000 $ (1,177 ) $ (9,220 ) $ 714,603 5.25 % Revolver due 2021 (b) 144,216 — (1,951 ) 142,265 n/a Real estate mortgages (d) 23,642 — (320 ) 23,322 n/a ESOP Loans (e) 42,675 — (310 ) 42,365 n/a Capital lease - real estate (f) 5,312 — (105 ) 5,207 5.00 % Non U.S. lines of credit (g) 9,402 (31 ) 9,371 n/a Non U.S. term loans (g) 35,943 — (108 ) 35,835 n/a Other long term debt (h) 6,211 — (21 ) 6,190 Totals 992,401 (1,177 ) (12,066 ) 979,158 less: Current portion (11,078 ) — — (11,078 ) Long-term debt $ 981,323 $ (1,177 ) $ (12,066 ) $ 968,080

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables)	12 Months Ended
	Sep. 30, 2018
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs	Net periodic costs (benefits) were as follows: Defined Benefits for the Years Ended September 30, Supplemental Benefits for the Years Ended September 30, 2018 2017 2016 2018 2017 2016 Net periodic (benefits) costs: Interest cost $ 5,084 $ 4,892 $ 5,465 $ 544 $ 715 $ 1,243 Expected return on plan assets (10,736 ) (10,943 ) (10,934 ) — — — Amortization of: Prior service costs — 1 1 14 15 19 Actuarial loss 755 1,980 1,131 628 1,347 1,224 Total net periodic (benefits) costs $ (4,897 ) $ (4,070 ) $ (4,337 ) $ 1,186 $ 2,077 $ 2,486
Schedule of Assumptions Used	The weighted-average assumptions used in determining the net periodic (benefits) costs were as follows: Defined Benefits for the Years Ended September 30, Supplemental Benefits for the Years Ended September 30, 2018 2017 2016 2018 2017 2016 Discount rate 4.10 % 3.64 % 3.42 % 3.99 % 3.18 % 2.86 % Expected return on assets 7.00 % 7.25 % 7.50 % — % — % — %
Schedule Of Plan Assets And Benefit Obligation Of Defined Benefit Plan	Plan assets and benefit obligation of the defined and supplemental benefit plans were as follows: Defined Benefits at September 30, Supplemental Benefits at September 30, 2018 2017 2018 2017 Change in benefit obligation: Benefit obligation at beginning of fiscal year $ 174,337 $ 189,156 $ 32,627 $ 35,774 Interest cost 5,084 4,892 544 715 Benefits paid (10,531 ) (10,393 ) (3,001 ) (4,057 ) Actuarial (gain) loss (7,562 ) (9,318 ) (14,452 ) 195 Benefit obligation at end of fiscal year 161,328 174,337 15,718 32,627 Change in plan assets: Fair value of plan assets at beginning of fiscal year 150,822 144,316 — — Actual return on plan assets 7,940 13,152 — — Company contributions 2,449 3,747 3,001 4,057 Benefits paid (10,531 ) (10,393 ) (3,001 ) (4,057 ) Fair value of plan assets at end of fiscal year 150,680 150,822 — — Projected benefit obligation in excess of plan assets $ (10,648 ) $ (23,515 ) $ (15,718 ) $ (32,627 ) Amounts recognized in the statement of financial position consist of: Accrued liabilities $ — $ — $ (1,906 ) $ (3,984 ) Other liabilities (long-term) (10,648 ) (23,515 ) (13,812 ) (28,643 ) Total Liabilities (10,648 ) (23,515 ) (15,718 ) (32,627 ) Net actuarial losses 19,088 24,608 4,965 20,045 Prior service cost — — 28 42 Deferred taxes (6,103 ) (9,069 ) (1,597 ) (7,486 ) Total Accumulated other comprehensive loss, net of tax 12,985 15,539 3,396 12,601 Net amount recognized at September 30, $ 2,337 $ (7,976 ) $ (12,322 ) $ (20,026 ) Accumulated benefit obligations $ 161,328 $ 174,337 $ 15,718 $ 32,627 Information for plans with accumulated benefit obligations in excess of plan assets: ABO $ 161,328 $ 174,337 $ 15,718 $ 32,627 PBO 161,328 174,337 15,718 32,627 Fair value of plan assets 150,680 150,822 — —
Schedule Of Weighted Average Assumptions Used in Defined And Supplemental Benefit Obligations	The weighted-average assumptions used in determining the benefit obligations were as follows: Defined Benefits at September 30, Supplemental Benefits at September 30, 2018 2017 2018 2017 Weighted average discount rate 4.10 % 3.64 % 3.99 % 3.18 %
Schedule Of Actual And Weighted Average Assets Allocation for Qualified Benefit plans	The actual and weighted-average asset allocation for qualified benefit plans were as follows: At September 30, 2018 2017 Target Cash and equivalents 18.0 % 18.0 % — % Equity securities 68.5 % 58.0 % 63.0 % Fixed income 9.5 % 19.3 % 37.0 % Other 4.0 % 4.7 % — % Total 100.0 % 100.0 % 100.0 %
Schedule of Expected Benefit Payments	Estimated future benefit payments to retirees, which reflect expected future service, are as follows: For the years ending September 30, Defined Benefits Supplemental Benefits 2019 $ 10,767 $ 1,906 2020 10,892 1,822 2021 10,979 1,734 2022 10,960 1,642 2023 10,950 1,545 2024 through 2028 53,652 6,068
Schedule Of Fair Value Of Pension And Post Retirement Plan Assets By Asset Category	The following table presents the fair values of Griffon’s pension and post-retirement plan assets by asset category: At September 30, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash and equivalents $ 27,209 $ — $ — $ 27,209 Debt instruments 14,269 — — 14,269 Equity securities 41,042 — — 41,042 Commingled funds — 62,088 — 62,088 Limited partnerships and hedge fund investments — 6,026 — 6,026 Total $ 82,520 $ 68,114 $ — $ 150,634 At September 30, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total Cash and equivalents $ 27,156 $ — $ — $ 27,156 Debt instruments 14,520 — — 14,520 Equity securities 40,423 — — 40,423 Commingled funds — 62,907 — 62,907 Limited partnerships and hedge fund investments — 5,816 — 5,816 Total $ 82,099 $ 68,723 $ — $ 150,822
Employee Stock Ownership Plan (ESOP) Disclosures	The ESOP shares were as follows: At September 30, 2018 2017 Allocated shares 3,157,530 2,676,486 Unallocated shares 2,477,385 3,125,850 Total 5,634,915 5,802,336

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule Of Income Loss From Continuing Operations Before Taxes	Income taxes have been based on the following components of Income before taxes from continuing operations: For the Years Ended September 30, 2018 2017 2016 Domestic $ 4,942 $ (1,339 ) $ 23,163 Non-U.S. 28,868 18,037 9,050 $ 33,810 $ 16,698 $ 32,213
Schedule of Components of Income Tax Expense (Benefit)	Provision (benefit) for income taxes on income was comprised of the following from continuing operations: For the Years Ended September 30, 2018 2017 2016 Current $ 18,188 $ (3,426 ) $ 6,388 Deferred (17,633 ) 2,341 6,044 Total $ 555 $ (1,085 ) $ 12,432 U.S. Federal $ (12,714 ) $ (6,689 ) $ 4,358 State and local 5,175 3,307 3,287 Non-U.S. 8,094 2,297 4,787 Total provision $ 555 $ (1,085 ) $ 12,432
Schedule of Effective Income Tax Rate Reconciliation	Differences between the effective income tax rate applied to Income and U.S. Federal income statutory rate from continuing operations were as follows: For the Years Ended September 30, 2018 2017 2016 U.S. Federal income tax provision (benefit) rate 24.5 % 35.0 % 35.0 % State and local taxes, net of Federal benefit 10.2 % 12.4 % 6.6 % Non-U.S. taxes - foreign permanent items and taxes 3.6 % (12.4 )% (1.6 )% Non-U.S. tax true-up — % (11.4 )% — % Change in domestic manufacturing deduction — % (5.8 )% — % Change in tax contingency reserves (0.6 )% 0.7 % (6.3 )% Impact of federal rate change on deferred tax balances (60.0 )% — % — % Repatriation of foreign earnings 61.6 % — % — % Change in valuation allowance 13.4 % (0.6 )% (0.6 )% Non-deductible/non-taxable items, net (2.4 )% 8.3 % 2.6 % Research and U.S. foreign tax credits (39.4 )% (3.6 )% 8.8 % Share based compensation (3.8 )% (26.6 )% (5.7 )% Other (5.5 )% (2.5 )% (0.2 )% Effective tax provision (benefit) rate 1.6 % (6.5 )% 38.6 %
Schedule of Deferred Tax Assets and Liabilities	The tax effect of temporary differences that give rise to future deferred tax assets and liabilities are as follows: At September 30, 2018 2017 Deferred tax assets: Bad debt reserves $ 1,404 $ 2,509 Inventory reserves 7,709 7,615 Deferred compensation (equity compensation and defined benefit plans) 11,437 27,430 Compensation benefits 5,434 6,111 Insurance reserve 1,782 2,985 Restructuring reserve — 29 Warranty reserve 2,598 2,893 Net operating loss 10,593 37,383 Tax credits 6,379 1,866 Other reserves and accruals 5,433 7,658 52,769 96,479 Valuation allowance (8,520 ) (17,466 ) Total deferred tax assets 44,249 79,013 Deferred tax liabilities: Deferred income — (1,862 ) Goodwill and intangibles (44,402 ) (70,560 ) Property, plant and equipment (39,260 ) (51,488 ) Deferred gain on assets held for sale — (16,300 ) Other (1,086 ) (1,016 ) Total deferred tax liabilities (84,748 ) (141,226 ) Net deferred tax liabilities $ (40,499 ) $ (62,213 )
Schedule Of Components of Net Deferred Tax Asset Liability By Balance Sheet Account	The components of the net deferred tax liability, by balance sheet account, were as follows: At September 30, 2018 2017 Other assets $ 61 $ 6 Assets of discontinued operations held for sale — 6,745 Other liabilities (42,689 ) (58,505 ) Liabilities of discontinued operations held for sale 872 (12,584 ) Liabilities of discontinued operations not held for sale 1,257 2,125 Net deferred liability $ (40,499 ) $ (62,213 )
Schedule of Unrecognized Tax Benefits Roll Forward	The following is a roll forward of unrecognized tax benefits: Balance at September 30, 2016 $ 4,709 Additions based on tax positions related to the current year 177 Additions based on tax positions related to prior years 69 Reductions based on tax positions related to prior years (8 ) Lapse of Statutes (122 ) Balance at September 30, 2017 4,825 Additions based on tax positions related to the current year 152 Reductions based on tax positions related to prior years (253 ) Additions based on tax positions related to prior years 26 Lapse of Statutes (194 ) Settlements (37 ) Balance at September 30, 2018 $ 4,519

STOCKHOLDERS' EQUITY AND EQUI_2

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Tables)	12 Months Ended
	Sep. 30, 2018
Stockholders' Equity Note [Abstract]
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan	The following table summarizes the Company’s compensation expense relating to all stock-based incentive plans: For the Years Ended September 30, 2018 2017 2016 Pre-tax compensation expense $ 10,078 $ 8,090 $ 10,136 Tax benefit (2,469 ) (2,836 ) (3,553 ) Total stock-based compensation expense, net of tax $ 7,609 $ 5,254 $ 6,583
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	A summary of restricted stock activity, inclusive of restricted stock units, for the year ended September 30, 2018 , is as follows: Shares Weighted Average Grant- Date Fair Value Unvested at September 30, 2017 2,255,796 $ 13.65 Granted 1,343,929 17.30 Vested (536,958 ) 20.89 Forfeited (212,939 ) 20.91 Unvested at September 30, 2018 2,849,828 14.89

EARNINGS PER SHARE EARNINGS PER

EARNINGS PER SHARE EARNINGS PER SHARE (Tables)	12 Months Ended
	Sep. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted EPS for the years ended September 30, 2018 , 2017 and 2016 were determined using the following information (in thousands): 2018 2017 2016 Weighted average shares outstanding - basic 41,005 41,005 41,074 Incremental shares from stock based compensation 1,417 1,642 2,326 Convertible debt due 2017 — 364 709 Weighted average shares outstanding - diluted 42,422 43,011 44,109 Anti-dilutive options excluded from diluted EPS computation — — 6

QUARTERLY FINANCIAL INFORMATI_2

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Tables)	12 Months Ended
	Sep. 30, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Quarterly results of continuing operations for the years ended September 30, 2018 and 2017 were as follows: Quarter ended Revenue Gross Profit Income from continuing operations Per Share - Basic Per Share - Diluted 2018 December 31, 2017 $ 437,303 $ 120,844 $ 22,831 $ 0.54 $ 0.53 March 31, 2018 478,560 121,473 1,951 0.05 0.05 June 30, 2018 516,550 138,792 7,442 0.18 0.18 September 30, 2018 545,505 148,451 1,031 0.03 0.02 $ 1,977,918 $ 529,560 $ 33,255 $ 0.81 $ 0.78 2017 December 31, 2016 $ 352,277 $ 96,744 $ 7,044 $ 0.18 $ 0.17 March 31, 2017 383,807 98,869 1,950 0.05 0.05 June 30, 2017 358,114 97,984 4,452 0.11 0.10 September 30, 2017 430,799 114,519 4,337 0.10 0.10 $ 1,524,997 $ 408,116 $ 17,783 $ 0.43 $ 0.41

REPORTABLE SEGMENTS (Tables)

REPORTABLE SEGMENTS (Tables)	12 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Information on Griffon’s reportable segments from continuing operations is as follows: For the Years Ended September 30, REVENUE 2018 2017 2016 Home & Building Products: AMES $ 953,612 $ 545,269 $ 513,973 CBP 697,969 568,001 527,370 Home & Building Products 1,651,581 1,113,270 1,041,343 Defense Electronics 326,337 $ 411,727 $ 435,692 Total consolidated net sales $ 1,977,918 $ 1,524,997 $ 1,477,035 For the Years Ended September 30, INCOME BEFORE TAXES FROM CONTINUING OPERATIONS 2018 2017 2016 Segment operating profit: Home & Building Products $ 130,487 $ 89,495 $ 79,682 Defense Electronics 25,262 29,943 42,801 Segment operating profit from continuing operations 155,749 119,438 122,483 Net interest expense (63,871 ) (51,449 ) (49,877 ) Unallocated amounts (45,812 ) (42,398 ) (40,393 ) Acquisition costs (5,217 ) (8,893 ) — Special dividend charges (3,220 ) — — Cost of life insurance benefit (2,614 ) — — Secondary equity offering costs (1,205 ) — — Income before taxes from continuing operations $ 33,810 $ 16,698 $ 32,213 The following table provides a reconciliation of Segment adjusted EBITDA to Income before taxes and discontinued operations: For the Years Ended September 30, 2018 2017 2016 Segment adjusted EBITDA: Home & Building Products $ 177,400 $ 126,766 $ 114,949 Defense Electronics 36,063 45,931 53,385 Total Segment adjusted EBITDA from continuing operations 213,463 172,697 168,334 Net interest expense (63,871 ) (51,449 ) (49,877 ) Segment depreciation and amortization (55,334 ) (47,398 ) (45,851 ) Unallocated amounts (45,812 ) (42,398 ) (40,393 ) Acquisition costs (7,597 ) (9,617 ) — Special dividend charges (3,220 ) — — Cost of life insurance benefit (2,614 ) — — Secondary equity offering costs (1,205 ) — — Contract settlement charges — (5,137 ) — Income before taxes from continuing operations $ 33,810 $ 16,698 $ 32,213
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	For the Years Ended September 30, DEPRECIATION and AMORTIZATION 2018 2017 2016 Segment: Home & Building Products $ 44,533 $ 36,547 $ 35,267 Defense Electronics 10,801 10,851 10,584 Total segment depreciation and amortization 55,334 47,398 45,851 Corporate 469 480 491 Total consolidated depreciation and amortization $ 55,803 $ 47,878 $ 46,342 CAPITAL EXPENDITURES Segment: Home & Building Products $ 36,587 $ 24,476 $ 49,351 Defense Electronics 10,941 8,204 9,007 Total segment 47,528 32,680 58,358 Corporate 2,610 2,257 918 Total consolidated capital expenditures $ 50,138 $ 34,937 $ 59,276 ASSETS At September 30, 2018 At September 30, 2017 At September 30, 2016 Segment assets: Home & Building Products $ 1,631,631 $ 1,084,103 $ 1,020,297 Defense Electronics 346,907 343,445 334,631 Total segment assets 1,978,538 1,427,548 1,354,928 Corporate 103,112 71,980 62,257 Total continuing assets 2,081,650 1,499,528 1,417,185 Assets of discontinued operations 3,240 374,013 364,911 Consolidated total $ 2,084,890 $ 1,873,541 $ 1,782,096
Schedule Of Segment Information By Geographic Region	Segment information by geographic region was as follows: For the Years Ended September 30, REVENUE BY GEOGRAPHIC AREA - DESTINATION 2018 2017 2016 United States $ 1,521,187 $ 1,164,958 $ 1,149,448 Europe 102,814 67,048 68,604 Canada 123,341 106,080 102,333 Australia 166,980 124,757 106,780 All other countries 63,596 62,154 49,870 Consolidated revenue $ 1,977,918 $ 1,524,997 $ 1,477,035 For the Years Ended September 30, LONG-LIVED ASSETS BY GEOGRAPHIC AREA 2018 2017 2016 United States $ 612,294 $ 358,795 $ 370,332 Canada 33,884 36,383 35,984 Australia 33,288 35,917 26,196 United Kingdom 24,892 4,144 — Mexico 7,017 — — All other countries 1,976 2,023 2,342 Consolidated long-lived assets, net $ 713,351 $ 437,262 $ 434,854

OTHER COMPREHENSIVE INCOME (L_2

OTHER COMPREHENSIVE INCOME (LOSS) (Tables)	12 Months Ended
	Sep. 30, 2018
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Comprehensive Income (Loss)	The amounts recognized in other comprehensive income (loss) were as follows: Years Ended September 30, 2018 2017 2016 Pre-tax Tax Net of tax Pre-tax Tax Net of tax Pre-tax Tax Net of tax Foreign currency translation adjustments $ 9,403 $ — $ 9,403 $ 10,667 $ — $ 10,667 $ 17,284 $ — $ 17,284 Pension and other defined benefit plans 24,081 (7,700 ) 16,381 14,160 (4,957 ) 9,203 (8,694 ) 3,043 (5,651 ) Cash flow hedge 900 (315 ) 585 1,370 (480 ) 890 (2,593 ) 907 (1,686 ) Total other comprehensive income (loss) $ 34,384 $ (8,015 ) $ 26,369 $ 26,197 $ (5,437 ) $ 20,760 $ 5,997 $ 3,950 $ 9,947 Total comprehensive income (loss) were as follows: For the Years Ended September 30, 2018 2017 2016 Net income (loss) $ 125,678 $ 14,912 $ 30,010 Other comprehensive income (loss), net of taxes 26,369 20,760 9,947 Comprehensive income (loss) $ 152,047 $ 35,672 $ 39,957
Accumulated other comprehensive income	The components of Accumulated other comprehensive income (loss) are as follows: At September 30, 2018 2017 Foreign currency translation $ (22,824 ) $ (32,227 ) Pension and other defined benefit plans (11,759 ) (28,140 ) Cash flow hedge 471 (114 ) $ (34,112 ) $ (60,481 )
Reclassification out of Accumulated Other Comprehensive Income	Amounts reclassified from accumulated other comprehensive income (loss) to income (loss) were as follows: For the Years Ended September 30, Gain (Loss) 2018 2017 2016 Pension amortization $ (1,397 ) $ (3,343 ) $ (2,375 ) Cash flow hedges 657 (1,458 ) (752 ) Total before tax (740 ) (4,801 ) (3,127 ) Tax 155 1,680 1,094 Net of tax $ (585 ) $ (3,121 ) $ (2,033 )

