LONG-TERM DEBT (Details)	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended						9 Months Ended	12 Months Ended		9 Months Ended				9 Months Ended		3 Months Ended				9 Months Ended							3 Months Ended				9 Months Ended						9 Months Ended	3 Months Ended				9 Months Ended						3 Months Ended				9 Months Ended						1 Months Ended		3 Months Ended		12 Months Ended			9 Months Ended	1 Months Ended		3 Months Ended				9 Months Ended				12 Months Ended			12 Months Ended	3 Months Ended				9 Months Ended						3 Months Ended						9 Months Ended						1 Months Ended		1 Months Ended				3 Months Ended				9 Months Ended
	Dec. 31, 2013 USD ($) loan	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)	Dec. 31, 2012	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2007	Oct. 21, 2013 USD ($) property	Sep. 30, 2013 USD ($)	Jun. 30, 2014 Northcote Holdings Pty. Ltd [Member] USD ($) line_of_credit	May 31, 2014 Northcote Holdings Pty. Ltd [Member] loan	Jun. 30, 2014 Convert. debt due 2017 [Member] USD ($)	Sep. 30, 2010 Convert. debt due 2017 [Member]	Dec. 21, 2009 Convert. debt due 2017 [Member] USD ($)	Jun. 30, 2014 LIBOR Rate [Member]	Jun. 30, 2014 Revolver due 2019 [Member] USD ($)	Feb. 14, 2014 Revolver due 2019 [Member] Letter Of Credit Subfacility [Member] USD ($)	Feb. 14, 2014 Revolver due 2019 [Member] Multicurrency Subfacility [Member] USD ($)	Jun. 30, 2014 Revolver due 2019 [Member] Swingline Subfacility [Member] USD ($)	Jun. 30, 2014 Revolver due 2019 [Member] Margin Rate [Member]	Jun. 30, 2014 Senior notes due 2022 [Member] USD ($)		Jun. 30, 2013 Senior notes due 2022 [Member] USD ($)		Jun. 30, 2014 Senior notes due 2022 [Member] USD ($)		Jun. 30, 2013 Senior notes due 2022 [Member] USD ($)		Feb. 27, 2014 Senior notes due 2022 [Member] USD ($)	Sep. 30, 2013 Senior notes due 2022 [Member] USD ($)		Jun. 30, 2014 Senior notes due 2018 [Member] USD ($)		Jun. 30, 2013 Senior notes due 2018 [Member] USD ($)		Jun. 30, 2014 Senior notes due 2018 [Member] USD ($)		Jun. 30, 2013 Senior notes due 2018 [Member] USD ($)		Sep. 30, 2013 Senior notes due 2018 [Member] USD ($)		Jun. 30, 2014 Senior Notes [Member] USD ($)	Jun. 30, 2014 Real estate mortgages [Member] USD ($)		Jun. 30, 2013 Real estate mortgages [Member] USD ($)		Jun. 30, 2014 Real estate mortgages [Member] USD ($)		Jun. 30, 2013 Real estate mortgages [Member] USD ($)		Sep. 30, 2013 Real estate mortgages [Member] USD ($)		Jun. 30, 2014 ESOP Loans [Member] USD ($)		Jun. 30, 2013 ESOP Loans [Member] USD ($)		Jun. 30, 2014 ESOP Loans [Member] USD ($)		Jun. 30, 2013 ESOP Loans [Member] USD ($)		Sep. 30, 2013 ESOP Loans [Member] USD ($)		Jul. 31, 2014 ESOP Loan July 2014 [Member] Subsequent Event [Member] USD ($)	Jul. 31, 2014 ESOP Loan July 2014 [Member] Subsequent Event [Member] London Interbank Offered Rate (LIBOR) [Member]	Dec. 31, 2013 Term Loan December 2013 and May 2014 [Member] Northcote Holdings Pty. Ltd [Member]	Jun. 30, 2014 Term Loan December 2013 and May 2014 [Member] Northcote Holdings Pty. Ltd [Member] USD ($)	Sep. 30, 2011 Term Loan [Member] EUR (€)	Jun. 30, 2014 Term Loan [Member]	Dec. 31, 2013 Term Loan [Member] Northcote Holdings Pty. Ltd [Member] AUD	Jun. 30, 2014 Term Loan [Member] Brazilian CDI [Member]	May 31, 2014 Term Loan May 2014 [Member] Northcote Holdings Pty. Ltd [Member] USD ($)	May 31, 2014 Term Loan May 2014 [Member] Northcote Holdings Pty. Ltd [Member] AUD	Jun. 30, 2014 Capital lease - real estate [Member] USD ($)		Jun. 30, 2013 Capital lease - real estate [Member] USD ($)		Jun. 30, 2014 Capital lease - real estate [Member] USD ($)		Jun. 30, 2013 Capital lease - real estate [Member] USD ($)		Sep. 30, 2007 Capital lease - real estate [Member] USD ($)	Sep. 30, 2013 Capital lease - real estate [Member] USD ($)		Sep. 30, 2011 Revolver Due 2013 [Member] EUR (€)	Jun. 30, 2014 Non U.S. term loans [Member] USD ($)		Jun. 30, 2013 Non U.S. term loans [Member] USD ($)		Jun. 30, 2014 Non U.S. term loans [Member] USD ($)		Jun. 30, 2013 Non U.S. term loans [Member] USD ($)		Sep. 30, 2013 Non U.S. term loans [Member] USD ($)		Jun. 30, 2014 Non U.S. lines of credit [Member] USD ($)		Jun. 30, 2014 Non U.S. lines of credit [Member] CAD	Jun. 30, 2013 Non U.S. lines of credit [Member] USD ($)		Dec. 31, 2012 Non U.S. lines of credit [Member] CAD	Jun. 30, 2014 Non U.S. lines of credit [Member] USD ($)		Jun. 30, 2013 Non U.S. lines of credit [Member] USD ($)		Sep. 30, 2013 Non U.S. lines of credit [Member] USD ($)		Dec. 31, 2013 Non U.S. lines of credit [Member] Line of Credit One [Member] Northcote Holdings Pty. Ltd [Member]	Jun. 30, 2014 Non U.S. lines of credit [Member] Line of Credit One [Member] Northcote Holdings Pty. Ltd [Member] USD ($)	May 31, 2014 Non U.S. lines of credit [Member] Line of Credit Two [Member] Northcote Holdings Pty. Ltd [Member]	Jun. 30, 2014 Non U.S. lines of credit [Member] Line of Credit Two [Member] Northcote Holdings Pty. Ltd [Member] USD ($)	Jun. 30, 2014 Non U.S. lines of credit [Member] LIBOR Rate [Member]	Jun. 30, 2014 Non U.S. lines of credit [Member] Bankers Acceptance Rate [Member]	Jun. 30, 2014 Revolver due 2019 [Member] USD ($)		Jun. 30, 2013 Revolver due 2019 [Member] USD ($)		Jun. 30, 2014 Revolver due 2019 [Member] USD ($)		Jun. 30, 2013 Revolver due 2019 [Member] USD ($)		Feb. 14, 2014 Revolver due 2019 [Member] USD ($)	Sep. 30, 2013 Revolver due 2019 [Member] USD ($)
Debt Instrument [Line Items]
Face amount	$ 21,098,000								$ 17,175,000						$ 100,000,000															$ 600,000,000			$ 550,000,000				$ 550,000,000																																	12,500,000			20,000,000
Debt instrument, interest rate, stated percentage															4.00%															5.25%			7.125%				7.125%
Payment of tender offer premium					31,530,000
Interest paid		10,060,000	11,730,000		32,395,000	34,795,000																7,875,000	[1]	0	[1]	10,675,000	[1]	0	[1]				0	[1]	9,797,000	[1]	15,930,000	[1]	29,391,000	[1]			16,716,000	124,000	[2]	133,000	[2]	376,000	[2]	407,000	[2]			192,000	[3]	151,000	[3]	524,000	[3]	476,000	[3]													112,000	[4]	125,000	[4]	345,000	[4]	381,000	[4]					273,000	[5]	109,000	[5]	426,000	[5]	415,000	[5]			307,000	[5]		155,000	[5]		724,000	[5]	415,000	[5]									309,000	[1]	179,000	[1]	782,000	[1]	603,000	[1]
Underwriting fees and other expense capitalized					9,950,000
Gains (losses) on extinguishment of debt		0	0		(38,890,000)	0																											(38,890,000)
Write off of deferred debt issuance cost					6,574,000
Prepaid interest on defeased note on extinguishment of debt					786,000
Line of credit facility, current borrowing capacity																		60,000,000	50,000,000																																																																																										3,000,000		5,000,000											225,000,000
Proceeds from lines of credit																				30,000,000
Line of credit facility, interest rate during period																2.25%					1.25%
Maximum percentage of equity interest of subsidiaries borrowings guaranteed					65.00%
Line of credit facility, amount outstanding		20,365,000			20,365,000		4,093,000				0						25,000,000																																																		30,612,000																			3,660,000				3,660,000						0						0
Line of credit facility, remaining borrowing capacity																	179,635,000
Debt instrument, convertible, conversion ratio													68.6238
Debt conversion, converted instrument, amount													1,000,000
Debt instrument, convertible, conversion price (in Dollars per share)													$ 14.53
