LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate					6.00%
Cash Interest	$ 10,060		$ 11,730		$ 32,395		$ 34,795
Amort. Debt Discount	921		846		2,713		2,491
Amort. Deferred Cost & Other Fees	680		703		2,076		2,160
Total Interest Expense	11,661		13,279		37,184		39,446
Senior notes due 2018 [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate			7.40%	[1]	7.40%	[1]	7.40%	[1]
Cash Interest	0	[1]	9,797	[1]	15,930	[1]	29,391	[1]
Amort. Debt Discount	0	[1]	0	[1]	0	[1]	0	[1]
Amort. Deferred Cost & Other Fees	0	[1]	406	[1]	667	[1]	1,217	[1]
Total Interest Expense	0	[1]	10,203	[1]	16,597	[1]	30,608	[1]
Senior notes due 2022 [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	5.50%	[1]			5.50%	[1]
Cash Interest	7,875	[1]	0	[1]	10,675	[1]	0	[1]
Amort. Debt Discount	0	[1]	0	[1]	0	[1]	0	[1]
Amort. Deferred Cost & Other Fees	310	[1]	0	[1]	421	[1]	0	[1]
Total Interest Expense	8,185	[1]	0	[1]	11,096	[1]	0	[1]
Revolver due 2019 [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	309	[1]	179	[1]	782	[1]	603	[1]
Amort. Debt Discount	0	[1]	0	[1]	0	[1]	0	[1]
Amort. Deferred Cost & Other Fees	144	[1]	131	[1]	422	[1]	444	[1]
Total Interest Expense	453	[1]	310	[1]	1,204	[1]	1,047	[1]
Convert. debt due 2017 [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	9.10%	[2]	9.10%	[2]	9.10%	[2]	9.20%	[2]
Cash Interest	1,000	[2]	1,000	[2]	3,000	[2]	3,000	[2]
Amort. Debt Discount	921	[2]	846	[2]	2,713	[2]	2,491	[2]
Amort. Deferred Cost & Other Fees	112	[2]	110	[2]	333	[2]	332	[2]
Total Interest Expense	2,033	[2]	1,956	[2]	6,046	[2]	5,823	[2]
Real estate mortgages [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	3.80%	[3]	4.90%	[3]	4.00%	[3]	4.90%	[3]
Cash Interest	124	[3]	133	[3]	376	[3]	407	[3]
Amort. Debt Discount	0	[3]	0	[3]	0	[3]	0	[3]
Amort. Deferred Cost & Other Fees	35	[3]	22	[3]	108	[3]	65	[3]
Total Interest Expense	159	[3]	155	[3]	484	[3]	472	[3]
ESOP Loans [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	2.90%	[4]	2.80%	[4]	3.20%	[4]	2.90%	[4]
Cash Interest	192	[4]	151	[4]	524	[4]	476	[4]
Amort. Debt Discount	0	[4]	0	[4]	0	[4]	0	[4]
Amort. Deferred Cost & Other Fees	25	[4]	2	[4]	32	[4]	6	[4]
Total Interest Expense	217	[4]	153	[4]	556	[4]	482	[4]
Capital lease - real estate [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Effective Interest Rate	5.30%	[5]	5.30%	[5]	5.40%	[5]	5.30%	[5]
Cash Interest	112	[5]	125	[5]	345	[5]	381	[5]
Amort. Debt Discount	0	[5]	0	[5]	0	[5]	0	[5]
Amort. Deferred Cost & Other Fees	5	[5]	6	[5]	19	[5]	19	[5]
Total Interest Expense	117	[5]	131	[5]	364	[5]	400	[5]
Non U.S. lines of credit [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	307	[6]	155	[6]	724	[6]	415	[6]
Amort. Debt Discount	0	[6]	0	[6]	0	[6]	0	[6]
Amort. Deferred Cost & Other Fees	27	[6]	0	[6]	27	[6]	0	[6]
Total Interest Expense	334	[6]	155	[6]	751	[6]	415	[6]
Non U.S. term loans [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	273	[6]	109	[6]	426	[6]	415	[6]
Amort. Debt Discount	0	[6]	0	[6]	0	[6]	0	[6]
Amort. Deferred Cost & Other Fees	13	[6]	26	[6]	17	[6]	77	[6]
Total Interest Expense	286	[6]	135	[6]	443	[6]	492	[6]
Other long term debt [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	6	[7]	272	[7]	17	[7]	523	[7]
Amort. Debt Discount	0	[7]	0	[7]	0	[7]	0	[7]
Amort. Deferred Cost & Other Fees	9	[7]	0	[7]	30	[7]	0	[7]
Total Interest Expense	15	[7]	272	[7]	47	[7]	523	[7]
Capitalized interest [Member]
LONG-TERM DEBT (Details) - Summary of Interest Expense Incurred [Line Items]
Cash Interest	(138)		(191)		(404)		(816)
Amort. Debt Discount	0		0		0		0
Amort. Deferred Cost & Other Fees	0		0		0		0
Total Interest Expense	$ (138)		$ (191)		$ (404)		$ (816)