CONSOLIDATING GUARANTOR AND N_2

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Tables)	12 Months Ended
	Sep. 30, 2018
Consolidating Guarantor And Non Guarantor Financial Information [Abstract]
Condensed Balance Sheet	Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CURRENT ASSETS Cash and equivalents $ 15,976 $ 16,353 $ 37,429 $ — $ 69,758 Accounts receivable, net of allowances — 234,885 69,729 (24,105 ) 280,509 Contract costs and recognized income not yet billed, net of progress payments — 121,393 410 — 121,803 Inventories — 332,067 66,373 (81 ) 398,359 Prepaid and other current assets 12,179 21,313 6,168 2,461 42,121 Assets of discontinued operations not held for sale — — 324 — 324 Total Current Assets 28,155 726,011 180,433 (21,725 ) 912,874 PROPERTY, PLANT AND EQUIPMENT, net 936 299,920 41,636 — 342,492 GOODWILL 6,646 361,507 71,242 — 439,395 INTANGIBLE ASSETS, net 93 293,093 77,672 — 370,858 INTERCOMPANY RECEIVABLE 56,396 314,394 (121,445 ) (249,345 ) — EQUITY INVESTMENTS IN SUBSIDIARIES 1,528,932 968,330 3,347,894 (5,845,156 ) — OTHER ASSETS 8,651 15,942 374 (8,612 ) 16,355 ASSETS OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,916 — 2,916 Total Assets $ 1,629,809 $ 2,979,197 $ 3,600,722 $ (6,124,838 ) $ 2,084,890 CURRENT LIABILITIES Notes payable and current portion of long-term debt $ 2,276 $ 3,398 $ 7,337 $ — $ 13,011 Accounts payable and accrued liabilities 26,639 303,154 59,531 (16,474 ) 372,850 Liabilities of discontinued operations not held for sale — (22,327 ) 29,537 — 7,210 Total Current Liabilities 28,915 284,225 96,405 (16,474 ) 393,071 LONG-TERM DEBT, net 1,044,071 6,110 57,890 — 1,108,071 INTERCOMPANY PAYABLES 66,058 (77,760 ) 263,227 (251,525 ) — OTHER LIABILITIES 16,374 73,391 20,592 (3,647 ) 106,710 LIABILITIES OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,647 — 2,647 Total Liabilities 1,155,418 285,966 440,761 (271,646 ) 1,610,499 SHAREHOLDERS’ EQUITY 474,391 2,693,231 3,159,961 (5,853,192 ) 474,391 Total Liabilities and Shareholders’ Equity $ 1,629,809 $ 2,979,197 $ 3,600,722 $ (6,124,838 ) $ 2,084,890 CONDENSED CONSOLIDATING BALANCE SHEETS At September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CURRENT ASSETS Cash and equivalents 3,240 8,066 36,375 — 47,681 Accounts receivable, net of allowances — 168,731 59,929 (20,431 ) 208,229 Contract costs and recognized income not yet billed, net of progress payments — 131,383 279 — 131,662 Inventories, net — 246,605 52,759 73 299,437 Prepaid and other current assets 21,131 15,854 3,002 80 40,067 Assets of discontinued operations held for sale — 168,306 202,418 — 370,724 Assets of discontinued operations not held for sale — — 329 — 329 Total Current Assets 24,371 738,945 355,091 (20,278 ) 1,098,129 PROPERTY, PLANT AND EQUIPMENT, net 645 200,362 31,128 — 232,135 GOODWILL — 280,797 38,342 — 319,139 INTANGIBLE ASSETS, net 93 143,415 61,619 — 205,127 INTERCOMPANY RECEIVABLE 552,017 757,608 915,551 (2,225,176 ) — EQUITY INVESTMENTS IN SUBSIDIARIES 863,149 877,641 1,613,891 (3,354,681 ) — OTHER ASSETS 12,171 12,054 (1,002 ) (7,172 ) 16,051 ASSETS OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 2,960 — 2,960 Total Assets 1,452,446 3,010,822 3,017,580 (5,607,307 ) 1,873,541 CURRENT LIABILITIES Notes payable and current portion of long-term debt 2,854 1,471 6,753 — 11,078 Accounts payable and accrued liabilities 14,683 199,784 46,111 6,631 267,209 Liabilities of discontinued operations held for sale — 47,426 37,024 — 84,450 Liabilities of discontinued operations — — 8,342 — 8,342 Total Current Liabilities 17,537 248,681 98,230 6,631 371,079 LONG-TERM DEBT, net 903,609 6,044 58,427 — 968,080 INTERCOMPANY PAYABLES 84,068 1,259,413 854,518 (2,197,999 ) — OTHER LIABILITIES 48,424 76,036 14,135 (6,058 ) 132,537 LIABILITIES OF DISCONTINUED OPERATIONS NOT HELD FOR SALE — — 3,037 — 3,037 Total Liabilities 1,053,638 1,590,174 1,028,347 (2,197,426 ) 1,474,733 SHAREHOLDERS’ EQUITY 398,808 1,420,648 1,989,233 (3,409,881 ) 398,808 Total Liabilities and Shareholders’ Equity 1,452,446 3,010,822 3,017,580 (5,607,307 ) 1,873,541
Condensed Income Statement	Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,638,792 $ 367,149 $ (28,023 ) $ 1,977,918 Cost of goods and services — 1,232,019 245,687 (29,348 ) 1,448,358 Gross profit — 406,773 121,462 1,325 529,560 Selling, general and administrative expenses 38,691 303,856 90,933 (370 ) 433,110 Income (loss) from operations (38,691 ) 102,917 30,529 1,695 96,450 Other income (expense) Interest income (expense), net (23,911 ) (31,913 ) (8,047 ) — (63,871 ) Other, net (6,515 ) 120,670 (111,187 ) (1,737 ) 1,231 Total other income (expense) (30,426 ) 88,757 (119,234 ) (1,737 ) (62,640 ) Income (loss) before taxes (69,117 ) 191,674 (88,705 ) (42 ) 33,810 Provision (benefit) for income taxes (17,692 ) 9,546 8,743 (42 ) 555 Income (loss) before equity in net income of subsidiaries (51,425 ) 182,128 (97,448 ) — 33,255 Equity in net income (loss) of subsidiaries 177,103 (151,864 ) 182,128 (207,367 ) — Income (loss) from continuing operations 125,678 30,264 84,680 (207,367 ) 33,255 Income (loss) from operations of discontinued businesses — 119,981 — — 119,981 Provision (benefit) from income taxes — 27,558 — — 27,558 Income (loss) from discontinued operations — 92,423 — — 92,423 Net Income (loss) $ 125,678 $ 122,687 $ 84,680 $ (207,367 ) $ 125,678 Comprehensive income (loss) $ 152,047 $ 143,936 $ 81,389 $ (225,325 ) $ 152,047 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) For the Year Ended September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,284,189 $ 270,520 $ (29,712 ) $ 1,524,997 Cost of goods and services — 966,293 181,634 (31,046 ) 1,116,881 Gross profit — 317,896 88,886 1,334 408,116 Selling, general and administrative expenses 42,273 232,720 64,466 (370 ) 339,089 Restructuring and other related charges — — — — — Total operating expenses 42,273 232,720 64,466 (370 ) 339,089 Income (loss) from operations (42,273 ) 85,176 24,420 1,704 69,027 Other income (expense) Interest income (expense), net (13,804 ) (24,242 ) (13,403 ) — (51,449 ) Other, net 59 1,395 (630 ) (1,704 ) (880 ) Total other income (expense) (13,745 ) (22,847 ) (14,033 ) (1,704 ) (52,329 ) Income (loss) before taxes from continuing operations (56,018 ) 62,329 10,387 — 16,698 Provision (benefit) for income taxes (11,338 ) 24,560 (14,307 ) — (1,085 ) Income (loss) before equity in net income of subsidiaries (44,680 ) 37,769 24,694 — 17,783 Equity in net income (loss) of subsidiaries 59,592 (25,231 ) 37,770 (72,131 ) — Income (loss) from continuing operations 14,912 12,538 62,464 (72,131 ) 17,783 Income from operations of discontinued businesses — 16,827 5,449 — 22,276 Provision (benefit) from income taxes — 4,476 20,671 — 25,147 Loss from discontinued operations — 12,351 (15,222 ) — (2,871 ) Net income (loss) $ 14,912 $ 24,889 $ 47,242 $ (72,131 ) $ 14,912 Comprehensive income (loss) $ 35,672 $ 35,575 $ 38,337 $ (73,912 ) $ 35,672 CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) For the Year Ended September 30, 2016 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation Revenue $ — $ 1,277,241 $ 228,350 $ (28,556 ) $ 1,477,035 Cost of goods and services — 952,296 154,181 (30,135 ) 1,076,342 Gross profit — 324,945 74,169 1,579 400,693 Selling, general and administrative expenses 26,427 228,961 63,335 (370 ) 318,353 Restructuring and other related charges — 1,299 (1,299 ) — — Total operating expenses 26,427 230,260 62,036 (370 ) 318,353 Income (loss) from operations (26,427 ) 94,685 12,133 1,949 82,340 Other income (expense) Interest income (expense), net (12,549 ) (24,050 ) (13,278 ) — (49,877 ) Other, net 337 1,862 (500 ) (1,949 ) (250 ) Total other income (expense) (12,212 ) (22,188 ) (13,778 ) (1,949 ) (50,127 ) Income (loss) before taxes (38,639 ) 72,497 (1,645 ) — 32,213 Provision (benefit) for income taxes 4,964 29,445 (21,977 ) — 12,432 Income (loss) before equity in net income of subsidiaries (43,603 ) 43,052 20,332 — 19,781 Equity in net income (loss) of subsidiaries 73,613 (2,858 ) 43,052 (113,807 ) — Income (loss) from continuing operations $ 30,010 $ 40,194 $ 63,384 $ (113,807 ) $ 19,781 Income from operations of discontinued businesses — 15,625 5,327 — 20,952 Provision (benefit) from income taxes — 4,720 6,003 — 10,723 Income (loss) from discontinued operations — 10,905 (676 ) — 10,229 Net income (loss) $ 30,010 $ 51,099 $ 62,708 $ (113,807 ) $ 30,010 Comprehensive income (loss) $ 39,957 $ 44,391 $ 90,560 $ (134,951 ) $ 39,957
Condensed Cash Flow Statement	CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2018 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 125,678 $ 122,687 $ 84,680 $ (207,367 ) $ 125,678 Net (income) loss from discontinued operations — (92,423 ) — — (92,423 ) Net cash provided by (used in) operating activities 389,671 (405,174 ) 108,981 (27,032 ) 66,446 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (544 ) (41,531 ) (8,063 ) — (50,138 ) Acquired business, net of cash acquired (368,936 ) (4,843 ) (57,153 ) — (430,932 ) Intercompany distributions — — — — — Proceeds from sale of business — 474,727 — — 474,727 Proceeds from sale of assets — 62 601 — 663 Net cash provided by (used in) investing activities (369,480 ) 428,415 (64,615 ) — (5,680 ) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from issuance of common stock — — — — — Purchase of shares for treasury (45,605 ) — — — (45,605 ) Proceeds from long-term debt 411,623 2,125 29,310 — 443,058 Payments of long-term debt (269,478 ) (5,403 ) (26,112 ) — (300,993 ) Change in short-term borrowings — 144 — — 144 Financing costs (7,793 ) — — — (7,793 ) Tax effect from exercise/vesting of equity awards, net — — — — — Dividends paid (49,797 ) — — — (49,797 ) Other, net (46,405 ) 4,733 14,691 27,032 51 Net cash provided by (used in) financing activities (7,455 ) 1,599 17,889 27,032 39,065 CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash used in discontinued operations — (16,394 ) (62,533 ) — (78,927 ) Effect of exchange rate changes on cash and equivalents — (159 ) 1,332 — 1,173 NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS 12,736 8,287 1,054 — 22,077 CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 3,240 8,066 36,375 — 47,681 CASH AND EQUIVALENTS AT END OF PERIOD $ 15,976 $ 16,353 $ 37,429 $ — $ 69,758 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2017 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 14,912 $ 24,889 $ 47,242 $ (72,131 ) $ 14,912 Net (income) loss from discontinued operations — (12,351 ) 15,222 — 2,871 Net cash provided by operating activities (10,771 ) 56,320 3,602 — 49,151 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (15 ) (27,902 ) (7,020 ) — (34,937 ) Acquired business, net of cash acquired — — (34,719 ) — (34,719 ) Purchase of securities (1,824 ) — — — (1,824 ) Proceeds from sale of property, plant and equipment — 144 (1 ) — 143 Net cash used in investing activities (1,839 ) (27,758 ) (41,740 ) — (71,337 ) CASH FLOWS FROM FINANCING ACTIVITIES: Purchase of shares for treasury (15,841 ) — — — (15,841 ) Proceeds from long-term debt 201,124 — 32,319 — 233,443 Payments of long-term debt (149,109 ) (1,282 ) (20,063 ) — (170,454 ) Share premium payment on settled debt (24,997 ) — — — (24,997 ) Change in short-term borrowings — — — — — Financing costs (1,548 ) — — — (1,548 ) Purchase of ESOP shares (10,908 ) — — — (10,908 ) Dividends paid (10,325 ) — — — (10,325 ) Other, net 20,937 (34,806 ) 13,799 — (70 ) Net cash used in financing activities 9,333 (36,088 ) 26,055 — (700 ) CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash provided by (used in) discontinued operations — (12,100 ) 9,950 — (2,150 ) Effect of exchange rate changes on cash and equivalents — — 164 — 164 NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS (3,277 ) (19,626 ) (1,969 ) — (24,872 ) CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 6,517 27,692 38,344 — 72,553 CASH AND EQUIVALENTS AT END OF PERIOD $ 3,240 $ 8,066 $ 36,375 $ — $ 47,681 CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended September 30, 2016 Parent Company Guarantor Companies Non-Guarantor Companies Elimination Consolidation CASH FLOWS FROM OPERATING ACTIVITIES: Net income (loss) $ 30,010 $ 51,099 $ 62,708 $ (113,807 ) $ 30,010 Net income (loss) from discontinued operations — 10,905 (676 ) — 10,229 Net cash provided by (used in) operating activities (11,879 ) 87,252 4,745 — 80,118 CASH FLOWS FROM INVESTING ACTIVITIES: Acquisition of property, plant and equipment (259 ) (62,176 ) 3,159 — (59,276 ) Intercompany distributions — (2,726 ) (1,744 ) — (4,470 ) Proceeds from sale of property, plant and equipment — 763 7 — 770 Investment purchases 715 — — — 715 Net cash provided by (used in) investing activities 456 (64,139 ) 1,422 — (62,261 ) CASH FLOWS FROM FINANCING ACTIVITIES: Purchase of shares for treasury (65,307 ) — — — (65,307 ) Proceeds from long-term debt 271,340 2,311 28,711 — 302,362 Payments of long-term debt (177,513 ) (1,237 ) (29,764 ) — (208,514 ) Change in short-term borrowings — — — — — Financing costs (4,277 ) — (107 ) — (4,384 ) Tax effect from exercise/vesting of equity awards, net — — — — — Dividends paid (8,798 ) — — — (8,798 ) Other, net 55 (1,926 ) 1,926 — 55 Net cash provided by (used in) financing activities 15,500 (852 ) 766 — 15,414 CASH FLOWS FROM DISCONTINUED OPERATIONS: Net cash provided by (used in) discontinued operations — (5,241 ) (8,364 ) — (13,605 ) Effect of exchange rate changes on cash and equivalents — — 886 — 886 NET DECREASE IN CASH AND EQUIVALENTS 4,077 17,020 (545 ) — 20,552 CASH AND EQUIVALENTS AT BEGINNING OF PERIOD 2,440 10,672 38,889 — 52,001 CASH AND EQUIVALENTS AT END OF PERIOD $ 6,517 $ 27,692 $ 38,344 $ — $ 72,553

DESCRIPTION OF BUSINESS AND S_3

DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ / shares in Units, $ in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2018AUD ($)componentsegment	Sep. 30, 2018USD ($)componentsegment$ / shares	Sep. 30, 2018CAD ($)componentsegment	Sep. 30, 2017AUD ($)	Sep. 30, 2017USD ($)$ / shares	Sep. 30, 2017CAD ($)	Sep. 30, 2016USD ($)	Nov. 16, 2017USD ($)	Nov. 15, 2017USD ($)
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Number of operating segments | segment	2	2	2
Environmental exit costs, costs accrued to date					$ 5,700,000
Cash in non U.S. bank accounts		$ 24,900,000			26,500,000
Fair value of insurance contracts		3,032,000
Proceeds from sale of trading securities		4,126,000					$ 715,000
Contracts revenue		$ 1,977,918,000	$ 700		$ 1,524,997,000	$ 4,690	1,477,035,000
Contracts weighted average rate price (in Dollars per share) | $ / shares		$ 1.29			$ 1.25
Accumulated other comprehensive income (loss), foreign currency translation adjustment, net of tax		$ 9,403,000			$ 10,667,000
Foreign currency transaction gain (loss), realized		(7,000)			378,000
Share-based compensation, excess tax benefit, amount		2,193,000
Defined benefit plan, fair value of plan assets		$ 150,634,000			150,822,000
Contract period	1 year	1 year	1 year
Income (loss) from operations		$ 96,450,000			69,027,000		82,340,000
Provision for loss on contracts		12,200,000
Customer program reserves and cash discounts netted against accounts receivable		15,530,000			11,249,000
Costs in excess of billings, noncurrent		29,500,000			20,100,000
Unbilled contracts receivable		400,000			2,850,000
Depreciation, depletion and amortization, nonproduction		46,733,000			41,220,000		39,734,000
Accumulated capitalized interest costs		2,896,000			4,891,000		3,956,000
Original cost of fully depreciated property plant and equipment		$ 213,501,000
Description of fair value calculation	Griffon used five year projections and a 3.0% terminal value to which discount rates between 9% and 10% were applied to calculate each unit’s fair value.	Griffon used five year projections and a 3.0% terminal value to which discount rates between 9% and 10% were applied to calculate each unit’s fair value.	Griffon used five year projections and a 3.0% terminal value to which discount rates between 9% and 10% were applied to calculate each unit’s fair value.
Fair value projections	5 years	5 years	5 years
Fair value terminal value	3.00%	3.00%	3.00%
Goodwill, impairment loss		$ 0			0		0
Unrecognized tax benefits		4,519,000			4,825,000		4,709,000
Research and development arrangement, contract to perform for others, costs incurred, gross		15,400,000			17,700,000		18,000,000
Net cash used in financing activities		39,065,000			(700,000)		$ 15,414,000
Accumulated other comprehensive loss		$ (34,112,000)			$ (60,481,000)
U.S. Federal income tax provision (benefit) rate	24.50%	24.50%	24.50%	35.00%	35.00%	35.00%	35.00%
Selling, general and administrative expenses		$ 433,110,000			$ 339,089,000		$ 318,353,000
Home and Building Products (HBP) [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Number of operating segments | segment	2	2	2
Home & Building Products [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Number of components | component	2	2	2
Other Income [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Trading securities, realized loss		$ 1,251,000					13,000
Selling, general and administrative expenses [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Depreciation		$ 16,306,000			12,995,000		11,721,000
U.S. Government [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Percentage of consolidated accounts receivable	8.00%	8.00%	8.00%
Home Depot [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Percentage of consolidated accounts receivable	20.00%	20.00%	20.00%
Contracts accounted for under percentage of completion [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Income (loss) from operations		$ 1,400,000			$ 600,000		(700,000)
Designated as hedging instrument [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Contracts revenue	$ 12,000			$ 14,500
Contracts weighted average rate price (in Dollars per share) | $ / shares		$ 1.38			$ 1.28
Accumulated other comprehensive income (loss), foreign currency translation adjustment, before tax		$ 443,000			$ 175,000
Accumulated other comprehensive income (loss), foreign currency translation adjustment, net of tax		288,000			114,000
Gain (loss) on hedging activity		657,000			(1,458,000)
Level 2 [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Defined benefit plan, fair value of plan assets		68,114,000			68,723,000
Level 2 [Member] | Estimate of fair value measurement [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Trading securities		2,644,000			3,352,000
Level 2 [Member] | Portion at other than fair value measurement [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Trading securities		2,086,000			1,000,000
Senior notes [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Long-term debt, fair value		$ 990,000,000
Maximum [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Maturity period of highly liquid investments	3 months	3 months	3 months
Contracts expiration days	92 days	92 days	92 days
Fair value discount rates	9.50%	9.50%	9.50%
Finite-lived intangible asset, useful life	25 years	25 years	25 years
Maximum [Member] | Building and building improvements [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Property, plant and equipment, useful life	40 years	40 years	40 years
Maximum [Member] | Machinery and equipment [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Property, plant and equipment, useful life	15 years	15 years	15 years
Minimum [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Contracts expiration days	31 days	31 days	31 days
Fair value discount rates	7.00%	7.00%	7.00%
Finite-lived intangible asset, useful life	8 years	8 years	8 years
Minimum [Member] | Building and building improvements [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Property, plant and equipment, useful life	25 years	25 years	25 years
Minimum [Member] | Machinery and equipment [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Property, plant and equipment, useful life	2 years	2 years	2 years
Canadian Dollar Forward Contracts [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member] | Other Income [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Gain (loss) on sale of derivatives		$ (161,000)			200,000
Canadian Dollar Forward Contracts [Member] | Maximum [Member] | Not Designated as Hedging Instrument [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Foreign currency contracts duration	358 days	358 days	358 days
Canadian Dollar Forward Contracts [Member] | Minimum [Member] | Not Designated as Hedging Instrument [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Foreign currency contracts duration	30 days	30 days	30 days
New Accounting Pronouncement, Early Adoption, Effect [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Share-based compensation, excess tax benefit, amount		$ 1,299,000			4,440,000
Accounting Standards Update 2016-09, Statutory Tax Withholding Component [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Net cash provided by operating activities		2,291,000
Net cash used in financing activities		2,291,000
Discontinued Operations, Held-for-sale [Member] | Plastics [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Disposal group, including discontinued operation, consideration								$ 475,000,000	$ 475,000,000
Foreign currency translation adjustments [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Accumulated other comprehensive loss		(22,824,000)			(32,227,000)
Shipping and Handling [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Selling, general and administrative expenses		59,600,000			32,500,000		30,600,000
Advertising [Member]
DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) [Line Items]
Selling, general and administrative expenses		$ 21,000,000			$ 22,000,000		$ 23,000,000