Debt instrument, convertible, terms of conversion feature														1.00%
Debt instrument, convertible, conversion price adjustment													$ 0.03
Debt instrument, convertible, conversion ratio adjustment													27.00%
Debt instrument, convertible, if-converted value in excess of principal													15,720,000
Number of properties refinanced									2
Debt instrument, description of variable rate basis							The revolving credit facility accrues interest at EURIBOR plus 2.20% per annum (2.41% at June 30, 2014).																																									The loans bear interest at a rate of LIBOR plus 2.75%										The loan bears interest at a) LIBOR plus 2.25% or b) the lender’s prime rate, at Griffon’s option.
Debt instrument, basis spread on variable rate				1.30%	2.20%																																											2.75%										2.25%							2.75%	2.80%																																										2.25%		2.50%
Long-term debt, gross		819,598,000			819,598,000					702,501,000												600,000,000	[1]			600,000,000	[1]				0	[1]	0	[1]			0	[1]			550,000,000	[1]		16,603,000	[2]			16,603,000	[2]			13,212,000	[2]	29,583,000	[3]			29,583,000	[3]			21,098,000	[3]											8,798,000	[4]			8,798,000	[4]				9,529,000	[4]		30,612,000	[5]			30,612,000	[5]			3,115,000	[5]	7,754,000	[5]					7,754,000	[5]			4,606,000	[5]							25,000,000	[1]			25,000,000	[1]				0	[1]
Number of refinanced ESOP loan	2
Number of new term loan refinance from esop loans	1
Amount of line note available to purchase common stock in open market	10,000,000																																																															10,000,000
Shares purchased for award (in Shares)					749,977
Shares purchased for award value					10,000,000
Debt instrument, periodic payment, principal					419,000																																																					505,000														625,000
Debt instrument balloon payment																																																										22,400,000
Proceeds from issuance of long-term debt					682,913,000	303,000																																																																												14,290,000
Capital lease maturity year								2022
Long-term debt, percentage bearing fixed interest, percentage rate								5.00%
Proceeds from long-term lines of credit																																																																				20,000,000																	10,000,000													15,000,000			15,000,000
Debt instrument, number of loans											2	2
Maintains maximum amount of line of credit																																																																																						$ 5,700,000				$ 5,700,000
Debt instrument, interest rate during period					6.00%																	5.50%	[1]			5.50%	[1]								7.40%	[1]	7.40%	[1]	7.40%	[1]				3.80%	[2]	4.90%	[2]	4.00%	[2]	4.90%	[2]			2.90%	[3]	2.80%	[3]	3.20%	[3]	2.90%	[3]										16.80%			5.30%	[4]	5.30%	[4]	5.40%	[4]	5.30%	[4]
Line of credit facility, interest rate at period end																																																																																																																1.46%	2.51%
Debt instrument, interest rate at period end																						5.25%	[1]			5.25%	[1]														7.10%	[1]																									5.50%		2.41%					5.00%	[4]			5.00%	[4]				5.00%	[4]
Debt instrument, interest rate, effective percentage																																																																																																													5.00%		5.25%

[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 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.

[3] 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.

[4] 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.

[5] 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.