[1] On February 27, 2014, in an unregistered offering through a private placement under Rule 144A, Griffon issued, at par, $600,000 of 5.25% Senior Notes due 2022 (“Senior Notes”); interest is payable semi-annually on March 1 and September 1, starting September 1, 2014. Proceeds from the Senior Notes were used to redeem $550,000 of 7.125% senior notes due 2018, to pay a tender offer premium of $31,530 and to make interest payments of $16,716, with the balance used to pay a portion of the transaction fees and expenses. The Senior Notes are senior unsecured obligations of Griffon guaranteed by certain domestic subsidiaries, and subject to certain covenants, limitations and restrictions. On June 18, 2014, Griffon exchanged all of the Senior Notes for substantially identical Senior Notes registered under the Securities Act of 1933 via an exchange offer.In connection with these transactions, Griffon capitalized $9,950 of underwriting fees and other expenses incurred related to issuance of the Senior Notes, which will amortize over the term of such notes. Griffon recognized a loss on the early extinguishment of debt on the 7.125% senior notes aggregating $38,890, comprised of the $31,530 tender offer premium, the write-off of $6,574 of remaining deferred financing fees and $786 of prepaid interest on defeased notes. On February 14, 2014, Griffon amended its $225,000 Revolving Credit Facility (“Credit Agreement”) to extend its maturity date from March 28, 2018 to March 28, 2019, and to revise certain financial maintenance and negative covenants to improve Griffon's financial and operating flexibility. The facility includes a letter of credit sub-facility with a limit of $60,000, a multi-currency sub-facility of $50,000 and a swing line sub-facility with a limit of $30,000. 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 a default or 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. The current margins are 1.25% for base rate loans and 2.25% 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 Credit Agreement also includes certain restrictions, such as limitations on the ability of Griffon to incur indebtedness and liens and to 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 assets of the Company and the guarantors and a pledge of not greater than 65% of the equity interest in each of Griffon’s material, first-tier foreign subsidiaries (except that a lien on the assets of Griffon and its material domestic subsidiaries securing a limited amount of the debt under the ESOP credit agreement ranks pari passu with the lien granted on such assets under the Credit Agreement; see footnote (d) below). At June 30, 2014, outstanding borrowings and standby letters of credit were $25,000 and $20,365, respectively; $179,635 was available 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”). The current conversion rate of the 2017 Notes is 68.6238 shares of Griffon’s common stock per $1,000 principal amount of notes, corresponding to a conversion price of $14.53 per share. When a cash dividend is declared that would result in an adjustment to the conversion ratio of less than 1%, any adjustment to the conversion ratio is deferred until the first to occur of (i) actual conversion; (ii) the 42nd trading day prior to maturity of the notes; and (iii) such time as the cumulative adjustment equals or exceeds 1%. As of June 30, 2014, aggregate dividends since the last conversion price adjustment of $0.03 per share would have resulted in an adjustment to the conversion ratio of approximately .27%. At both June 30, 2014 and 2013, the 2017 Notes had a capital in excess of par component, net of tax, of $15,720.

[3] On October 21, 2013, Griffon refinanced two properties’ real estate mortgages to secure loans totaling $17,175. The loans mature in October 2018, are collateralized by the related properties and are guaranteed by Griffon. The loans bear interest at a rate of LIBOR plus 2.75%. At June 30, 2014, $16,603 was outstanding.