ACQUISITIONS (Details)

ACQUISITIONS (Details) £ in Thousands, $ in Thousands, $ in Thousands

Jun. 04, 2018USD ($)

Feb. 13, 2018GBP (£)

Feb. 13, 2018USD ($)

Nov. 06, 2017USD ($)

Oct. 02, 2017USD ($)

Sep. 29, 2017AUD ($)

Sep. 29, 2017USD ($)

Jul. 31, 2017GBP (£)

Jul. 31, 2017USD ($)

Dec. 30, 2016AUD ($)

Dec. 30, 2016USD ($)

Feb. 14, 2016USD ($)

Oct. 31, 2018USD ($)

Dec. 31, 2015USD ($)

Jun. 30, 2018USD ($)

Mar. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Sep. 30, 2018USD ($)

Sep. 30, 2017USD ($)

Sep. 30, 2016

Jul. 31, 2017USD ($)

May 18, 2016

Dec. 31, 2014

Nov. 30, 2014

Feb. 27, 2014

ACQUISITIONS (Details) [Line Items]

Acquisition related costs

$ 2,320

$ 378

$ 2,348

$ 6,145

Effective tax provision (benefit) rate

1.60%

(6.50%)

38.60%

Harper Brush Works [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 4,383

Intangible assets

$ 2,300

ClosetMaid LLC [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 185,700

Definite-lived intangibles

26,840

Intangible assets

74,580

Accounts receivable (1)

$ 32,234

Restructuring charges adjustments

$ (900)

Effective tax provision (benefit) rate

39.70%

Tuscan Landscape Group Pty LTS [Member]

ACQUISITIONS (Details) [Line Items]

Intangible assets

$ 3,900

$ 6,400

Accounts receivable (1)

7,900

Tuscan Landscape Group Pty LTS [Member] | AMES Australia [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 22,250

$ 18,000

La Hacienda Limited [Member]

ACQUISITIONS (Details) [Line Items]

Intangible assets | £

£ 3,100

Accounts receivable (1) | £

4,200

La Hacienda Limited [Member] | The AMES Companies, Inc. [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

9,175

$ 11,400

Contingent consideration

£ 790

$ 600

Hills Home Living [Member] | AMES Australia [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

8,400

$ 6,051

Nylex Plastics Pty Ltd. [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 2,452

Nylex Plastics Pty Ltd. [Member] | AMES Australia [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 1,744

Cornell Cookson [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

$ 180,000

Definite-lived intangibles

14,100

Intangible assets

67,600

Accounts receivable (1)

30,400

Working capital adjustment

$ 12,426

Kelkay [Member]

ACQUISITIONS (Details) [Line Items]

Business combination, consideration transferred

£ 40,452

$ 56,118

Contingent consideration

7,000

Land acquired

8,241

Accounts receivable and inventory

8,894

Mahindra Telephonics Integrated Systems [Member]

ACQUISITIONS (Details) [Line Items]

Payments to Acquire Interest in Joint Venture

$ 2,726

Ownership percentage

49.00%

26.00%

Subsequent Event [Member] | Cornell Cookson [Member]

ACQUISITIONS (Details) [Line Items]

Payments to acquire businesses

$ 9,219

Selling, general and administrative expenses [Member] | ClosetMaid LLC [Member]

ACQUISITIONS (Details) [Line Items]

Acquisition related costs

$ 6,097

Cost of Sales [Member] | ClosetMaid LLC [Member]

ACQUISITIONS (Details) [Line Items]

Acquisition related costs

$ 1,500

Senior Notes Two Thousand Twenty Two [Member]

ACQUISITIONS (Details) [Line Items]

Stated percentage

5.25%

5.25%

5.25%

Senior Notes Two Thousand Twenty Two [Member] | ClosetMaid LLC [Member]

ACQUISITIONS (Details) [Line Items]

Stated percentage

5.25%

Senior note due 2022 [Member] | Senior notes [Member]

ACQUISITIONS (Details) [Line Items]

Proceeds from issuance of debt

$ 275,000

Stated percentage

5.25%

Senior note due 2022 [Member] | Senior notes [Member] | ClosetMaid LLC [Member]

ACQUISITIONS (Details) [Line Items]

Proceeds from issuance of debt

$ 275,000

Senior note due 2022 [Member] | Senior notes [Member] | Cornell Cookson [Member]

ACQUISITIONS (Details) [Line Items]

Proceeds from issuance of debt

$ 9,617

Trade Names [Member] | Kelkay [Member]

ACQUISITIONS (Details) [Line Items]

Definite-lived intangibles

19,000

Customer relationships [Member] | Kelkay [Member]

ACQUISITIONS (Details) [Line Items]

Definite-lived intangibles

$ 6,640

ACQUISITIONS (Details) - Acquis

ACQUISITIONS (Details) - Acquisition of CornellCookson, Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 04, 2018	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Goodwill	$ 439,395		$ 319,139	$ 306,163
Cornell Cookson [Member]
Business Acquisition [Line Items]
Accounts receivable		$ 30,400
Inventories		12,336
Property, plant and equipment		49,426
Goodwill		42,883
Intangible assets		67,600
Other current and non-current assets		2,648
Total assets acquired		205,293
Accounts payable and accrued liabilities		12,207
Long-term liabilities		660
Total liabilities assumed		12,867
Total		192,426
Receivables gross		30,818
Allowance for accounts receivable		418
Inventory, gross		13,433
Inventory valuation reserves		$ 1,098

ACQUISITIONS (Details) - Schedu

ACQUISITIONS (Details) - Schedule of Intangible Assets Acquired in Cornell Cookson Acquisition (Details) - USD ($) $ in Thousands	Jun. 04, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Goodwill		$ 439,395	$ 319,139	$ 306,163
Cornell Cookson [Member]
Business Acquisition [Line Items]
Goodwill	$ 42,883
Indefinite-lived intangibles	53,500
Definite-lived intangibles	$ 14,100
Amortization Period (Years)	12 years
Total goodwill and intangible assets	$ 110,483

ACQUISITIONS (Details) - Pro Fo

ACQUISITIONS (Details) - Pro Forma $ in Thousands	12 Months Ended
	Sep. 30, 2017USD ($)
Business Combinations [Abstract]
Revenue	$ 1,823,497
Income from continuing operations	$ 15,070

ACQUISITIONS (Details) - Summar

ACQUISITIONS (Details) - Summary of Fair Values of Assets Acquired - USD ($) $ in Thousands	Sep. 30, 2018	Oct. 02, 2017	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Goodwill	$ 439,395		$ 319,139	$ 306,163
ClosetMaid LLC [Member]
Business Acquisition [Line Items]
Accounts receivable (1)		$ 32,234
Inventories (2)		28,411
Property, plant and equipment		47,464
Goodwill		70,159
Intangible assets		74,580
Other current and non-current assets		3,852
Total assets acquired		256,700
Accounts payable and accrued liabilities		(68,251)
Long-term liabilities		2,720
Total liabilities assumed		(70,971)
Total		185,729
Receivables gross		32,298
Allowance for accounts receivable		332
Inventory step-up		$ 1,500

ACQUISITIONS (Details) - Summ_2

ACQUISITIONS (Details) - Summary of Goodwill and Intangible Asset Classifications - USD ($) $ in Thousands	Oct. 02, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Goodwill		$ 439,395	$ 319,139	$ 306,163
ClosetMaid LLC [Member]
Business Acquisition [Line Items]
Goodwill	$ 70,159
Indefinite-lived intangibles	47,740
Definite-lived intangibles	26,840
Total goodwill and intangible assets	$ 144,739
Amortization Period (Years)	21 years

INVENTORIES (Details) - Summary

INVENTORIES (Details) - Summary of Inventories stated at lower cost - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 97,645	$ 67,990
Work in process	83,578	78,846
Finished goods	217,136	152,601
Total	$ 398,359	$ 299,437

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT (Details) - Summary of property plant and equipment - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Property Plant And Equipment Gross	$ 725,282	$ 576,977
Accumulated depreciation and amortization	(382,790)	(344,842)
Total	342,492	232,135
Land, building and building improvements [Member]
Property, Plant and Equipment [Line Items]
Property Plant And Equipment Gross	130,296	71,764
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property Plant And Equipment Gross	544,875	462,173
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property Plant And Equipment Gross	$ 50,111	$ 43,040

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLES (Details) - Summary of changes in carrying value of goodwill - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Goodwill [Roll Forward]
Goodwill	$ 319,139	$ 306,163
Goodwill from acquisitions	119,907	12,417
Foreign currency translation adjustments	349	559
Goodwill	439,395	319,139
Home & Building Products [Member]
Goodwill [Roll Forward]
Goodwill	300,594	287,618
Goodwill from acquisitions	119,907	12,417
Foreign currency translation adjustments	349	559
Goodwill	420,850	300,594
Telephonics [Member]
Goodwill [Roll Forward]
Goodwill	18,545	18,545
Goodwill from acquisitions	0	0
Foreign currency translation adjustments	0	0
Goodwill	$ 18,545	$ 18,545

GOODWILL AND OTHER INTANGIBLE_3

GOODWILL AND OTHER INTANGIBLES (Details) - Summary of gross carrying value and accumulated amortization of intangible assets - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
GOODWILL AND OTHER INTANGIBLES (Details) - Summary of gross carrying value and accumulated amortization of intangible assets [Line Items]
Gross Carrying Amount	$ 205,035	$ 158,218
Trademarks	221,883	95,049
Total intangible assets	426,918	253,267
Accumulated Amortization	56,060	48,140
Customer relationships [Member]
GOODWILL AND OTHER INTANGIBLES (Details) - Summary of gross carrying value and accumulated amortization of intangible assets [Line Items]
Gross Carrying Amount	186,031	152,025
Accumulated Amortization	$ 49,822	43,421
Average Life (Years)	23 years
Unpatented technology [Member]
GOODWILL AND OTHER INTANGIBLES (Details) - Summary of gross carrying value and accumulated amortization of intangible assets [Line Items]
Gross Carrying Amount	$ 19,004	6,193
Accumulated Amortization	$ 6,238	$ 4,719
Average Life (Years)	13 years

GOODWILL AND OTHER INTANGIBLE_4

GOODWILL AND OTHER INTANGIBLES (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 9,070	$ 6,658	$ 6,608
Amortization expense estimated for 2018	9,285
Amortization expense estimated for 2019	8,825
Amortization expense estimated for 2020	8,825
Amortization expense estimated for 2021	8,825
Amortization expense estimated for 2022	8,746
Amortization expense estimated thereafter	$ 104,469

DISCONTINUED OPERATIONS (Detail

DISCONTINUED OPERATIONS (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2008unit	Nov. 16, 2017USD ($)	Nov. 15, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of units sold | unit				11
Number of closed units | unit				1
Number of merged units | unit				2
Environmental exit costs, costs accrued to date		$ 5,700
Plastics [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group, including discontinued operation, consideration					$ 475,000	$ 475,000
Gain on sale of business	$ 112,964	$ 0	$ 0
Gain on sale of business net of tax	81,041
Stay and transaction bonuses and other accrued liabilities	$ 9,858

DISCONTINUED OPERATIONS - Incom

DISCONTINUED OPERATIONS - Income Statement Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations	$ 92,423	$ (2,871)	$ 10,229
Plastics [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	166,262	460,914	480,126
Cost of goods and services	132,100	389,416	407,385
Gross profit	34,162	71,498	72,741
Selling, general and administrative expenses	26,303	43,518	45,673
Restructuring charges	0	0	5,900
Total operating expenses	26,303	43,518	51,573
Income from discontinued operations	7,859	27,980	21,168
Gain on sale of business	112,964	0	0
Interest expense, net	(155)	(63)	(1,234)
Other, net	(687)	59	1,018
Total other income (expense)	112,122	(4)	(216)
Income (loss) from discontinued operations	$ 119,981	$ 27,976	$ 20,952

DISCONTINUED OPERATIONS - Balan

DISCONTINUED OPERATIONS - Balance Sheets Information (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
OTHER ASSETS	$ 2,916	$ 2,960
Total Assets Held for Sale	3,240	374,013	$ 364,911
OTHER LIABILITIES	$ 2,647	3,037
Plastics [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable, net		51,768
Inventories, net		45,742
Prepaid and other current assets		11,000
PROPERTY, PLANT AND EQUIPMENT, net		185,940
GOODWILL		57,087
INTANGIBLE ASSETS, net		12,298
OTHER ASSETS		6,889
Total Assets Held for Sale		370,724
Notes payable and current portion of long-term debt		11,163
Accounts payable		36,619
Accrued liabilities		14,553
LONG-TERM DEBT, net		10,549
OTHER LIABILITIES		11,566
Total Liabilities Held for Sale		$ 84,450

DISCONTINUED OPERATIONS (Deta_2

DISCONTINUED OPERATIONS (Details) - Summary of discontinued operations - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Assets of discontinued operations:
Assets of discontinued operations not held for sale	$ 324	$ 329
ASSETS OF DISCONTINUED OPERATIONS	2,916	2,960
Liabilities of discontinued operations:
Liabilities of discontinued operations	7,210	8,342
LIABILITIES OF DISCONTINUED OPERATIONS	2,647	3,037
Discontinued Operations [Member]
Assets of discontinued operations:
Assets of discontinued operations not held for sale	324	329
ASSETS OF DISCONTINUED OPERATIONS	2,916	2,960
Total assets of discontinued operations	3,240	3,289
Liabilities of discontinued operations:
Liabilities of discontinued operations	7,210	8,342
LIABILITIES OF DISCONTINUED OPERATIONS	$ 2,648	3,037
Total liabilities of discontinued operations		$ 11,379

ACCRUED LIABILITIES (Details) -

ACCRUED LIABILITIES (Details) - Schedule of accrued liabilities - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Payables and Accruals [Abstract]
Compensation	$ 50,251	$ 37,692
Interest	4,776	3,671
Warranties and rebates	11,227	6,236
Insurance	25,329	12,216
Rent, utilities and freight	4,830	2,149
Income and other taxes	8,016	6,291
Marketing and advertising	3,685	1,859
Acquisition related accruals	17,448	0
Other	13,630	13,144
Total	$ 139,192	$ 83,258

WARRANTY LIABILITY (Details)

WARRANTY LIABILITY (Details)	12 Months Ended
	Sep. 30, 2018
Telephonics [Member] | Minimum [Member]
WARRANTY LIABILITY (Details) [Line Items]
Product warranty period	1 year
Telephonics [Member] | Maximum [Member]
WARRANTY LIABILITY (Details) [Line Items]
Product warranty period	2 years
Clopay Plastic Products Company Inc. [Member] | Minimum [Member]
WARRANTY LIABILITY (Details) [Line Items]
Product warranty period	1 year
Clopay Plastic Products Company Inc. [Member] | Maximum [Member]
WARRANTY LIABILITY (Details) [Line Items]
Product warranty period	10 years
AMES [Member]
WARRANTY LIABILITY (Details) [Line Items]
Product warranty period	90 days

WARRANTY LIABILITY (Details) -

WARRANTY LIABILITY (Details) - Summary of changes in warrant liability included in Accrued liabilities - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance, beginning of period	$ 6,236	$ 6,322
Warranties issued and changes in estimated pre-existing warranties	8,770	6,393
Actual warranty costs incurred	(7,948)	(6,479)
Other warranty liabilities assumed from acquisitions	1,116	0
Balance, end of period	$ 8,174	$ 6,236

NOTES PAYABLE, CAPITALIZED LE_3

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of net minimum payments on capitalized leases $ in Thousands	Sep. 30, 2018USD ($)
Debt Disclosure [Abstract]
Total minimum lease payments	$ 10,586
Less amount representing interest payments	(812)
Present value of net minimum lease payments	9,774
Current portion	(3,579)
Capitalized lease obligation, less current portion	$ 6,195

NOTES PAYABLE, CAPITALIZED LE_4

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) $ / shares in Units, £ in Thousands

Sep. 30, 2018AUD ($)

Apr. 16, 2018USD ($)$ / shares

Oct. 02, 2017USD ($)

Jun. 30, 2017USD ($)

Jan. 17, 2017USD ($)shares

Jul. 31, 2016AUD ($)loan

Jul. 14, 2016USD ($)

Mar. 13, 2015

Feb. 27, 2014USD ($)

Jul. 31, 2018GBP (£)

Aug. 31, 2016USD ($)

Jul. 31, 2016AUD ($)loan

Nov. 30, 2012CAD ($)

Oct. 31, 2006USD ($)

Jun. 30, 2018

Sep. 30, 2018USD ($)$ / shares

Sep. 30, 2017USD ($)$ / sharesshares

Sep. 30, 2016USD ($)$ / shares

Sep. 30, 2018USD ($)

Sep. 30, 2018CAD ($)

Feb. 05, 2018USD ($)

Dec. 18, 2017USD ($)

Sep. 30, 2017AUD ($)

Sep. 30, 2017USD ($)

Mar. 31, 2017AUD ($)

Dec. 31, 2016AUD ($)

Nov. 30, 2016AUD ($)

Jul. 20, 2016USD ($)

May 18, 2016USD ($)

Mar. 31, 2016USD ($)property

Mar. 22, 2016USD ($)

Mar. 21, 2016USD ($)

Sep. 30, 2015USD ($)

Jun. 18, 2014USD ($)

Dec. 21, 2009USD ($)

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument exercised period

5 years

Minimum payments under capital leases for 2018

$ 4,242,000

Minimum payments under capital leases for 2019

3,764,000

Minimum payments under capital leases for 2020

2,102,000

Minimum payments under capital leases for 2021

443,000

Minimum payments under capital leases for 2022

35,000

Minimum payments under capital leases thereafter

0

Capital leased assets, gross

41,742,000

$ 19,238,000

Capital leases, lessee balance sheet, assets by major class, accumulated depreciation

31,969,000

11,831,000

Deferred interest charges

80,000

105,000

Amortization

$ 3,514,000

$ 1,683,000

$ 1,628,000

Proceeds from long-term debt

$ 443,058,000

$ 233,443,000

302,362,000

Payments to acquire buildings

$ 10,000,000

Capital lease maturity year

2,022

Long-term debt, percentage bearing fixed interest, percentage rate

5.00%

Minimum payments under debt agreements for 2018

13,011,000

Minimum payments under debt agreements for 2019

43,330,000

Minimum payment under debt engagement for 2020

6,802,000

Minimum payments under debt agreements for 2021

5,233,000

Minimum payments under debt agreements for 2022

4,827,000

Minimum payments under debt agreements thereafter

1,061,489,000

Debt instrument, face amount

$ 35,092,000

Capitalized fees & expenses

14,830,000

12,066,000

Underwriting fees and other expense capitalized

$ 13,329,000

Maximum percentage of equity interest of subsidiaries borrowings guaranteed

65.00%

Line of credit facility, amount outstanding

$ 0

Debt instrument, basis spread on variable rate

1.30%

Outstanding debt

1,121,082,000

979,158,000

Long-term debt, gross

1,134,692,000

992,401,000

Amount of line note available to purchase common stock in open market

$ 10,908,000

Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares

$ 0.28

$ 0.24

$ 0.20

Stock issued during period, shares, ESOP | shares

621,875

Debt instrument, interest rate during period

5.55%

Issuance of treasury stock in settlement of convertible debt

$ 48,858,000

Term Loan [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid | £

£ 7,000

Term Loan [Member] | Ames UK [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount | £

14,000

Debt instrument, periodic payment, principal | £

£ 350

Long-term Line of Credit, Noncurrent

23,987,000

Revolver due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, remaining borrowing capacity

310,377,000

Revolving Credit Facility [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

2.25%

1.50%

Revolving Credit Facility [Member] | Ames UK [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount | £

£ 5,000

Letter Of Credit Subfacility [Member] | Revolver due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, current borrowing capacity

$ 50,000

Line of credit facility, amount outstanding

14,623,000

Multicurrency Subfacility [Member] | Revolver due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, current borrowing capacity

100,000,000

Margin Rate [Member] | Revolver due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, interest rate during period

1.75%

LIBOR Rate [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, interest rate during period

2.75%

Convert. debt due 2017 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 100,000,000

Stated percentage

4.00%

ESOP Loans [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Stock issued during period, value, ESOP

$ 10,908,000

ESOP, weighted average purchase price of shares purchased (in Dollars per share) | $ / shares

$ 17.54

Revolving Facility, June 2017 [Member] | Revolving Credit Facility [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, amount outstanding

$ 11,000,000

7,951,000

Maximum borrowing capacity

$ 10,000,000

$ 10,000,000

$ 20,000

$ 10,000,000

Secured Debt [Member] | Term Loan 1 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Repayments of Debt

$ 5,705,000

Capital lease - real estate [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Proceeds from long-term debt

$ 14,290,000

Capitalized fees & expenses

80,000

[1]

105,000

[2]

Outstanding debt

7,423,000

5,207,000

[2]

Long-term debt, gross

$ 7,503,000

[1]

$ 5,312,000

[2]

Debt instrument, interest rate during period

[2]

5.50%

5.50%

Debt instrument, interest rate at period end

5.00%

[1]

5.00%

[1]

5.00%

[1]

5.00%

[2]

5.00%

[2]

Senior notes [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 275,000,000

$ 125,000,000

Senior notes [Member] | Level 1 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Notes payable, fair value disclosure

$ 990,000,000

Senior notes [Member] | Reissued Senior Notes [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 725,000,000

Senior notes [Member] | Senior Notes due 2022, May 2016 Add-On Issuance [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 275,000,000

$ 125,000,000

Issuance price, percentage

101.00%

98.76%

Senior notes [Member] | Senior note due 2022 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 600,000,000

Unamortized debt issuance expense

14,830,000

Stated percentage

5.25%

Proceeds from issuance of debt

$ 275,000,000

Outstanding debt

1,000,000,000

Senior notes [Member] | Senior note due 2022 [Member] | Senior notes due 2018 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 550,000,000

Stated percentage

7.125%

Payment of tender offer premium

$ 31,530,000

Debt instrument, periodic payment, interest

$ 16,716,000

Senior note due 2022 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

12,968,000

[3]

$ 8,472,000

Outstanding debt

988,252,000

Long-term debt, gross

[3]

$ 1,000,000,000

Debt instrument, interest rate during period

5.66%

[3]

5.48%

Debt instrument, interest rate at period end

[3]

5.25%

5.25%

5.25%

Senior Notes Two Thousand Twenty Two [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 600,000,000

Stated percentage

5.25%

5.25%

5.25%

Original debt, amount

$ 125,000,000

Convertible Notes 2017 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt Conversion, Converted Instrument, Amount

$ 173,855,000

Debt conversion, converted instrument, cash received

125,000,000

Issuance of treasury stock in settlement of convertible debt

$ 48,858,000

Converted instrument, shares issued | shares

1,954,993,000

Senior notes due 2018 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

[3]

$ 9,220,000

Outstanding debt

[3]

714,603,000

Long-term debt, gross

[3]

$ 725,000,000

Debt instrument, interest rate at period end

[3]

5.25%

5.25%

Revolver due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

$ 1,413,000

[4]

$ 1,951,000

[3]

Line of credit facility, current borrowing capacity

$ 350,000

$ 250,000,000

Outstanding debt

23,587,000

[4]

142,265,000

[3]

Long-term debt, gross

25,000,000

[4]

144,216,000

[3]

Real estate mortgages [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 8,000,000

$ 32,280,000

Number of secured properties | property

4

Capitalized fees & expenses

[5]

320,000

Debt instrument, description of variable rate basis

LIBOR plus 2.75%

Debt instrument, basis spread on variable rate

1.50%

Outstanding debt

[5]

23,322,000

Long-term debt, gross

[5]

23,642,000

Debt instrument, interest rate during period

[5]

3.30%

2.60%

2.20%

ESOP Loans [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

186,000

[2]

310,000

[6]

Debt instrument, description of variable rate basis

The loan bears interest at a) LIBOR plus 2.38% or b) the lender’s prime rate, at Griffon’s option.

Outstanding debt

34,508,000

42,365,000

[6]

Long-term debt, gross

34,694,000

[2]

42,675,000

[6]

Debt instrument, periodic payment, principal

$ 569,000

Debt instrument, interest rate during period

[6]

6.30%

4.20%

3.10%

Revolver due 2013 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, description of variable rate basis

The revolving credit facility accrues interest at EURIBOR plus 2.20% per annum.

Non U.S. term loans [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

148,000

[7]

108,000

[1]

Outstanding debt

53,385,000

35,835,000

[1]

Long-term debt, gross

53,533,000

[7]

35,943,000

[1]

Non U.S. lines of credit [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Capitalized fees & expenses

[1]

16,000

31,000

Line of credit facility, remaining borrowing capacity

11,498,000

$ 15,000,000

Outstanding debt

7,935,000

9,371,000

[1]

Long-term debt, gross

[1]

$ 7,951,000

$ 9,402,000

Proceeds from long-term lines of credit (in Euro)

$ 15,000,000

$ 11,498

Line of credit facility, interest rate description

The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum.

Non U.S. lines of credit [Member] | LIBOR Rate [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, interest rate at period end

3.70%

3.70%

3.70%

Non U.S. lines of credit [Member] | Bankers Acceptance Rate [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Line of credit facility, interest rate at period end

3.24%

3.24%

3.24%

Medium-term Notes [Member] | Term Loan Due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount

$ 30,000,000

$ 30,000,000

Number of loans refinanced with new debt instrument | loan

2

2

Line of credit facility, amount outstanding

$ 40,875,000

$ 29,546,000

Debt instrument, periodic payment, principal

$ 1,250,000

Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid

$ 37,125,000

$ 37,125,000

Term Loan May 2014 [Member] | Northcote Holdings Pty. Ltd [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Maximum borrowing capacity increase

$ 15,000,000

$ 5,000,000

Mortgages [Member] | Ames UK [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, face amount | £

4,000

Debt instrument, periodic payment, principal | £

83

Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid | £

£ 2,333

London Interbank Offered Rate (LIBOR) [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

2.60%

1.80%

London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

3.05%

2.25%

London Interbank Offered Rate (LIBOR) [Member] | Secured Debt [Member] | Term Loan 1 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

3.00%

Bank Bill Swap Bid Rate [Member] | Revolving Facility, June 2017 [Member] | Revolving Credit Facility [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

2.00%

Line of credit facility, interest rate at period end

3.90%

3.90%

3.90%

Bank Bill Swap Bid Rate [Member] | Medium-term Notes [Member] | Term Loan Due 2019 [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

2.00%

Debt instrument, interest rate at period end

3.99%

3.99%

3.99%

Sterling Base Rate [Member] | Invoice Discounting Arrangement [Member] | Secured Debt [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Debt instrument, basis spread on variable rate

2.00%

Special Dividends [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares

$ 1

Troy, Ohio [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Long-term debt, percentage bearing fixed interest, percentage rate

5.00%

5.00%

5.00%

Ocala, Florida [Member]

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]

Long-term debt, percentage bearing fixed interest, percentage rate

8.00%

8.00%

8.00%

[1]

In November 2012, Garant G.P. (“Garant”) entered into a CAD 15,000 ($11,498 as of September 30, 2018) revolving credit facility. The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum (3.70% LIBOR USD and 3.24% Bankers Acceptance Rate CDN as of September 30, 2018). The revolving facility matures in October 2019. Garant is required to maintain a certain minimum equity. As of September 30, 2018, there were no borrowings under the revolving credit facility with CAD 15,000 ($11,498 as of September 30, 2018) available for borrowin

[2]

Two Griffon subsidiaries have capital leases outstanding for real estate located in Troy, Ohio and Ocala, Florida. The leases mature in 2021 and 2022, respectively, and bear interest at fixed rates of approximately 5.0% and 8.0%, respectively. The Troy, Ohio lease is secured by a mortgage on the real estate and is guaranteed by Griffon. The Ocala, Florida lease contains two five-year renewal options.

[3]

On October 2, 2017, in an unregistered offering through a private placement under Rule 144A, Griffon completed the add-on offering of $275,000 principal amount of its 5.25% senior notes due 2022, at 101.0% of par, to Griffon's previously issued $125,000 principal amount of its 5.25% senior notes due 2022, at 98.76% of par, completed on May 18, 2016 and $600,000 5.25% senior notes due in 2022, at par, which was completed on February 27, 2014 (collectively the “Senior Notes”). As of September 30, 2018, outstanding Senior Notes due totaled $1,000,000; interest is payable semi-annually on March 1 and September 1. The net proceeds of the $275,000 add-on offering were used to acquire ClosetMaid with the remaining proceeds used to pay down outstanding loan borrowings under Griffon's Revolving Credit Facility (the "Credit Agreement"). The net proceeds of the previously issued $125,000 add-on offering were used to pay down outstanding revolving loan borrowings under the Credit Agreement.Proceeds from the $600,000 5.25% senior notes due in 2022 were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a call and tender offer premium of $31,530 and to make interest payments of $16,716, with the balance used to pay a portion of the related transaction fees and expenses. In connection with the issuance of the Senior Notes, all obligations under the $550,000 of 7.125% senior notes due in 2018 were discharged. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On February 5, 2018, July 20, 2016 and June 18, 2014, Griffon exchanged all of the $275,000, $125,000 and $600,000 Senior Notes, respectively, for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer. The fair value of the Senior Notes approximated $990,000 on September 30, 2018 based upon quoted market prices (level 1 inputs). In connection with the issuance and exchange of the $275,000 senior notes, Griffon capitalized $8,472 of underwriting fees and other expenses; in addition to $13,329 capitalized under the previously issued $725,000 Senior Notes. All capitalized fees for the Senior Notes will amortize over the term of the notes and, at September 30, 2018, $14,830 remained to be amortized.(b)On March 22, 2016, Griffon amended its Credit Agreement to increase the credit facility from $250,000 to $350,000, extend its maturity from March 13, 2020 to March 22, 2021, and modify certain other provisions of the facility. On October 2, 2017 and on May 31, 2018, Griffon amended the Credit Agreement in connection with the ClosetMaid and the CornellCookson acquisitions, respectively, to modify the net leverage covenant. The facility includes a letter of credit sub-facility with a limit of $50,000 and a multi-currency sub-facility of $100,000. The Credit Agreement provides for same day borrowings of base rate loans. Borrowings under the Credit Agreement may be repaid and re-borrowed at any time, subject to final maturity of the facility or the occurrence of an event of default under the Credit Agreement. Interest is payable on borrowings at either a LIBOR or base rate benchmark rate, in each case without a floor, plus an applicable margin, which adjusts based on financial performance. Current margins are 1.75% for base rate loans and 2.75% for LIBOR loans. The Credit Agreement has certain financial maintenance tests including a maximum total leverage ratio, a maximum senior secured leverage ratio and a minimum interest coverage ratio, as well as customary affirmative and negative covenants and events of default. The negative covenants place limits on Griffon's ability to, among other things, incur indebtedness, incur liens, and make restricted payments and investments. Borrowings under the Credit Agreement are guaranteed by Griffon’s material domestic subsidiaries and are secured, on a first priority basis, by substantially all domestic assets of the Company and the guarantors, and a pledge of not greater than 65% of the equity interest in Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon’s material domestic subsidiaries securing a limited amount of the debt under the credit agreement relating to Griffon's Employee Stock Ownership Plan ("ESOP") ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (e) below). At September 30, 2018, under the Credit Agreement, there were $25,000 outstanding borrowings; outstanding standby letters of credit were $14,623; and $310,377 was available, subject to certain loan covenants, for borrowing at that date

[4]

On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000, if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858, or 1,954,993 shares of common stock issued from treasury.(d)

[5]

In September 2015 and March 2016, Griffon entered into mortgage loans in the amount of $32,280 and $8,000, respectively, and were due to mature in September 2025 and April 2018, respectively. The mortgage loans were secured and collateralized by four properties occupied by Griffon's subsidiaries and were guaranteed by Griffon. The loans had an interest at a rate of LIBOR plus 1.50%.

[6]

In August 2016, Griffon’s ESOP entered into an agreement that refinanced the existing ESOP loan into a new Term Loan in the amount of $35,092 (the "Agreement"). The Agreement also provided for a Line Note with $10,908 available to purchase shares of Griffon common stock in the open market. During 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized. On June 30, 2017, the Term Loan and Line Note were combined into a single Term Loan. The Term Loan bears interest at LIBOR plus 3.0%. The Term Loan requires quarterly principal payments of $569 with a balloon payment due at maturity on March 22, 2020. As a result of the special cash dividend of $1.00 per share, paid on April 16, 2018, the outstanding balance of the Term Loan was reduced by $5,705. As of September 30, 2018, $34,508, net of issuance costs, was outstanding under the Term Loan. The Term Loan is secured by shares purchased with the proceeds of the loan and with a lien on a specific amount of Griffon assets (which lien ranks pari passu with the lien granted on such assets under the Credit Agreement) and is guaranteed by Griffon.

[7]

n July 2016, Griffon Australia Holdings Pty Ltd and its Australian subsidiaries ("Griffon Australia") entered into an AUD 30,000 term loan and an AUD 10,000 revolver. The term loan refinanced two existing term loans and the revolver replaced two existing lines. In December 2016, the amount available under the revolver was increased from AUD 10,000 to AUD 20,000 and, in March 2017 the term loan commitment was increased by AUD 5,000. In September 2017, the term commitment was increased by AUD 15,000. The term loan requires quarterly principal payments of AUD 1,250 plus interest with a balloon payment of AUD 37,125 due upon maturity in October 2019, and accrues interest at Bank Bill Swap Bid Rate “BBSY” plus 2.00% per annum (3.99% at September 30, 2018). As of September 30, 2018, the term had an outstanding balance of AUD 40,875 ($29,546 as of September 30, 2018). The revolving facility matures in March 2019, but is renewable upon mutual agreement with the lender, and accrues interest at BBSY plus 2.0% per annum (3.90% at September 30, 2018). At September 30, 2018, the revolver had an outstanding balance of AUD 11,000 ($7,951 at September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Griffon Australia and its subsidiaries. Griffon guarantees the term loan. Griffon Australia is required to maintain a certain minimum equity level and is subject to a maximum leverage ratio and a minimum fixed charges cover ratio.A UK subsidiary of Griffon maintained an invoice discounting arrangement secured by trade receivables. Interest was variable at 2.0% over the Sterling base rate. This facility was canceled in July 2018. In July 2018, the AMES Companies UK Ltd and its subsidiaries ("Ames UK") entered into a GBP 14,000 term loan, GBP 4,000 mortgage loan and GBP 5,000 revolver. The term loan and mortgage loan require quarterly principal payments of GBP 350 and GBP 83 plus interest, respectively, and have balloon payments due upon maturity, July 2023, of GBP 7,000 and GBP 2,333, respectively. The Term Loan and Mortgage Loans accrue interest at the GBP LIBOR Rate plus 2.25% and 1.8%, respectively (3.05% and 2.60% at September 30, 2018, respectively). The revolving facility matures in July 2019, but is renewable upon mutual agreement with the lender, and accrues interest at the Bank of England Base Rate plus 1.5% (2.25% as of September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Ames UK and its subsidiaries. Ames UK is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. The invoice discounting arrangement was canceled and replaced by the above loan facilities. As of September 30, 2018, outstanding borrowings on these facilities totaled $23,987.(h)