[4] In December 2013, Griffon’s Employee Stock Ownership Plan (“ESOP”) entered into a credit agreement which refinanced the two existing ESOP loans into one new Term Loan in the amount of $21,098. The agreement also provided a Line Note with $10,000 available to purchase shares of Griffon common stock in the open market through September 29, 2014. As of June 30, 2014, 749,977 shares of Griffon common stock, for a total of $10,000, were purchased with proceeds from the Line Note. In March 2014, the Line Note was combined with the Term Loan to form one new term loan. The loan bears interest at a) LIBOR plus 2.25% or b) the lender’s prime rate, at Griffon’s option. The loan requires quarterly principal payments of $505 through September 30, 2014 and $419 per quarter thereafter, with a balloon payment of approximately $22,400 due at maturity in December 2018. The loan is secured by shares purchased with the proceeds of the loan and with a lien on the assets of Griffon and its material domestic subsidiaries securing a limited amount of the loan (which lien ranks pari passu with the lien granted on such assets securing the debt under Griffon’s revolving credit facility; see footnote (a) above), and Griffon guarantees repayment. As of June 30, 2014, $29,583 was outstanding.In July 2014, Griffon's ESOP entered into an amendment to the existing agreement which provides for an additional $10,000 Line Note available to purchase shares in the open market. The new Line Note will bear interest at a) LIBOR plus 2.75% or b) the lender’s prime rate, at Griffon’s option, through its expiration date on June 30, 2015. Upon expiration or at an earlier date, at Griffon’s option, the new Line Note will be combined with the Term Loan and require quarterly principal payments based on the remaining amortization schedule at a weighted average interest rate of the combined loans, with a balloon payment due at the final maturity date of December 31, 2018, based on the new amortization schedule. The new Line Note and the Term Loan are secured by shares purchased with the proceeds of the loan and with a lien on the assets of Griffon and its material domestic subsidiaries securing a limited amount of the loan (which lien ranks pari passu with the lien granted on such assets securing the debt under Griffon’s revolving credit facility; see footnote (a) above), and Griffon guarantees repayment.

[5] In October 2006, CBP entered into a capital lease totaling $14,290 for real estate in Troy, Ohio. 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. At June 30, 2014, $8,798 was outstanding.

[6] In November 2010, Clopay Europe GmbH (“Clopay Europe”) entered into a €10,000 revolving credit facility and a €20,000 term loan. The term loan was paid off in December 2013 and the revolver had borrowings of $4,093 at June 30, 2014. The revolving facility matures in November 2014, but is renewable upon mutual agreement with the bank. The revolving credit facility accrues interest at EURIBOR plus 2.20% per annum (2.41% at June 30, 2014). Clopay Europe is required to maintain a certain minimum equity to assets ratio and keep leverage below a certain level, defined as the ratio of total debt to EBITDA.Clopay do Brazil maintains lines of credit of approximately $5,700. Interest on borrowings accrues at a rate of Brazilian CDI plus 6.0% (16.80% at June 30, 2014). At June 30, 2014 there was $3,660 borrowed under the lines. Clopay Plastic Products Company, Inc. guarantees the loan and lines.In November 2012, Garant G.P. (“Garant”) entered into a CAD $15,000 revolving credit facility. The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum (1.46% LIBOR USD and 2.51% Bankers Acceptance Rate CDN as of June 30, 2014). The revolving facility matures in November 2015. Garant is required to maintain a certain minimum equity. At June 30, 2014, there were no borrowings under the revolving credit facility with CAD $15,000 available for borrowing.In December 2013 and May 2014, Northcote Holdings Pty Ltd entered into two term loans in the outstanding amounts of AUD $12,500 and AUD $20,000, respectively. The AUD $12,500 and AUD $20,000 term loans are unsecured and require quarterly interest payments, with quarterly principal payments of $625 beginning in August 2015 on the AUD $20,000 term loan. Remaining principal is due at maturity in December 2016 and May 2017, respectively. The loans accrue interest at Bank Bill Swap Bid Rate “BBSY” plus 2.8% per annum (5.5% at June 30, 2014 for each loan). As of June 30, 2014, Griffon had an outstanding combined balance of $30,612 on the term loans. Subsidiaries of Northcote Holdings Pty Ltd also maintain two lines of credit of AUD $3,000 and AUD $5,000 which accrue interest at BBSY plus 2.25% per annum (5.00% at June 30, 2014) and 2.50% per annum (5.25% at June 30, 2014), respectively. At June 30, 2014, there were no outstanding borrowings under the lines. Griffon Corporation guarantees the term loans and the AUD $3,000 line of credit; the assets of a subsidiary of Northcote Holdings Pty Ltd secures the AUD $5,000 line of credit.

[7] Other long-term debt primarily consists of capital leases.