NOTES PAYABLE, CAPITALIZED LE_5

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt - USD ($)		12 Months Ended
		Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2016	Dec. 18, 2017
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		$ 60,349,000		$ 47,002,000		$ 42,622,000
Amortization of Debt Discount (Premium)		270,000		1,518,000		4,449,000
Amortization of Debt Issuance Costs		4,949,000		2,993,000		2,872,000
Interest Expense, Debt		65,568,000		51,513,000		49,943,000
Capitalized interest		(549,000)		$ (795,000)		(1,202,000)
Effective Interest Rate				5.55%
Outstanding Balance		1,134,692,000		$ 992,401,000
less: Current portion		(13,011,000)		(11,078,000)
Long-term debt		1,121,681,000		981,323,000
Original Issuer Discount		1,220,000		1,177,000
less: Current portion		0		0
Capitalized Fees & Expenses, Current		0		0
Long-term debt		(1,220,000)		(1,177,000)
Capitalized Fees & Expenses, Noncurrent		(14,830,000)		(12,066,000)
Balance Sheet		1,121,082,000		979,158,000
less: Current portion		(13,011,000)		(11,078,000)
Long-term debt		1,108,071,000		968,080,000
Capitalized fees & expenses		(14,830,000)		(12,066,000)
Senior note due 2022 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		52,500,000	[1]	38,063,000	[1]	33,906,000
Amortization of Debt Discount (Premium)		270,000	[1]	270,000	[1]	103
Amortization of Debt Issuance Costs		3,803,000	[1]	1,857,000	[1]	1,481,000
Interest Expense, Debt		$ 56,573,000	[1]	40,190,000	[1]	$ 35,490,000
Effective Interest Rate		5.66%	[1]			5.48%
Outstanding Balance	[1]	$ 1,000,000,000
Original Issuer Discount		1,220,000
Balance Sheet		988,252,000
Capitalized fees & expenses		$ (12,968,000)	[1]				$ (8,472,000)
Coupon Interest Rate	[1]	5.25%
Revolving Credit Facility [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities				4,951,000
Amortization of Debt Discount (Premium)				0
Amortization of Debt Issuance Costs				567,000
Interest Expense, Debt				5,518,000
Senior notes due 2018 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Outstanding Balance	[1]			725,000,000
Original Issuer Discount	[1]			1,177,000
Balance Sheet	[1]			714,603,000
Capitalized fees & expenses	[1]			$ (9,220,000)
Coupon Interest Rate	[1]			5.25%
Revolver due 2019 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Outstanding Balance		$ 25,000,000	[2]	$ 144,216,000	[1]
Original Issuer Discount		0	[2]	0	[1]
Balance Sheet		23,587,000	[2]	142,265,000	[1]
Capitalized fees & expenses		(1,413,000)	[2]	(1,951,000)	[1]
Convert. debt due 2017 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[2]	0		1,167,000		$ 4,000,000
Amortization of Debt Discount (Premium)	[2]	0		1,248,000		4,346,000
Amortization of Debt Issuance Costs	[2]	0		148,000		443,000
Interest Expense, Debt	[2]	0		$ 2,563,000		$ 8,789,000
Effective Interest Rate	[2]			8.90%		9.00%
Real estate mortgages [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[3]	349,000		$ 582,000		$ 439,000
Amortization of Debt Discount (Premium)	[3]	0		0		0
Amortization of Debt Issuance Costs	[3]	320,000		58,000		62,000
Interest Expense, Debt	[3]	$ 669,000		$ 640,000		$ 501,000
Effective Interest Rate	[3]	3.30%		2.60%		2.20%
Outstanding Balance	[3]			$ 23,642,000
Original Issuer Discount	[3]			0
Balance Sheet	[3]			23,322,000
Capitalized fees & expenses	[3]			(320,000)
ESOP Loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[4]	$ 1,802,000		1,557,000		$ 1,090,000
Amortization of Debt Discount (Premium)	[4]	0		0		0
Amortization of Debt Issuance Costs	[4]	124,000		133,000		236,000
Interest Expense, Debt	[4]	$ 1,926,000		$ 1,690,000		$ 1,326,000
Effective Interest Rate	[4]	6.30%		4.20%		3.10%
Outstanding Balance		$ 34,694,000	[5]	$ 42,675,000	[4]
Original Issuer Discount		0	[5]	0	[4]
Balance Sheet		34,508,000		42,365,000	[4]
Capitalized fees & expenses		(186,000)	[5]	(310,000)	[4]
Capital lease - real estate [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[5]	581,000		296,000		$ 353,000
Amortization of Debt Discount (Premium)	[5]	0		0		0
Amortization of Debt Issuance Costs	[5]	25,000		25,000		25,000
Interest Expense, Debt	[5]	606,000		$ 321,000		$ 378,000
Effective Interest Rate	[5]			5.50%		5.50%
Outstanding Balance		7,503,000	[6]	$ 5,312,000	[5]
Original Issuer Discount		0	[6]	0	[5]
Balance Sheet		7,423,000		5,207,000	[5]
Capitalized fees & expenses		$ (80,000)	[6]	$ (105,000)	[5]
Coupon Interest Rate		5.00%	[6]	5.00%	[5]
Non U.S. lines of credit [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[7]	$ 34,000		$ 76,000		$ 553,000
Amortization of Debt Discount (Premium)	[7]	0		0		0
Amortization of Debt Issuance Costs	[7]	15,000		128,000		91,000
Interest Expense, Debt	[7]	49,000		204,000		644,000
Outstanding Balance	[6]	7,951,000		9,402,000
Original Issuer Discount	[6]
Balance Sheet		7,935,000		9,371,000	[6]
Capitalized fees & expenses	[6]	(16,000)		(31,000)
Non U.S. term loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	[7]	1,420,000		860,000		659,000
Amortization of Debt Discount (Premium)	[7]	0		0		0
Amortization of Debt Issuance Costs	[7]	90,000		67,000		13,000
Interest Expense, Debt	[7]	1,510,000		927,000		672,000
Outstanding Balance		53,533,000	[7]	35,943,000	[6]
Original Issuer Discount		0	[7]	0	[6]
Balance Sheet		53,385,000		35,835,000	[6]
Capitalized fees & expenses		(148,000)	[7]	(108,000)	[6]
Other long term debt [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Long-Term Debt [Line Items]
Interest Paid, Including Capitalized Interest, Operating and Investing Activities		494,000		245,000		260,000
Amortization of Debt Discount (Premium)
Amortization of Debt Issuance Costs		7,000		10,000		9,000
Interest Expense, Debt		501,000		255,000		$ 269,000
Outstanding Balance	[7]	6,011,000		6,211,000
Original Issuer Discount	[7]	0		0
Balance Sheet		5,992,000		6,190,000	[7]
Capitalized fees & expenses	[7]	$ (19,000)		$ (21,000)
[1]	On October 2, 2017, in an unregistered offering through a private placement under Rule 144A, Griffon completed the add-on offering of $275,000 principal amount of its 5.25% senior notes due 2022, at 101.0% of par, to Griffon's previously issued $125,000 principal amount of its 5.25% senior notes due 2022, at 98.76% of par, completed on May 18, 2016 and $600,000 5.25% senior notes due in 2022, at par, which was completed on February 27, 2014 (collectively the “Senior Notes”). As of September 30, 2018, outstanding Senior Notes due totaled $1,000,000; interest is payable semi-annually on March 1 and September 1. The net proceeds of the $275,000 add-on offering were used to acquire ClosetMaid with the remaining proceeds used to pay down outstanding loan borrowings under Griffon's Revolving Credit Facility (the "Credit Agreement"). The net proceeds of the previously issued $125,000 add-on offering were used to pay down outstanding revolving loan borrowings under the Credit Agreement.Proceeds from the $600,000 5.25% senior notes due in 2022 were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a call and tender offer premium of $31,530 and to make interest payments of $16,716, with the balance used to pay a portion of the related transaction fees and expenses. In connection with the issuance of the Senior Notes, all obligations under the $550,000 of 7.125% senior notes due in 2018 were discharged. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On February 5, 2018, July 20, 2016 and June 18, 2014, Griffon exchanged all of the $275,000, $125,000 and $600,000 Senior Notes, respectively, for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer. The fair value of the Senior Notes approximated $990,000 on September 30, 2018 based upon quoted market prices (level 1 inputs). In connection with the issuance and exchange of the $275,000 senior notes, Griffon capitalized $8,472 of underwriting fees and other expenses; in addition to $13,329 capitalized under the previously issued $725,000 Senior Notes. All capitalized fees for the Senior Notes will amortize over the term of the notes and, at September 30, 2018, $14,830 remained to be amortized.(b)On March 22, 2016, Griffon amended its Credit Agreement to increase the credit facility from $250,000 to $350,000, extend its maturity from March 13, 2020 to March 22, 2021, and modify certain other provisions of the facility. On October 2, 2017 and on May 31, 2018, Griffon amended the Credit Agreement in connection with the ClosetMaid and the CornellCookson acquisitions, respectively, to modify the net leverage covenant. The facility includes a letter of credit sub-facility with a limit of $50,000 and a multi-currency sub-facility of $100,000. The Credit Agreement provides for same day borrowings of base rate loans. Borrowings under the Credit Agreement may be repaid and re-borrowed at any time, subject to final maturity of the facility or the occurrence of an event of default under the Credit Agreement. Interest is payable on borrowings at either a LIBOR or base rate benchmark rate, in each case without a floor, plus an applicable margin, which adjusts based on financial performance. Current margins are 1.75% for base rate loans and 2.75% for LIBOR loans. The Credit Agreement has certain financial maintenance tests including a maximum total leverage ratio, a maximum senior secured leverage ratio and a minimum interest coverage ratio, as well as customary affirmative and negative covenants and events of default. The negative covenants place limits on Griffon's ability to, among other things, incur indebtedness, incur liens, and make restricted payments and investments. Borrowings under the Credit Agreement are guaranteed by Griffon’s material domestic subsidiaries and are secured, on a first priority basis, by substantially all domestic assets of the Company and the guarantors, and a pledge of not greater than 65% of the equity interest in Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon’s material domestic subsidiaries securing a limited amount of the debt under the credit agreement relating to Griffon's Employee Stock Ownership Plan ("ESOP") ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (e) below). At September 30, 2018, under the Credit Agreement, there were $25,000 outstanding borrowings; outstanding standby letters of credit were $14,623; and $310,377 was available, subject to certain loan covenants, for borrowing at that date
[2]	On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000, if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858, or 1,954,993 shares of common stock issued from treasury.(d)
[3]	In September 2015 and March 2016, Griffon entered into mortgage loans in the amount of $32,280 and $8,000, respectively, and were due to mature in September 2025 and April 2018, respectively. The mortgage loans were secured and collateralized by four properties occupied by Griffon's subsidiaries and were guaranteed by Griffon. The loans had an interest at a rate of LIBOR plus 1.50%.
[4]	In August 2016, Griffon’s ESOP entered into an agreement that refinanced the existing ESOP loan into a new Term Loan in the amount of $35,092 (the "Agreement"). The Agreement also provided for a Line Note with $10,908 available to purchase shares of Griffon common stock in the open market. During 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized. On June 30, 2017, the Term Loan and Line Note were combined into a single Term Loan. The Term Loan bears interest at LIBOR plus 3.0%. The Term Loan requires quarterly principal payments of $569 with a balloon payment due at maturity on March 22, 2020. As a result of the special cash dividend of $1.00 per share, paid on April 16, 2018, the outstanding balance of the Term Loan was reduced by $5,705. As of September 30, 2018, $34,508, net of issuance costs, was outstanding under the Term Loan. The Term Loan is secured by shares purchased with the proceeds of the loan and with a lien on a specific amount of Griffon assets (which lien ranks pari passu with the lien granted on such assets under the Credit Agreement) and is guaranteed by Griffon.
[5]	Two Griffon subsidiaries have capital leases outstanding for real estate located in Troy, Ohio and Ocala, Florida. The leases mature in 2021 and 2022, respectively, and bear interest at fixed rates of approximately 5.0% and 8.0%, respectively. The Troy, Ohio lease is secured by a mortgage on the real estate and is guaranteed by Griffon. The Ocala, Florida lease contains two five-year renewal options.
[6]	In November 2012, Garant G.P. (“Garant”) entered into a CAD 15,000 ($11,498 as of September 30, 2018) revolving credit facility. The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum (3.70% LIBOR USD and 3.24% Bankers Acceptance Rate CDN as of September 30, 2018). The revolving facility matures in October 2019. Garant is required to maintain a certain minimum equity. As of September 30, 2018, there were no borrowings under the revolving credit facility with CAD 15,000 ($11,498 as of September 30, 2018) available for borrowin
[7]	n July 2016, Griffon Australia Holdings Pty Ltd and its Australian subsidiaries ("Griffon Australia") entered into an AUD 30,000 term loan and an AUD 10,000 revolver. The term loan refinanced two existing term loans and the revolver replaced two existing lines. In December 2016, the amount available under the revolver was increased from AUD 10,000 to AUD 20,000 and, in March 2017 the term loan commitment was increased by AUD 5,000. In September 2017, the term commitment was increased by AUD 15,000. The term loan requires quarterly principal payments of AUD 1,250 plus interest with a balloon payment of AUD 37,125 due upon maturity in October 2019, and accrues interest at Bank Bill Swap Bid Rate “BBSY” plus 2.00% per annum (3.99% at September 30, 2018). As of September 30, 2018, the term had an outstanding balance of AUD 40,875 ($29,546 as of September 30, 2018). The revolving facility matures in March 2019, but is renewable upon mutual agreement with the lender, and accrues interest at BBSY plus 2.0% per annum (3.90% at September 30, 2018). At September 30, 2018, the revolver had an outstanding balance of AUD 11,000 ($7,951 at September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Griffon Australia and its subsidiaries. Griffon guarantees the term loan. Griffon Australia is required to maintain a certain minimum equity level and is subject to a maximum leverage ratio and a minimum fixed charges cover ratio.A UK subsidiary of Griffon maintained an invoice discounting arrangement secured by trade receivables. Interest was variable at 2.0% over the Sterling base rate. This facility was canceled in July 2018. In July 2018, the AMES Companies UK Ltd and its subsidiaries ("Ames UK") entered into a GBP 14,000 term loan, GBP 4,000 mortgage loan and GBP 5,000 revolver. The term loan and mortgage loan require quarterly principal payments of GBP 350 and GBP 83 plus interest, respectively, and have balloon payments due upon maturity, July 2023, of GBP 7,000 and GBP 2,333, respectively. The Term Loan and Mortgage Loans accrue interest at the GBP LIBOR Rate plus 2.25% and 1.8%, respectively (3.05% and 2.60% at September 30, 2018, respectively). The revolving facility matures in July 2019, but is renewable upon mutual agreement with the lender, and accrues interest at the Bank of England Base Rate plus 1.5% (2.25% as of September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Ames UK and its subsidiaries. Ames UK is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. The invoice discounting arrangement was canceled and replaced by the above loan facilities. As of September 30, 2018, outstanding borrowings on these facilities totaled $23,987.(h)

NOTES PAYABLE, CAPITALIZED LE_6

NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred - USD ($)		12 Months Ended
		Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2016
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate				5.55%
Cash Interest		$ 60,349,000		$ 47,002,000		$ 42,622,000
Amort. Debt Discount		270,000		1,518,000		4,449,000
Amort. Deferred Cost & Other Fees		4,949,000		2,993,000		2,872,000
Total Interest Expense		$ 65,568,000		51,513,000		$ 49,943,000
Senior note due 2022 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate		5.66%	[1]			5.48%
Cash Interest		$ 52,500,000	[1]	38,063,000	[1]	$ 33,906,000
Amort. Debt Discount		270,000	[1]	270,000	[1]	103
Amort. Deferred Cost & Other Fees		3,803,000	[1]	1,857,000	[1]	1,481,000
Total Interest Expense		56,573,000	[1]	$ 40,190,000	[1]	35,490,000
Revolver due 2018 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	[1]	3,718,000				2,564,000
Amort. Debt Discount	[1]	0				0
Amort. Deferred Cost & Other Fees	[1]	565,000				512,000
Total Interest Expense	[1]	4,283,000				$ 3,076,000
Convert. debt due 2017 [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	[2]			8.90%		9.00%
Cash Interest	[2]	0		$ 1,167,000		$ 4,000,000
Amort. Debt Discount	[2]	0		1,248,000		4,346,000
Amort. Deferred Cost & Other Fees	[2]	0		148,000		443,000
Total Interest Expense	[2]	$ 0		$ 2,563,000		$ 8,789,000
Real estate mortgages [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	[3]	3.30%		2.60%		2.20%
Cash Interest	[3]	$ 349,000		$ 582,000		$ 439,000
Amort. Debt Discount	[3]	0		0		0
Amort. Deferred Cost & Other Fees	[3]	320,000		58,000		62,000
Total Interest Expense	[3]	$ 669,000		$ 640,000		$ 501,000
ESOP Loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	[4]	6.30%		4.20%		3.10%
Cash Interest	[4]	$ 1,802,000		$ 1,557,000		$ 1,090,000
Amort. Debt Discount	[4]	0		0		0
Amort. Deferred Cost & Other Fees	[4]	124,000		133,000		236,000
Total Interest Expense	[4]	1,926,000		$ 1,690,000		$ 1,326,000
Capital lease - real estate [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	[5]			5.50%		5.50%
Cash Interest	[5]	581,000		$ 296,000		$ 353,000
Amort. Debt Discount	[5]	0		0		0
Amort. Deferred Cost & Other Fees	[5]	25,000		25,000		25,000
Total Interest Expense	[5]	606,000		321,000		378,000
Non U.S. lines of credit [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	[6]	34,000		76,000		553,000
Amort. Debt Discount	[6]	0		0		0
Amort. Deferred Cost & Other Fees	[6]	15,000		128,000		91,000
Total Interest Expense	[6]	49,000		204,000		644,000
Non U.S. term loans [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	[6]	1,420,000		860,000		659,000
Amort. Debt Discount	[6]	0		0		0
Amort. Deferred Cost & Other Fees	[6]	90,000		67,000		13,000
Total Interest Expense	[6]	1,510,000		927,000		672,000
Other long term debt [Member]
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest		494,000		245,000		260,000
Amort. Debt Discount
Amort. Deferred Cost & Other Fees		7,000		10,000		9,000
Total Interest Expense		$ 501,000		$ 255,000		$ 269,000
[1]	On October 2, 2017, in an unregistered offering through a private placement under Rule 144A, Griffon completed the add-on offering of $275,000 principal amount of its 5.25% senior notes due 2022, at 101.0% of par, to Griffon's previously issued $125,000 principal amount of its 5.25% senior notes due 2022, at 98.76% of par, completed on May 18, 2016 and $600,000 5.25% senior notes due in 2022, at par, which was completed on February 27, 2014 (collectively the “Senior Notes”). As of September 30, 2018, outstanding Senior Notes due totaled $1,000,000; interest is payable semi-annually on March 1 and September 1. The net proceeds of the $275,000 add-on offering were used to acquire ClosetMaid with the remaining proceeds used to pay down outstanding loan borrowings under Griffon's Revolving Credit Facility (the "Credit Agreement"). The net proceeds of the previously issued $125,000 add-on offering were used to pay down outstanding revolving loan borrowings under the Credit Agreement.Proceeds from the $600,000 5.25% senior notes due in 2022 were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a call and tender offer premium of $31,530 and to make interest payments of $16,716, with the balance used to pay a portion of the related transaction fees and expenses. In connection with the issuance of the Senior Notes, all obligations under the $550,000 of 7.125% senior notes due in 2018 were discharged. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On February 5, 2018, July 20, 2016 and June 18, 2014, Griffon exchanged all of the $275,000, $125,000 and $600,000 Senior Notes, respectively, for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer. The fair value of the Senior Notes approximated $990,000 on September 30, 2018 based upon quoted market prices (level 1 inputs). In connection with the issuance and exchange of the $275,000 senior notes, Griffon capitalized $8,472 of underwriting fees and other expenses; in addition to $13,329 capitalized under the previously issued $725,000 Senior Notes. All capitalized fees for the Senior Notes will amortize over the term of the notes and, at September 30, 2018, $14,830 remained to be amortized.(b)On March 22, 2016, Griffon amended its Credit Agreement to increase the credit facility from $250,000 to $350,000, extend its maturity from March 13, 2020 to March 22, 2021, and modify certain other provisions of the facility. On October 2, 2017 and on May 31, 2018, Griffon amended the Credit Agreement in connection with the ClosetMaid and the CornellCookson acquisitions, respectively, to modify the net leverage covenant. The facility includes a letter of credit sub-facility with a limit of $50,000 and a multi-currency sub-facility of $100,000. The Credit Agreement provides for same day borrowings of base rate loans. Borrowings under the Credit Agreement may be repaid and re-borrowed at any time, subject to final maturity of the facility or the occurrence of an event of default under the Credit Agreement. Interest is payable on borrowings at either a LIBOR or base rate benchmark rate, in each case without a floor, plus an applicable margin, which adjusts based on financial performance. Current margins are 1.75% for base rate loans and 2.75% for LIBOR loans. The Credit Agreement has certain financial maintenance tests including a maximum total leverage ratio, a maximum senior secured leverage ratio and a minimum interest coverage ratio, as well as customary affirmative and negative covenants and events of default. The negative covenants place limits on Griffon's ability to, among other things, incur indebtedness, incur liens, and make restricted payments and investments. Borrowings under the Credit Agreement are guaranteed by Griffon’s material domestic subsidiaries and are secured, on a first priority basis, by substantially all domestic assets of the Company and the guarantors, and a pledge of not greater than 65% of the equity interest in Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon’s material domestic subsidiaries securing a limited amount of the debt under the credit agreement relating to Griffon's Employee Stock Ownership Plan ("ESOP") ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (e) below). At September 30, 2018, under the Credit Agreement, there were $25,000 outstanding borrowings; outstanding standby letters of credit were $14,623; and $310,377 was available, subject to certain loan covenants, for borrowing at that date
[2]	On December 21, 2009, Griffon issued $100,000 principal of 4% convertible subordinated notes due 2017 (the “2017 Notes”). On July 14, 2016, Griffon announced that it would settle, upon conversion, up to $125,000 of the conversion value of the 2017 Notes in cash, with amounts in excess of $125,000, if any, to be settled in shares of Griffon common stock. On January 17, 2017, Griffon settled the convertible debt for $173,855 with $125,000 in cash, utilizing borrowings under the Credit Agreement, and $48,858, or 1,954,993 shares of common stock issued from treasury.(d)
[3]	In September 2015 and March 2016, Griffon entered into mortgage loans in the amount of $32,280 and $8,000, respectively, and were due to mature in September 2025 and April 2018, respectively. The mortgage loans were secured and collateralized by four properties occupied by Griffon's subsidiaries and were guaranteed by Griffon. The loans had an interest at a rate of LIBOR plus 1.50%.
[4]	In August 2016, Griffon’s ESOP entered into an agreement that refinanced the existing ESOP loan into a new Term Loan in the amount of $35,092 (the "Agreement"). The Agreement also provided for a Line Note with $10,908 available to purchase shares of Griffon common stock in the open market. During 2017, Griffon's ESOP purchased 621,875 shares of common stock for a total of $10,908 or $17.54 per share, under a borrowing line that has now been fully utilized. On June 30, 2017, the Term Loan and Line Note were combined into a single Term Loan. The Term Loan bears interest at LIBOR plus 3.0%. The Term Loan requires quarterly principal payments of $569 with a balloon payment due at maturity on March 22, 2020. As a result of the special cash dividend of $1.00 per share, paid on April 16, 2018, the outstanding balance of the Term Loan was reduced by $5,705. As of September 30, 2018, $34,508, net of issuance costs, was outstanding under the Term Loan. The Term Loan is secured by shares purchased with the proceeds of the loan and with a lien on a specific amount of Griffon assets (which lien ranks pari passu with the lien granted on such assets under the Credit Agreement) and is guaranteed by Griffon.
[5]	Two Griffon subsidiaries have capital leases outstanding for real estate located in Troy, Ohio and Ocala, Florida. The leases mature in 2021 and 2022, respectively, and bear interest at fixed rates of approximately 5.0% and 8.0%, respectively. The Troy, Ohio lease is secured by a mortgage on the real estate and is guaranteed by Griffon. The Ocala, Florida lease contains two five-year renewal options.
[6]	n July 2016, Griffon Australia Holdings Pty Ltd and its Australian subsidiaries ("Griffon Australia") entered into an AUD 30,000 term loan and an AUD 10,000 revolver. The term loan refinanced two existing term loans and the revolver replaced two existing lines. In December 2016, the amount available under the revolver was increased from AUD 10,000 to AUD 20,000 and, in March 2017 the term loan commitment was increased by AUD 5,000. In September 2017, the term commitment was increased by AUD 15,000. The term loan requires quarterly principal payments of AUD 1,250 plus interest with a balloon payment of AUD 37,125 due upon maturity in October 2019, and accrues interest at Bank Bill Swap Bid Rate “BBSY” plus 2.00% per annum (3.99% at September 30, 2018). As of September 30, 2018, the term had an outstanding balance of AUD 40,875 ($29,546 as of September 30, 2018). The revolving facility matures in March 2019, but is renewable upon mutual agreement with the lender, and accrues interest at BBSY plus 2.0% per annum (3.90% at September 30, 2018). At September 30, 2018, the revolver had an outstanding balance of AUD 11,000 ($7,951 at September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Griffon Australia and its subsidiaries. Griffon guarantees the term loan. Griffon Australia is required to maintain a certain minimum equity level and is subject to a maximum leverage ratio and a minimum fixed charges cover ratio.A UK subsidiary of Griffon maintained an invoice discounting arrangement secured by trade receivables. Interest was variable at 2.0% over the Sterling base rate. This facility was canceled in July 2018. In July 2018, the AMES Companies UK Ltd and its subsidiaries ("Ames UK") entered into a GBP 14,000 term loan, GBP 4,000 mortgage loan and GBP 5,000 revolver. The term loan and mortgage loan require quarterly principal payments of GBP 350 and GBP 83 plus interest, respectively, and have balloon payments due upon maturity, July 2023, of GBP 7,000 and GBP 2,333, respectively. The Term Loan and Mortgage Loans accrue interest at the GBP LIBOR Rate plus 2.25% and 1.8%, respectively (3.05% and 2.60% at September 30, 2018, respectively). The revolving facility matures in July 2019, but is renewable upon mutual agreement with the lender, and accrues interest at the Bank of England Base Rate plus 1.5% (2.25% as of September 30, 2018). The revolver and the term loan are both secured by substantially all of the assets of Ames UK and its subsidiaries. Ames UK is subject to a maximum leverage ratio and a minimum fixed charges cover ratio. The invoice discounting arrangement was canceled and replaced by the above loan facilities. As of September 30, 2018, outstanding borrowings on these facilities totaled $23,987.(h)

EMPLOYEE BENEFIT PLANS (Details

EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Jan. 01, 2018
EMPLOYEE BENEFIT PLANS (Details) [Line Items]
Defined contribution plan, employer discretionary contribution amount	$ 8,328	$ 8,714	$ 8,301
Postemployment benefits liability	$ 1,699	2,014
Change in discount rate	10.00%
Tax benefit for amortization of pension cost	$ 342	1,170	831
Defined benefit plan, actuarial gain (loss)	887
Service cost	$ 14
Adjusted funding target attainment percent				95.80%
Adjusted funding target attainment percent, threshold				80.00%
Defined benefit plan, target plan asset allocations	100.00%
Defined benefit plans, estimated future employer contributions in next fiscal year	$ 1,100
Completion period of service	1 year
Maximum compensation of proportion	$ 275
Employee stock ownership plan (ESOP), compensation expense	9,532	5,643	$ 3,689
Employee stock ownership plan (ESOP), deferred shares, fair value	47,916	69,394
Other Postretirement Benefits Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(60)	(107)
Pension and other postretirement benefit expense	45	41
Supplemental Employee Retirement Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(3,396)	(12,601)
Company contributions	3,001	4,057
Defined benefit plan, actuarial gain (loss)	14,452	(195)
Defined benefit plan, expected future benefit payments, next twelve months	1,906
Pension Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) [Line Items]
Accumulated other comprehensive income (loss), pension and other postretirement benefit plans, net of tax	(12,985)	(15,539)
Company contributions	2,449	3,747
Defined benefit plan, actuarial gain (loss)	7,562	$ 9,318
Defined benefit plan, expected future benefit payments, next twelve months	10,767
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	$ 3,114

EMPLOYEE BENEFIT PLANS (Detai_2

EMPLOYEE BENEFIT PLANS (Details) - Schedule of net periodic costs - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Net periodic (benefits) costs:
Service cost	$ 14
Pension Plan [Member]
Net periodic (benefits) costs:
Interest cost	5,084	$ 4,892	$ 5,465
Expected return on plan assets	(10,736)	(10,943)	(10,934)
Amortization of:
Prior service costs	0	1	1
Actuarial loss	755	1,980	1,131
Total net periodic (benefits) costs	(4,897)	(4,070)	(4,337)
Supplemental Employee Retirement Plan [Member]
Net periodic (benefits) costs:
Interest cost	544	715	1,243
Expected return on plan assets	0	0	0
Amortization of:
Prior service costs	14	15	19
Actuarial loss	628	1,347	1,224
Total net periodic (benefits) costs	$ 1,186	$ 2,077	$ 2,486

EMPLOYEE BENEFIT PLANS (Detai_3

EMPLOYEE BENEFIT PLANS (Details) - Weighted-average assumptions used in determining the net periodic benefit costs	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Pension Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Weighted-average assumptions used in determining the net periodic benefit costs [Line Items]
Discount rate	4.10%	3.64%	3.42%
Expected return on assets	7.00%	7.25%	7.50%
Supplemental Employee Retirement Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Weighted-average assumptions used in determining the net periodic benefit costs [Line Items]
Discount rate	3.99%	3.18%	2.86%
Expected return on assets	0.00%	0.00%	0.00%

EMPLOYEE BENEFIT PLANS (Detai_4

EMPLOYEE BENEFIT PLANS (Details) - Plan assets and benefit obligation of the defined benefit plans - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Change in benefit obligation:
Actuarial (gain) loss	$ (887)
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	150,822
Fair value of plan assets at end of fiscal year	150,634	$ 150,822
Pension Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of fiscal year	174,337	189,156
Interest cost	5,084	4,892	$ 5,465
Benefits paid	(10,531)	(10,393)
Actuarial (gain) loss	(7,562)	(9,318)
Benefit obligation at end of fiscal year	161,328	174,337	189,156
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	150,822	144,316
Actual return on plan assets	7,940	13,152
Company contributions	2,449	3,747
Benefits paid	(10,531)	(10,393)
Fair value of plan assets at end of fiscal year	150,680	150,822	144,316
Projected benefit obligation in excess of plan assets	10,648	23,515
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	0	0
Other liabilities (long-term)	(10,648)	(23,515)
Total Liabilities	(10,648)	(23,515)
Net actuarial losses	19,088	24,608
Prior service cost	0	0
Deferred taxes	(6,103)	(9,069)
Total Accumulated other comprehensive loss, net of tax	12,985	15,539
Net amount recognized at September 30,	2,337	(7,976)
Accumulated benefit obligations	161,328	174,337
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	161,328	174,337
PBO	(10,648)	(23,515)
Fair value of plan assets	150,680	150,822
Supplemental Employee Retirement Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of fiscal year	32,627	35,774
Interest cost	544	715	1,243
Benefits paid	(3,001)	(4,057)
Actuarial (gain) loss	(14,452)	195
Benefit obligation at end of fiscal year	15,718	32,627	35,774
Change in plan assets:
Fair value of plan assets at beginning of fiscal year	0	0
Actual return on plan assets	0	0
Company contributions	3,001	4,057
Benefits paid	(3,001)	(4,057)
Fair value of plan assets at end of fiscal year	0	0	$ 0
Projected benefit obligation in excess of plan assets	15,718	32,627
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	(1,906)	(3,984)
Other liabilities (long-term)	(13,812)	(28,643)
Total Liabilities	(15,718)	(32,627)
Net actuarial losses	4,965	20,045
Prior service cost	28	42
Deferred taxes	(1,597)	(7,486)
Total Accumulated other comprehensive loss, net of tax	3,396	12,601
Net amount recognized at September 30,	(12,322)	(20,026)
Accumulated benefit obligations	15,718	32,627
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	15,718	32,627
PBO	(15,718)	(32,627)
Fair value of plan assets	$ 0	$ 0

EMPLOYEE BENEFIT PLANS (Detai_5

EMPLOYEE BENEFIT PLANS (Details) - Schedule of weighted average assumptions used in determining benefit obligations	Sep. 30, 2018	Sep. 30, 2017
Pension Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Schedule of weighted average assumptions used in determining benefit obligations [Line Items]
Weighted average discount rate	4.10%	3.64%
Supplemental Employee Retirement Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Schedule of weighted average assumptions used in determining benefit obligations [Line Items]
Weighted average discount rate	3.99%	3.18%

EMPLOYEE BENEFIT PLANS (Detai_6

EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans	Sep. 30, 2018	Sep. 30, 2017
EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans [Line Items]
Defined benefit plan, total actual weighted average plan asset allocations	100.00%	100.00%
Target Plan Asset Allocations	100.00%
Cash and equivalents [Member]
EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans [Line Items]
Defined benefit plan, total actual weighted average plan asset allocations	18.00%	18.00%
Target Plan Asset Allocations	0.00%
Equity securities [Member]
EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans [Line Items]
Defined benefit plan, total actual weighted average plan asset allocations	68.50%	58.00%
Target Plan Asset Allocations	63.00%
Fixed income [Member]
EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans [Line Items]
Defined benefit plan, total actual weighted average plan asset allocations	9.50%	19.30%
Target Plan Asset Allocations	37.00%
Other [Member]
EMPLOYEE BENEFIT PLANS (Details) - Actual and weighted-average assets allocation for qualified benefit plans [Line Items]
Defined benefit plan, total actual weighted average plan asset allocations	4.00%	4.70%
Target Plan Asset Allocations	0.00%

EMPLOYEE BENEFIT PLANS (Detai_7

EMPLOYEE BENEFIT PLANS (Details) - Estimated future benefit payments to retirees $ in Thousands	Sep. 30, 2018USD ($)
Pension Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Estimated future benefit payments to retirees [Line Items]
2,018	$ 10,767
2,019	10,892
2,020	10,979
2,021	10,960
2,022	10,950
2024 through 2028	53,652
Supplemental Employee Retirement Plan [Member]
EMPLOYEE BENEFIT PLANS (Details) - Estimated future benefit payments to retirees [Line Items]
2,018	1,906
2,019	1,822
2,020	1,734
2,021	1,642
2,022	1,545
2024 through 2028	$ 6,068

EMPLOYEE BENEFIT PLANS (Detai_8

EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 150,634	$ 150,822
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	82,520	82,099
Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	68,114	68,723
Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Cash and equivalents [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	27,209	27,156
Cash and equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	27,209	27,156
Cash and equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Cash and equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Debt instruments [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	14,269	14,520
Debt instruments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	14,269	14,520
Debt instruments [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Debt instruments [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Equity securities [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	41,042	40,423
Equity securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	41,042	40,423
Equity securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Equity securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Commingled funds [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	62,088	62,907
Commingled funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Commingled funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	62,088	62,907
Commingled funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Limited partnerships and hedge fund investments [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6,026	5,816
Limited partnerships and hedge fund investments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Limited partnerships and hedge fund investments [Member] | Significant Other Observable Inputs (Level 2) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6,026	5,816
Limited partnerships and hedge fund investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
EMPLOYEE BENEFIT PLANS (Details) - Pension and post-retirement plan assets by asset category [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 0	$ 0

EMPLOYEE BENEFIT PLANS (Detai_9

EMPLOYEE BENEFIT PLANS (Details) - ESOP Shares - shares	Sep. 30, 2018	Sep. 30, 2017
Retirement Benefits [Abstract]
Allocated shares	3,157,530	2,676,486
Unallocated shares	2,477,385	3,125,850
Employee Stock Ownership Plan (ESOP), Shares in ESOP	5,634,915	5,802,336

INCOME TAXES (Details) - Compon

INCOME TAXES (Details) - Components of Income before taxes and discontinued operations - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Domestic	$ 4,942	$ (1,339)	$ 23,163
Non-U.S.	28,868	18,037	9,050
Income (loss) before taxes from continuing operations	$ 33,810	$ 16,698	$ 32,213

INCOME TAXES (Details) - Provis

INCOME TAXES (Details) - Provision (benefit) for income taxes on income from continuing operations - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Current	$ 18,188	$ (3,426)	$ 6,388
Deferred	(17,633)	2,341	6,044
Total provision	555	(1,085)	12,432
U.S. Federal	(12,714)	(6,689)	4,358
State and local	5,175	3,307	3,287
Non-U.S.	$ 8,094	$ 2,297	$ 4,787

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
INCOME TAXES (Details) [Line Items]
U.S. Federal income tax provision (benefit) rate	24.50%	35.00%	35.00%
Provisional income tax (expense) benefit	$ 20,587
Share-based compensation, excess tax benefit, amount	2,193
Income Tax Benefits Reflected Reversal Of Previously Recorded Tax Liabilities	(421)	$ (122)	$ (2,172)
Valuation allowance increase (decrease)	8,946
Undistributed Earnings of Foreign Subsidiaries	64,204
Potential Tax Benefits Impact On Effective Tax Rate	1,248
Liability for Uncertainty in Income Taxes, Current	122	174
Deferred Tax Assets, Valuation Allowance	7,597	1,343
Domestic Tax Authority [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	6,089	1,264
Non U S Tax Purposes [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	7,319	7,941
State and Local Jurisdiction [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	124,442	114,837
Foreign Tax Authority [Member]
INCOME TAXES (Details) [Line Items]
Operating Loss Carryforwards	5,740	1,762
New Accounting Pronouncement, Early Adoption, Effect [Member]
INCOME TAXES (Details) [Line Items]
Share-based compensation, excess tax benefit, amount	$ 1,299	$ 4,440

INCOME TAXES (Details) - Schedu

INCOME TAXES (Details) - Schedule of effective income tax rate reconciliation	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
U.S. Federal income tax provision (benefit) rate	24.50%	35.00%	35.00%
State and local taxes, net of Federal benefit	10.20%	12.40%	6.60%
Non-U.S. taxes	3.60%	(12.40%)	(1.60%)
Non-U.S. taxes - foreign permanent items and taxes	0.00%	(11.40%)	0.00%
Change in domestic manufacturing deduction	(0.00%)	(5.80%)	(0.00%)
Change in tax contingency reserves	(0.60%)	0.70%	(6.30%)
Impact of federal rate change on deferred tax balances	(60.00%)	0.00%	0.00%
Repatriation of foreign earnings	61.60%	0.00%	0.00%
Change in valuation allowance	13.40%	(0.60%)	(0.60%)
Non-deductible/non-taxable items, net	(2.40%)	8.30%	2.60%
Research credits	(39.40%)	(3.60%)	8.80%
Share based compensation	(3.80%)	(26.60%)	(5.70%)
Other	(5.50%)	(2.50%)	(0.20%)
Effective tax provision (benefit) rate	1.60%	(6.50%)	38.60%

INCOME TAXES (Details) - Sche_2

INCOME TAXES (Details) - Schedule of deferred tax assets and liabilities - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Deferred tax assets:
Bad debt reserves	$ 1,404	$ 2,509
Inventory reserves	7,709	7,615
Deferred compensation (equity compensation and defined benefit plans)	11,437	27,430
Compensation benefits	5,434	6,111
Insurance reserve	1,782	2,985
Restructuring reserve	0	29
Warranty reserve	2,598	2,893
Net operating loss	10,593	37,383
Tax credits	6,379	1,866
Other reserves and accruals	5,433	7,658
Deferred Tax Assets, Gross	52,769	96,479
Valuation allowance	(8,520)	(17,466)
Total deferred tax assets	44,249	79,013
Deferred tax liabilities:
Deferred income	0	(1,862)
Goodwill and intangibles	(44,402)	(70,560)
Property, plant and equipment	(39,260)	(51,488)
Deferred gain on assets held for sale	0	(16,300)
Other	(1,086)	(1,016)
Total deferred tax liabilities	(84,748)	(141,226)
Net deferred liability	$ (40,499)	$ (62,213)

INCOME TAXES (Details) - Comp_2

INCOME TAXES (Details) - Components of net deferred tax asset (liability), by balance sheet account - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Income Tax Contingency [Line Items]
Net deferred liability	$ (40,499)	$ (62,213)
Other Assets [Member]
Income Tax Contingency [Line Items]
Net deferred liability	61	6
Assets Of Discontinued Operations Held For Sale [Member]
Income Tax Contingency [Line Items]
Net deferred liability	0	6,745
Other Liabilities [Member]
Income Tax Contingency [Line Items]
Net deferred liability	(42,689)	(58,505)
Liabilities Of Discontinued Operations Held For Sale [Member]
Income Tax Contingency [Line Items]
Net deferred liability	872	(12,584)
Liabilities Of Discontinued Operations Not Held For Sale [Member]
Income Tax Contingency [Line Items]
Net deferred liability	$ 1,257	$ 2,125

INCOME TAXES (Details) - Sche_3

INCOME TAXES (Details) - Schedule of unrecognized tax benefits - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance	$ 4,825	$ 4,709
Additions based on tax positions related to the current year	152	177
Additions based on tax positions related to prior years	26	69	$ (253)
Reductions based on tax positions related to prior years		(8)
Lapse of Statutes	(194)	(122)
Settlements	(37)
Balance	$ 4,519	$ 4,825	$ 4,709

STOCKHOLDERS' EQUITY AND EQUI_3

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details)

Apr. 16, 2018USD ($)$ / shares

Mar. 07, 2018USD ($)$ / shares

Jan. 17, 2017USD ($)shares

Jul. 14, 2016USD ($)

Jan. 29, 2016shares

Dec. 10, 2013$ / sharesshares

Sep. 30, 2017$ / sharesshares

Sep. 30, 2018USD ($)senior_executive$ / sharesshares

Sep. 30, 2017USD ($)$ / sharesshares

Sep. 30, 2016USD ($)$ / shares

Jan. 29, 2020shares

Nov. 14, 2018$ / shares

Jun. 19, 2018shares

Jan. 31, 2018shares

Oct. 02, 2017

Aug. 31, 2016USD ($)

May 18, 2016

Jul. 31, 2015USD ($)

Mar. 31, 2015USD ($)

Jun. 18, 2014USD ($)

Feb. 27, 2014

Aug. 31, 2011USD ($)

Dec. 21, 2009USD ($)

Dec. 31, 2008shares

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Options Outstanding & Exercisable Shares (in Shares)

350,000

Options Outstanding & Exercisable Weighted Average Exercise Price (in Dollars per Share) | $ / shares

$ 20

Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares

$ 0.28

$ 0.24

$ 0.20

Share-based payment award, description

Options granted under the Incentive Plan may be either “incentive stock options” or nonqualified stock options, generally expire ten years after the date of grant and are granted at an exercise price of not less than 100% of the fair market value at the date of grant.

Share-based payment award, expiration period

10 years

Maximum percentage of exercise price at grant date fair value

100.00%

Share-based payment award, number of shares authorized (in Shares)

4,345,662

Share-based payment award, options, vested in period, fair value | $

$ 11,216,000

$ 29,508,000

$ 23,965,000

Employee service share-based compensation, nonvested awards, compensation not yet recognized, share-based awards other than options | $

$ 22,869,000

Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition

2 years 3 months

Stock repurchased during period, shares (in Shares)

4,444,444

2,088,739

Stock repurchased during period, value | $

$ 41,110,000

Stock repurchased during period per share (in Dollars per share) | $ / shares

$ 11.25

$ 19.68

Stock repurchased during period, share price discount rate

9.20%

Stock repurchase program, authorized amount | $

$ 50,000,000

$ 50,000,000

$ 50,000,000

$ 50,000,000

Stock repurchase program, remaining authorized repurchase amount | $

$ 58,327,000

Shares paid for tax withholding for share based compensation (in Shares)

199,978

Shares paid for tax withholding for share based compensation, value | $

$ 4,495,000

Shares paid for tax withholding for share based compensation, value per share (in Dollars per share) | $ / shares

$ 22.48

Stock issued during period, shares, ESOP

621,875

Common Stock, Number of Shares Held by Shareholder

5,583,375

Debt instrument, face amount | $

$ 35,092,000

Issuance of treasury stock in settlement of convertible debt | $

$ 48,858,000

GS Direct [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Investment Owned, Balance, Shares

10,000,000

Incentive Plan [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, number of shares authorized (in Shares)

3,350,000

Incentive Stock Options [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Stock issued during period, shares, new issues (in Shares)

600,000

Share-based payment award, number of shares available for grant (in Shares)

1,145,834

2006 Equity Incentive Plan [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share based payment award equity instruments other than options additional grants in future (in Shares)

0

Restricted Stock [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Vested (in Dollars per share) | $ / shares

$ 20.89

Instruments grants in period (in shares)

1,343,929

Weighted average grant date fair value (in Dollars per share) | $ / shares

$ 17.30

Instruments vested in period (in shares)

536,958

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value | $ / shares

$ 13.65

$ 14.89

$ 13.65

Restricted Stock [Member] | Minimum [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, award vesting period

3 years

Restricted Stock [Member] | Maximum [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, award vesting period

4 years

Performance Shares [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, award vesting period

3 years

Instruments vested in period, fair value | $

$ 16,238,000

Instruments grants in period (in shares)

0

1,343,929

Weighted average grant date fair value (in Dollars per share) | $ / shares

$ 19.90

Restricted Stock and Performance Shares [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Instruments grants in period (in shares)

815,929

Executive Officer [Member] | Restricted Stock [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, award vesting period

4 years

Post-vesting holding period

2 years

Instruments number of persons granted shares (in shares) | senior_executive

2

Executive Officer [Member] | Performance Shares [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Equity instruments other than options, granted in period, fair value | $

$ 7,008,000

Weighted average grant date fair value (in Dollars per share) | $ / shares

$ 13.27

Executive Officer [Member] | Restricted Stock and Performance Shares [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Instruments grants in period (in shares)

528,000

Scenario, Forecast [Member] | Executive Officer [Member] | Restricted Stock [Member] | Minimum [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Instruments vested in period (in shares)

384,000

Scenario, Forecast [Member] | Executive Officer [Member] | Restricted Stock [Member] | Maximum [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Instruments vested in period (in shares)

528,000

Subsequent Event [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Dividends payable, amount per share (in Dollars per share) | $ / shares

$ 0.0725

Convert. debt due 2017 [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Debt instrument, face amount | $

$ 100,000,000

Debt Instrument, Interest Rate, Stated Percentage

4.00%

ESOP Loans [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Stock issued during period, value, ESOP | $

$ 10,908,000

ESOP, weighted average purchase price of shares purchased (in Dollars per share) | $ / shares

$ 17.54

Incentive Plan [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Share-based payment award, number of shares authorized (in Shares)

1,000,000

Senior Notes Two Thousand Twenty Two [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Debt instrument, face amount | $

$ 600,000,000

Debt Instrument, Interest Rate, Stated Percentage

5.25%

5.25%

5.25%

Original debt, amount | $

$ 125,000,000

Convertible Notes 2017 [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Debt Conversion, Converted Instrument, Amount | $

$ 173,855,000

Debt conversion, converted instrument, cash received | $

125,000,000

Issuance of treasury stock in settlement of convertible debt | $

$ 48,858,000

Converted instrument, shares issued

1,954,993,000

Special Dividends [Member]

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) [Line Items]

Common stock, dividends, per share, cash paid (in Dollars per share) | $ / shares

$ 1

Common Stock, Dividends, Per Share, Declared | $ / shares

$ 1

Dividends, Common Stock, Cash | $

$ 38,073,000

Payments of Dividends | $

$ 38,073,000

STOCKHOLDERS' EQUITY AND EQUI_4

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) - Summary of stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Stockholders' Equity Note [Abstract]
Pre-tax compensation expense	$ 10,078	$ 8,090	$ 10,136
Tax benefit	(2,469)	(2,836)	(3,553)
Total stock-based compensation expense, net of tax	$ 7,609	$ 5,254	$ 6,583

STOCKHOLDERS' EQUITY AND EQUI_5

STOCKHOLDERS' EQUITY AND EQUITY COMPENSATION (Details) - Summary of restricted stock activity - Restricted Stock [Member]	12 Months Ended
	Sep. 30, 2018$ / sharesshares
Shares
Unvested (in Shares) | shares	2,255,796
Granted (in Shares) | shares	1,343,929
Vested (in Shares) | shares	(536,958)
Forfeited (in Shares) | shares	(212,939)
Unvested (in Shares) | shares	2,849,828
Weighted Average Grant- Date Fair Value
Unvested (in Dollars per share) | $ / shares	$ 13.65
Granted (in Dollars per share) | $ / shares	17.30
Vested (in Dollars per share) | $ / shares	20.89
Forfeited (in Dollars per share) | $ / shares	20.91
Unvested (in Dollars per share) | $ / shares	$ 14.89

COMMITMENTS AND CONTINGENT LI_2

COMMITMENTS AND CONTINGENT LIABILITIES (Details) - USD ($)	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Aug. 31, 2009
Commitments and Contingencies Disclosure [Abstract]
Operating leases, rent expense, net	$ 35,726,000	$ 26,297,000	$ 26,180,000
Aggregate future minimum lease payments for operating leases in 2018	32,189,000
Aggregate future minimum lease payments for operating leases in 2019	26,365,000
Aggregate future minimum lease payments for operating leases in 2020	16,600,000
Aggregate future minimum lease payments for operating leases in 2021	10,811,000
Aggregate future minimum lease payments for operating leases in 2022	6,082,000
Aggregate future minimum lease payments for operating leases thereafter	12,135,000
Purchase obligation, due in next twelve months	226,026,000
Purchase obligation due in second year	5,569,000
Purchase obligation due in third year	2,000
Purchase obligation due in fourth year	1,000
Purchase obligation due in fifth year	1,470,000
Net capital cost value				$ 5,000,000
Obligation under consent order	$ 0
Net capital cost value in proposed remedial action plan				$ 10,000,000

EARNINGS PER SHARE EARNINGS P_2

EARNINGS PER SHARE EARNINGS PER SHARE (Details) - Basic and diluted EPS from continuing operations - shares shares in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
EARNINGS (LOSS) PER SHARE (Details) - Basic and diluted EPS from continuing operations [Line Items]
Weighted average shares outstanding - basic	41,005	41,005	41,074
Incremental shares from stock based compensation	1,417	1,642	2,326
Convertible debt due 2017	0	364	709
Weighted average shares outstanding - diluted	42,422	43,011	44,109
Employee Stock Option [Member]
EARNINGS (LOSS) PER SHARE (Details) - Basic and diluted EPS from continuing operations [Line Items]
Anti-dilutive awards excluded from diluted EPS computation	0	0	6

RELATED PARTIES (Details)

RELATED PARTIES (Details) - USD ($) $ in Thousands	Oct. 02, 2017	Jun. 19, 2018	Nov. 16, 2017	Nov. 15, 2017	May 18, 2016	Feb. 27, 2014	Dec. 31, 2008
RELATED PARTIES (Details) [Line Items]
Common Stock, Number of Shares Held by Shareholder		5,583,375
GS Direct [Member]
RELATED PARTIES (Details) [Line Items]
Investment Owned, Balance, Shares							10,000,000
Discontinued Operations, Held-for-sale [Member] | Plastics [Member]
RELATED PARTIES (Details) [Line Items]
Disposal group, including discontinued operation, consideration			$ 475,000	$ 475,000
Senior Notes Two Thousand Twenty Two [Member]
RELATED PARTIES (Details) [Line Items]
Stated percentage	5.25%				5.25%	5.25%
Senior note due 2022 [Member] | Senior notes [Member]
RELATED PARTIES (Details) [Line Items]
Proceeds from issuance of debt	$ 275,000
Stated percentage						5.25%

QUARTERLY FINANCIAL INFORMATI_3

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
Acquisition related costs	$ 2,320,000	$ 378,000	$ 2,348,000		$ 6,145,000
Proceeds from life insurance policy			$ 248
Special dividend ESOP charges	2,125,000
Equity offering costs	$ 795			$ 1,205,000	0	$ 0
Contract settlement charges					$ 3,300,000

QUARTERLY FINANCIAL INFORMATI_4

QUARTERLY FINANCIAL INFORMATION (UNAUDITED) (Details) - Schedule of quarterly financial information - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 545,505	$ 516,550	$ 478,560	$ 437,303	$ 430,799	$ 358,114	$ 383,807	$ 352,277	$ 1,977,918	$ 1,524,997	$ 1,477,035
Gross Profit	148,451	138,792	121,473	120,844	114,519	97,984	98,869	96,744	529,560	408,116	400,693
Income from continuing operations	$ 1,031	$ 7,442	$ 1,951	$ 22,831	$ 4,337	$ 4,452	$ 1,950	$ 7,044	$ 33,255	$ 17,783	$ 19,781
Per Share - Basic (in usd per share)	$ 0.03	$ 0.18	$ 0.05	$ 0.54	$ 0.10	$ 0.11	$ 0.05	$ 0.18	$ 0.81	$ 0.43	$ 0.48
Per Share - Diluted (in usd per share)	$ 0.02	$ 0.18	$ 0.05	$ 0.53	$ 0.10	$ 0.10	$ 0.05	$ 0.17	$ 0.78	$ 0.41	$ 0.45

REPORTABLE SEGMENTS (Details) -

REPORTABLE SEGMENTS (Details) - Schedule of Summary of Reconciliation of Segment Profit Before Taxes and Operations - USD ($)	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenue	$ 545,505,000	$ 516,550,000	$ 478,560,000	$ 437,303,000	$ 430,799,000	$ 358,114,000	$ 383,807,000	$ 352,277,000	$ 1,977,918,000	$ 1,524,997,000	$ 1,477,035,000
Income from continuing operations									96,450,000	69,027,000	82,340,000
Net interest expense									(63,871,000)	(51,449,000)	(49,877,000)
Unallocated amounts									(45,812,000)	(42,398,000)	(40,393,000)
Acquisition costs		(2,320,000)	$ (378,000)	$ (2,348,000)						(6,145,000)
Special Dividend ESOP Charges		(2,125,000)
Income (loss) before taxes from continuing operations									33,810,000	16,698,000	32,213,000
Loss on pension settlement									0	5,137,000	0
Equity Offering Costs		$ (795)							(1,205,000)	0	0
Total Segment adjusted EBITDA from continuing operations									213,463,000	172,697,000	168,334,000
Segment depreciation and amortization									(55,334,000)	(47,398,000)	(45,851,000)
Acquisition costs									(7,597,000)	(9,617,000)	0
Income (loss) before taxes from continuing operations									33,810,000	16,698,000	32,213,000
Consolidated depreciation and amortization									55,803,000	47,878,000	46,342,000
Capital expenditures									50,138,000	34,937,000	59,276,000
AMES [Member]
Segment Reporting Information [Line Items]
Revenue									953,612,000	545,269,000	513,973,000
CBP [Member]
Segment Reporting Information [Line Items]
Revenue									697,969,000	568,001,000	527,370,000
Home & Building Products [Member]
Segment Reporting Information [Line Items]
Revenue									1,651,581,000	1,113,270,000	1,041,343,000
Segment adjusted EBITDA									177,400,000	126,766,000	114,949,000
Segment depreciation and amortization									(44,533,000)	(36,547,000)	(35,267,000)
Capital expenditures									36,587,000	24,476,000	49,351,000
Telephonics [Member]
Segment Reporting Information [Line Items]
Revenue									326,337,000	411,727,000	435,692,000
Segment adjusted EBITDA									36,063,000	45,931,000	53,385,000
Segment depreciation and amortization									(10,801,000)	(10,851,000)	(10,584,000)
Capital expenditures									10,941,000	8,204,000	9,007,000
Operating [Member]
Segment Reporting Information [Line Items]
Capital expenditures									47,528,000	32,680,000	58,358,000
Corporate [Member]
Segment Reporting Information [Line Items]
Consolidated depreciation and amortization									469,000	480,000	491,000
Capital expenditures									2,610,000	2,257,000	918,000
Continuing Operations [Member]
Segment Reporting Information [Line Items]
Segment operating profit from continuing operations									155,749,000	119,438,000	122,483,000
Net interest expense									(63,871,000)	(51,449,000)	(49,877,000)
Unallocated amounts									(45,812,000)	(42,398,000)	(40,393,000)
Acquisition costs									(5,217,000)	(8,893,000)	0
Special Dividend ESOP Charges									(3,220,000)	0	0
Income (loss) before taxes from continuing operations									33,810,000	16,698,000	32,213,000
Equity Offering Costs									(1,205,000)	0	0
Continuing Operations [Member] | Home & Building Products [Member]
Segment Reporting Information [Line Items]
Income from continuing operations									130,487,000	89,495,000	79,682,000
Continuing Operations [Member] | Telephonics [Member]
Segment Reporting Information [Line Items]
Income from continuing operations									25,262,000	29,943,000	42,801,000
Postretirement Life Insurance [Member] | Continuing Operations [Member]
Segment Reporting Information [Line Items]
Loss on pension settlement									$ (2,614,000)	$ 0	$ 0

REPORTABLE SEGMENTS (Details)_2

REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets [Line Items]
Continuing assets	$ 2,081,650	$ 1,499,528	$ 1,417,185
Assets of discontinued operations	3,240	374,013	364,911
Total Assets	2,084,890	1,873,541	1,782,096
Home & Building Products [Member]
REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets [Line Items]
Continuing assets	1,631,631	1,084,103	1,020,297
Telephonics [Member]
REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets [Line Items]
Continuing assets	346,907	343,445	334,631
Operating [Member]
REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets [Line Items]
Continuing assets	1,978,538	1,427,548	1,354,928
Corporate [Member]
REPORTABLE SEGMENTS (Details) - Schedule of summary of segment assets [Line Items]
Continuing assets	$ 103,112	$ 71,980	$ 62,257

REPORTABLE SEGMENTS (Details)_3

REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue	$ 545,505	$ 516,550	$ 478,560	$ 437,303	$ 430,799	$ 358,114	$ 383,807	$ 352,277	$ 1,977,918	$ 1,524,997	$ 1,477,035
Consolidated property, plant and equipment, net	713,351				437,262				713,351	437,262	434,854
United States [Member]
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue									1,521,187	1,164,958	1,149,448
Consolidated property, plant and equipment, net	612,294				358,795				612,294	358,795	370,332
Europe [Member]
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue									102,814	67,048	68,604
AUSTRALIA
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue									166,980	124,757	106,780
Consolidated property, plant and equipment, net	33,288				35,917				33,288	35,917	26,196
UNITED KINGDOM
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated property, plant and equipment, net	24,892				4,144				24,892	4,144	0
MEXICO
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated property, plant and equipment, net	7,017				0				7,017	0	0
Canada [Member]
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue									123,341	106,080	102,333
Consolidated property, plant and equipment, net	33,884				36,383				33,884	36,383	35,984
All other countries [Member]
REPORTABLE SEGMENTS (Details) - Schedule of Segment Information by Geographic Region [Line Items]
Consolidated revenue									63,596	62,154	49,870
Consolidated property, plant and equipment, net	$ 1,976				$ 2,023				$ 1,976	$ 2,023	$ 2,342

REPORTABLE SEGMENTS (Details)

REPORTABLE SEGMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Nov. 16, 2017	Nov. 15, 2017
Home & Building Products [Member]
REPORTABLE SEGMENTS (Details) [Line Items]
Concentration risk, percentage	19.00%	17.00%	17.00%
Telephonics [Member]
REPORTABLE SEGMENTS (Details) [Line Items]
Concentration risk, percentage	10.00%	18.00%	21.00%
Discontinued Operations, Held-for-sale [Member] | Plastics [Member]
REPORTABLE SEGMENTS (Details) [Line Items]
Disposal group, including discontinued operation, consideration				$ 475,000	$ 475,000

OTHER INCOME (EXPENSE) (Details

OTHER INCOME (EXPENSE) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Other Income and Expenses [Abstract]
Currency exchange gains (losses)	$ (200)	$ (723)	$ (550)
Investment income (loss)	$ 1,184	$ 53	$ 316

OTHER COMPREHENSIVE INCOME (L_3

OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Summary of Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments, Pre-tax	$ 9,403	$ 10,667	$ 17,284
Pension and other defined benefit plans, Pre-tax	24,081	14,160	(8,694)
Cash flow hedge, Pre-tax	900	1,370	(2,593)
Total other comprehensive income (loss), Pre-tax	34,384	26,197	5,997
Foreign currency translation adjustments, Tax	0	0	0
Pension and other defined benefit plans, Tax	(7,700)	(4,957)	3,043
Cash flow hedge, Tax	(315)	(480)	907
Total other comprehensive income (loss), Tax	(8,015)	(5,437)	3,950
Foreign currency translation adjustments, Net of Tax	9,403	10,667	17,284
Pension and other defined benefit plans, Net of Tax	16,381	9,203	(5,651)
Cash flow hedge, Net of Tax	585	890	(1,686)
Total other comprehensive income, net of taxes	$ 26,369	$ 20,760	$ 9,947

OTHER COMPREHENSIVE INCOME (L_4

OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Accumulated Other Comprehensive Income - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (34,112)	$ (60,481)
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(22,824)	(32,227)
Pension and other defined benefit plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(11,759)	(28,140)
Cash flow hedge [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ 471	$ (114)

OTHER COMPREHENSIVE INCOME (L_5

OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Total Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net income	$ 125,678	$ 14,912	$ 30,010
Other comprehensive income (loss), net of taxes	26,369	20,760	9,947
Comprehensive income	$ 152,047	$ 35,672	$ 39,957

OTHER COMPREHENSIVE INCOME (L_6

OTHER COMPREHENSIVE INCOME (LOSS) (Details) - Summary of Amounts Reclassified from Accumulated Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension amortization	$ (1,397)	$ (3,343)	$ (2,375)
Cash flow hedges	657	(1,458)	(752)
Total before tax	(740)	(4,801)	(3,127)
Tax	155	1,680	1,094
Net of tax	$ (585)	$ (3,121)	$ (2,033)

CONSOLIDATING GUARANTOR AND N_3

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details)	12 Months Ended
	Sep. 30, 2018
Clopay Ames True Temper Holding, Corp. [Member]
Condensed Financial Statements, Captions [Line Items]
Subsidiary percentage ownership	100.00%
AMES Southern, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Subsidiary percentage ownership	100.00%
The AMES Companies, Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Subsidiary percentage ownership	100.00%
Telephonics Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Subsidiary percentage ownership	100.00%
Clopay Building Products [Member]
Condensed Financial Statements, Captions [Line Items]
Subsidiary percentage ownership	100.00%

CONSOLIDATING GUARANTOR AND N_4

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated balance sheets - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
CURRENT ASSETS
Cash and equivalents	$ 69,758	$ 47,681	$ 72,553	$ 52,001
Accounts receivable, net of allowances	280,509	208,229
Contract costs and recognized income not yet billed, net of progress payments	121,803	131,662
Inventories	398,359	299,437
Prepaid and other current assets	42,121	40,067
Assets of discontinued operations held for sale	0	370,724
Assets of discontinued operations not held for sale	324	329
Total Current Assets	912,874	1,098,129
PROPERTY, PLANT AND EQUIPMENT, net	342,492	232,135
GOODWILL	439,395	319,139	306,163
INTANGIBLE ASSETS, net	370,858	205,127
INTERCOMPANY RECEIVABLE	0	0
EQUITY INVESTMENTS IN SUBSIDIARIES	0	0
OTHER ASSETS	16,355	16,051
ASSETS OF DISCONTINUED OPERATIONS	2,916	2,960
Total Assets	2,084,890	1,873,541	1,782,096
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	13,011	11,078
Accounts payable and accrued liabilities	372,850	267,209
Liabilities of discontinued operations held for sale	0	84,450
Liabilities of discontinued operations	7,210	8,342
Total Current Liabilities	393,071	371,079
LONG-TERM DEBT, net of debt discounts	1,108,071	968,080
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	106,710	132,537
LIABILITIES OF DISCONTINUED OPERATIONS	2,647	3,037
Total Liabilities	1,610,499	1,474,733
SHAREHOLDERS’ EQUITY	474,391	398,808	410,947	430,525
Total Liabilities and Shareholders’ Equity	2,084,890	1,873,541
Parent Company [Member]
CURRENT ASSETS
Cash and equivalents	15,976	3,240	6,517	2,440
Accounts receivable, net of allowances	0	0
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories	0	0
Prepaid and other current assets	12,179	21,131
Assets of discontinued operations held for sale		0
Assets of discontinued operations not held for sale	0	0
Total Current Assets	28,155	24,371
PROPERTY, PLANT AND EQUIPMENT, net	936	645
GOODWILL	6,646	0
INTANGIBLE ASSETS, net	93	93
INTERCOMPANY RECEIVABLE	56,396	552,017
EQUITY INVESTMENTS IN SUBSIDIARIES	1,528,932	863,149
OTHER ASSETS	8,651	12,171
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	1,629,809	1,452,446
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	2,276	2,854
Accounts payable and accrued liabilities	26,639	14,683
Liabilities of discontinued operations held for sale		0
Liabilities of discontinued operations	0	0
Total Current Liabilities	28,915	17,537
LONG-TERM DEBT, net of debt discounts	1,044,071	903,609
INTERCOMPANY PAYABLES	66,058	84,068
OTHER LIABILITIES	16,374	48,424
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	1,155,418	1,053,638
SHAREHOLDERS’ EQUITY	474,391	398,808
Total Liabilities and Shareholders’ Equity	1,629,809	1,452,446
Guarantor Subsidiaries [Member]
CURRENT ASSETS
Cash and equivalents	16,353	8,066	27,692	10,672
Accounts receivable, net of allowances	234,885	168,731
Contract costs and recognized income not yet billed, net of progress payments	121,393	131,383
Inventories	332,067	246,605
Prepaid and other current assets	21,313	15,854
Assets of discontinued operations held for sale		168,306
Assets of discontinued operations not held for sale	0	0
Total Current Assets	726,011	738,945
PROPERTY, PLANT AND EQUIPMENT, net	299,920	200,362
GOODWILL	361,507	280,797
INTANGIBLE ASSETS, net	293,093	143,415
INTERCOMPANY RECEIVABLE	314,394	757,608
EQUITY INVESTMENTS IN SUBSIDIARIES	968,330	877,641
OTHER ASSETS	15,942	12,054
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	2,979,197	3,010,822
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	3,398	1,471
Accounts payable and accrued liabilities	303,154	199,784
Liabilities of discontinued operations held for sale		47,426
Liabilities of discontinued operations	(22,327)	0
Total Current Liabilities	284,225	248,681
LONG-TERM DEBT, net of debt discounts	6,110	6,044
INTERCOMPANY PAYABLES	(77,760)	1,259,413
OTHER LIABILITIES	73,391	76,036
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	285,966	1,590,174
SHAREHOLDERS’ EQUITY	2,693,231	1,420,648
Total Liabilities and Shareholders’ Equity	2,979,197	3,010,822
Non-Guarantor Subsidiaries [Member]
CURRENT ASSETS
Cash and equivalents	37,429	36,375	38,344	38,889
Accounts receivable, net of allowances	69,729	59,929
Contract costs and recognized income not yet billed, net of progress payments	410	279
Inventories	66,373	52,759
Prepaid and other current assets	6,168	3,002
Assets of discontinued operations held for sale		202,418
Assets of discontinued operations not held for sale	324	329
Total Current Assets	180,433	355,091
PROPERTY, PLANT AND EQUIPMENT, net	41,636	31,128
GOODWILL	71,242	38,342
INTANGIBLE ASSETS, net	77,672	61,619
INTERCOMPANY RECEIVABLE	(121,445)	915,551
EQUITY INVESTMENTS IN SUBSIDIARIES	3,347,894	1,613,891
OTHER ASSETS	374	(1,002)
ASSETS OF DISCONTINUED OPERATIONS	2,916	2,960
Total Assets	3,600,722	3,017,580
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	7,337	6,753
Accounts payable and accrued liabilities	59,531	46,111
Liabilities of discontinued operations held for sale		37,024
Liabilities of discontinued operations	29,537	8,342
Total Current Liabilities	96,405	98,230
LONG-TERM DEBT, net of debt discounts	57,890	58,427
INTERCOMPANY PAYABLES	263,227	854,518
OTHER LIABILITIES	20,592	14,135
LIABILITIES OF DISCONTINUED OPERATIONS	2,647	3,037
Total Liabilities	440,761	1,028,347
SHAREHOLDERS’ EQUITY	3,159,961	1,989,233
Total Liabilities and Shareholders’ Equity	3,600,722	3,017,580
Consolidation, Eliminations [Member]
CURRENT ASSETS
Cash and equivalents	0	0	$ 0	$ 0
Accounts receivable, net of allowances	(24,105)	(20,431)
Contract costs and recognized income not yet billed, net of progress payments	0	0
Inventories	(81)	73
Prepaid and other current assets	2,461	80
Assets of discontinued operations held for sale		0
Assets of discontinued operations not held for sale	0	0
Total Current Assets	(21,725)	(20,278)
PROPERTY, PLANT AND EQUIPMENT, net	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, net	0	0
INTERCOMPANY RECEIVABLE	(249,345)	(2,225,176)
EQUITY INVESTMENTS IN SUBSIDIARIES	(5,845,156)	(3,354,681)
OTHER ASSETS	(8,612)	(7,172)
ASSETS OF DISCONTINUED OPERATIONS	0	0
Total Assets	(6,124,838)	(5,607,307)
CURRENT LIABILITIES
Notes payable and current portion of long-term debt	0	0
Accounts payable and accrued liabilities	(16,474)	6,631
Liabilities of discontinued operations held for sale		0
Liabilities of discontinued operations	0	0
Total Current Liabilities	(16,474)	6,631
LONG-TERM DEBT, net of debt discounts	0	0
INTERCOMPANY PAYABLES	(251,525)	(2,197,999)
OTHER LIABILITIES	(3,647)	(6,058)
LIABILITIES OF DISCONTINUED OPERATIONS	0	0
Total Liabilities	(271,646)	(2,197,426)
SHAREHOLDERS’ EQUITY	(5,853,192)	(3,409,881)
Total Liabilities and Shareholders’ Equity	$ (6,124,838)	$ (5,607,307)

CONSOLIDATING GUARANTOR AND N_5

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated statement of operations and comprehensive income - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Condensed Income Statements, Captions [Line Items]
Revenue	$ 545,505	$ 516,550	$ 478,560	$ 437,303	$ 430,799	$ 358,114	$ 383,807	$ 352,277	$ 1,977,918	$ 1,524,997	$ 1,477,035
Cost of goods and services									1,448,358	1,116,881	1,076,342
Gross profit	148,451	138,792	121,473	120,844	114,519	97,984	98,869	96,744	529,560	408,116	400,693
Selling, general and administrative expenses									433,110	339,089	318,353
Restructuring and other related charges										0	0
Total operating expenses										339,089	318,353
Income from continuing operations									96,450	69,027	82,340
Other income (expense)
Interest income (expense), net									(63,871)	(51,449)	(49,877)
Other, net									1,231	(880)	(250)
Total other income (expense)									(62,640)	(52,329)	(50,127)
Income before taxes from continuing operations									33,810	16,698	32,213
Provision (benefit) for income taxes									555	(1,085)	12,432
Income (loss) before equity in net income of subsidiaries									33,255	17,783	19,781
Equity in net income (loss) of subsidiaries									0	0	0
Income (loss) from continuing operations	$ 1,031	$ 7,442	$ 1,951	$ 22,831	$ 4,337	$ 4,452	$ 1,950	$ 7,044	33,255	17,783	19,781
Income from operations of discontinued businesses									119,981	22,276	20,952
Provision for income taxes									27,558	25,147	10,723
Income (loss) from discontinued operations									92,423	(2,871)	10,229
Net income									125,678	14,912	30,010
Other comprehensive income, net of tax									26,369	20,760	9,947
Comprehensive income (loss)									152,047	35,672	39,957
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenue									0	0	0
Cost of goods and services									0	0	0
Gross profit									0	0	0
Selling, general and administrative expenses									38,691	42,273	26,427
Restructuring and other related charges										0	0
Total operating expenses										42,273	26,427
Income from continuing operations									(38,691)	(42,273)	(26,427)
Other income (expense)
Interest income (expense), net									(23,911)	(13,804)	(12,549)
Other, net									(6,515)	59	337
Total other income (expense)									(30,426)	(13,745)	(12,212)
Income before taxes from continuing operations									(69,117)	(56,018)	(38,639)
Provision (benefit) for income taxes									(17,692)	(11,338)	4,964
Income (loss) before equity in net income of subsidiaries									(51,425)	(44,680)	(43,603)
Equity in net income (loss) of subsidiaries									177,103	59,592	73,613
Income (loss) from continuing operations									125,678	14,912	30,010
Income from operations of discontinued businesses									0	0	0
Provision for income taxes									0	0	0
Income (loss) from discontinued operations									0	0	0
Net income									125,678	14,912	30,010
Comprehensive income (loss)									152,047	35,672	39,957
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenue									1,638,792	1,284,189	1,277,241
Cost of goods and services									1,232,019	966,293	952,296
Gross profit									406,773	317,896	324,945
Selling, general and administrative expenses									303,856	232,720	228,961
Restructuring and other related charges										0	1,299
Total operating expenses										232,720	230,260
Income from continuing operations									102,917	85,176	94,685
Other income (expense)
Interest income (expense), net									(31,913)	(24,242)	(24,050)
Other, net									120,670	1,395	1,862
Total other income (expense)									88,757	(22,847)	(22,188)
Income before taxes from continuing operations									191,674	62,329	72,497
Provision (benefit) for income taxes									9,546	24,560	29,445
Income (loss) before equity in net income of subsidiaries									182,128	37,769	43,052
Equity in net income (loss) of subsidiaries									(151,864)	(25,231)	(2,858)
Income (loss) from continuing operations									30,264	12,538	40,194
Income from operations of discontinued businesses									119,981	16,827	15,625
Provision for income taxes									27,558	4,476	4,720
Income (loss) from discontinued operations									92,423	12,351	10,905
Net income									122,687	24,889	51,099
Comprehensive income (loss)									143,936	35,575	44,391
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenue									367,149	270,520	228,350
Cost of goods and services									245,687	181,634	154,181
Gross profit									121,462	88,886	74,169
Selling, general and administrative expenses									90,933	64,466	63,335
Restructuring and other related charges										0	(1,299)
Total operating expenses										64,466	62,036
Income from continuing operations									30,529	24,420	12,133
Other income (expense)
Interest income (expense), net									(8,047)	(13,403)	(13,278)
Other, net									(111,187)	(630)	(500)
Total other income (expense)									(119,234)	(14,033)	(13,778)
Income before taxes from continuing operations									(88,705)	10,387	(1,645)
Provision (benefit) for income taxes									8,743	(14,307)	(21,977)
Income (loss) before equity in net income of subsidiaries									(97,448)	24,694	20,332
Equity in net income (loss) of subsidiaries									182,128	37,770	43,052
Income (loss) from continuing operations									84,680	62,464	63,384
Income from operations of discontinued businesses									0	5,449	5,327
Provision for income taxes									0	20,671	6,003
Income (loss) from discontinued operations									0	(15,222)	(676)
Net income									84,680	47,242	62,708
Comprehensive income (loss)									81,389	38,337	90,560
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Revenue									(28,023)	(29,712)	(28,556)
Cost of goods and services									(29,348)	(31,046)	(30,135)
Gross profit									1,325	1,334	1,579
Selling, general and administrative expenses									(370)	(370)	(370)
Restructuring and other related charges										0	0
Total operating expenses										(370)	(370)
Income from continuing operations									1,695	1,704	1,949
Other income (expense)
Interest income (expense), net									0	0	0
Other, net									(1,737)	(1,704)	(1,949)
Total other income (expense)									(1,737)	(1,704)	(1,949)
Income before taxes from continuing operations									(42)	0	0
Provision (benefit) for income taxes									(42)	0	0
Income (loss) before equity in net income of subsidiaries									0	0	0
Equity in net income (loss) of subsidiaries									(207,367)	(72,131)	(113,807)
Income (loss) from continuing operations									(207,367)	(72,131)	(113,807)
Income from operations of discontinued businesses									0	0	0
Provision for income taxes									0	0	0
Income (loss) from discontinued operations									0	0	0
Net income									(207,367)	(72,131)	(113,807)
Comprehensive income (loss)									$ (225,325)	$ (73,912)	$ (134,951)

CONSOLIDATING GUARANTOR AND N_6

CONSOLIDATING GUARANTOR AND NON-GUARANTOR FINANCIAL INFORMATION (Details) - Summary of consolidated cash flows - USD ($)	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 125,678,000	$ 14,912,000	$ 30,010,000
Net (income) loss from discontinued operations	(92,423,000)	2,871,000	(10,229,000)
Net cash provided by (used in) operating activities	66,446,000	49,151,000	80,118,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(50,138,000)	(34,937,000)	(59,276,000)
Acquired business, net of cash acquired	(430,932,000)	(34,719,000)	(4,470,000)
Intercompany distributions	0		4,470,000
Proceeds from Divestiture of Businesses	474,727,000	0	0
Proceeds from sale of property, plant and equipment	663,000	143,000	770,000
Investment purchases	0	1,824,000	(715,000)
Net cash used in investing activities - continuing operations	(5,680,000)	(71,337,000)	(62,261,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0	0	0
Purchase of shares for treasury	(45,605,000)	(15,841,000)	(65,307,000)
Proceeds from long-term debt	443,058,000	233,443,000	302,362,000
Payments of long-term debt	(300,993,000)	(170,454,000)	(208,514,000)
Share premium payment on settled debt	0	(24,997,000)	0
Change in short-term borrowings	144,000	0	0
Financing costs	(7,793,000)	(1,548,000)	(4,384,000)
Purchase of ESOP shares	0	(10,908,000)	0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	(49,797,000)	(10,325,000)	(8,798,000)
Other, net	51,000	(70,000)	55,000
Net cash provided by (used) in financing activities - continuing operations	39,065,000	(700,000)	15,414,000
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	(78,927,000)	(2,150,000)	(13,605,000)
Effect of exchange rate changes on cash and equivalents	1,173,000	164,000	886,000
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	22,077,000	(24,872,000)	20,552,000
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	47,681,000	72,553,000	52,001,000
CASH AND EQUIVALENTS AT END OF PERIOD	69,758,000	47,681,000	72,553,000
Parent Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	125,678,000	14,912,000	30,010,000
Net (income) loss from discontinued operations	0	0	0
Net cash provided by (used in) operating activities	389,671,000	(10,771,000)	(11,879,000)
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(544,000)	(15,000)	(259,000)
Acquired business, net of cash acquired	(368,936,000)	0
Intercompany distributions	0		0
Proceeds from Divestiture of Businesses	0
Proceeds from sale of property, plant and equipment	0	0	0
Investment purchases		1,824,000	(715,000)
Net cash used in investing activities - continuing operations	(369,480,000)	(1,839,000)	456,000
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0
Purchase of shares for treasury	(45,605,000)	(15,841,000)	(65,307,000)
Proceeds from long-term debt	411,623,000	201,124,000	271,340,000
Payments of long-term debt	(269,478,000)	(149,109,000)	(177,513,000)
Share premium payment on settled debt		(24,997,000)
Change in short-term borrowings	0	0	0
Financing costs	(7,793,000)	(1,548,000)	(4,277,000)
Purchase of ESOP shares		(10,908,000)
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	(49,797,000)	(10,325,000)	(8,798,000)
Other, net	(46,405,000)	20,937,000	55,000
Net cash provided by (used) in financing activities - continuing operations	(7,455,000)	9,333,000	15,500,000
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	0	0	0
Effect of exchange rate changes on cash and equivalents	0	0	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	12,736,000	(3,277,000)	4,077,000
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	3,240,000	6,517,000	2,440,000
CASH AND EQUIVALENTS AT END OF PERIOD	15,976,000	3,240,000	6,517,000
Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	122,687,000	24,889,000	51,099,000
Net (income) loss from discontinued operations	(92,423,000)	(12,351,000)	(10,905,000)
Net cash provided by (used in) operating activities	(405,174,000)	56,320,000	87,252,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(41,531,000)	(27,902,000)	(62,176,000)
Acquired business, net of cash acquired	(4,843,000)	0
Intercompany distributions	0		2,726,000
Proceeds from Divestiture of Businesses	474,727,000
Proceeds from sale of property, plant and equipment	62,000	144,000	763,000
Investment purchases		0	0
Net cash used in investing activities - continuing operations	428,415,000	(27,758,000)	(64,139,000)
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	2,125,000	0	2,311,000
Payments of long-term debt	(5,403,000)	(1,282,000)	(1,237,000)
Share premium payment on settled debt		0
Change in short-term borrowings	144,000	0	0
Financing costs	0	0	0
Purchase of ESOP shares		0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	0	0	0
Other, net	4,733,000	(34,806,000)	(1,926,000)
Net cash provided by (used) in financing activities - continuing operations	1,599,000	(36,088,000)	(852,000)
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	(16,394,000)	(12,100,000)	(5,241,000)
Effect of exchange rate changes on cash and equivalents	(159,000)	0	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	8,287,000	(19,626,000)	17,020,000
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	8,066,000	27,692,000	10,672,000
CASH AND EQUIVALENTS AT END OF PERIOD	16,353,000	8,066,000	27,692,000
Non-Guarantor Subsidiaries [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	84,680,000	47,242,000	62,708,000
Net (income) loss from discontinued operations	0	15,222,000	676,000
Net cash provided by (used in) operating activities	108,981,000	3,602,000	4,745,000
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	(8,063,000)	(7,020,000)	3,159,000
Acquired business, net of cash acquired	(57,153,000)	(34,719,000)
Intercompany distributions	0		1,744,000
Proceeds from Divestiture of Businesses	0
Proceeds from sale of property, plant and equipment	601,000	(1,000)	7,000
Investment purchases		0	0
Net cash used in investing activities - continuing operations	(64,615,000)	(41,740,000)	1,422,000
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	29,310,000	32,319,000	28,711,000
Payments of long-term debt	(26,112,000)	(20,063,000)	(29,764,000)
Share premium payment on settled debt		0
Change in short-term borrowings	0	0	0
Financing costs	0	0	(107,000)
Purchase of ESOP shares		0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	0	0	0
Other, net	14,691,000	13,799,000	1,926,000
Net cash provided by (used) in financing activities - continuing operations	17,889,000	26,055,000	766,000
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	(62,533,000)	9,950,000	(8,364,000)
Effect of exchange rate changes on cash and equivalents	1,332,000	164,000	886,000
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	1,054,000	(1,969,000)	(545,000)
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	36,375,000	38,344,000	38,889,000
CASH AND EQUIVALENTS AT END OF PERIOD	37,429,000	36,375,000	38,344,000
Consolidation, Eliminations [Member]
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	(207,367,000)	(72,131,000)	(113,807,000)
Net (income) loss from discontinued operations	0	0	0
Net cash provided by (used in) operating activities	(27,032,000)	0	0
CASH FLOWS FROM INVESTING ACTIVITIES - CONTINUING OPERATIONS:
Acquisition of property, plant and equipment	0	0	0
Acquired business, net of cash acquired	0	0
Intercompany distributions	0		0
Proceeds from Divestiture of Businesses	0
Proceeds from sale of property, plant and equipment	0	0	0
Investment purchases		0	0
Net cash used in investing activities - continuing operations	0	0	0
CASH FLOWS FROM FINANCING ACTIVITIES - CONTINUING OPERATIONS:
Proceeds from issuance of common stock	0
Purchase of shares for treasury	0	0	0
Proceeds from long-term debt	0	0	0
Payments of long-term debt	0	0	0
Share premium payment on settled debt		0
Change in short-term borrowings	0	0	0
Financing costs	0	0	0
Purchase of ESOP shares		0
Tax effect from exercise/vesting of equity awards, net	0		0
Dividends	0	0	0
Other, net	27,032,000	0	0
Net cash provided by (used) in financing activities - continuing operations	27,032,000	0	0
CASH FLOWS FROM DISCONTINUED OPERATIONS:
Net cash used in discontinued operations	0	0	0
Effect of exchange rate changes on cash and equivalents	0	0	0
NET INCREASE (DECREASE) IN CASH AND EQUIVALENTS	0	0	0
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	0	0	0
CASH AND EQUIVALENTS AT END OF PERIOD	$ 0	$ 0	$ 0

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details)	Nov. 14, 2018$ / shares
Subsequent Event [Member]
SUBSEQUENT EVENTS (Details) [Line Items]
Dividends payable, amount per share (in Dollars per share)	$ 0.0725

SCHEDULE II VALUATION AND QUA_2

SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS (Details) - Schedule of Valuation and Qualifying Accounts - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Segment Reporting Information [Line Items]
Balance at Beginning of Year	$ 5,966	$ 4,692	$ 3,905
Recorded to Cost and Expense	(5,920)	1,680	1,554
Accounts Written Off, net	5,219	(406)	(766)
Other	1,143	0	(1)
Balance at End of Year	6,408	5,966	4,692
Inventory valuation [Member]
Segment Reporting Information [Line Items]
Balance at Beginning of Year	16,419	15,338	13,003
Recorded to Cost and Expense	1,924	851	2,820
Accounts Written Off, net	(306)	203	(728)
Other	8,028	27	243
Balance at End of Year	26,065	16,419	15,338
Deferred tax valuation allowance [Member]
Segment Reporting Information [Line Items]
Balance at Beginning of Year	17,466	12,832	10,462
Recorded to Cost and Expense	(8,946)	4,634	2,370
Accounts Written Off, net	0	0	0
Other	0	0	0
Balance at End of Year	8,520	17,466	12,832
Bad debts [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Segment Reporting Information [Line Items]
Balance at Beginning of Year	1,109	1,217	1,628
Recorded to Cost and Expense	(40)	279	349
Accounts Written Off, net	11	(387)	(759)
Other	744	0	(1)
Balance at End of Year	1,824	1,109	1,217
Sales returns and allowances [Member] | SEC Schedule, 12-09, Allowance, Credit Loss [Member]
Segment Reporting Information [Line Items]
Balance at Beginning of Year	4,857	3,475	2,277
Recorded to Cost and Expense	(5,880)	1,401	1,205
Accounts Written Off, net	5,208	(19)	(7)
Other	399	0	0
Balance at End of Year	$ 4,584	$ 4,857	$ 3,475