NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) In Thousands, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended	12 Months Ended					12 Months Ended				3 Months Ended			3 Months Ended		12 Months Ended	3 Months Ended	12 Months Ended				12 Months Ended			12 Months Ended								12 Months Ended								1 Months Ended	12 Months Ended																12 Months Ended		12 Months Ended						3 Months Ended	12 Months Ended									12 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Dec. 31, 2012	Sep. 30, 2013 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2007 USD ($)	Dec. 20, 2010 USD ($)	Sep. 30, 2012 Plastics [Member] Foreign Term Loan [Member]	Sep. 30, 2013 Letter Of Credit Subfacility [Member] Revolver Due 2018 [Member] USD ($)	Mar. 28, 2013 Letter Of Credit Subfacility [Member] Revolver Due 2018 [Member] USD ($)	Mar. 28, 2013 Multicurrency Subfacility [Member] Revolver Due 2018 [Member] USD ($)	Mar. 28, 2013 Swingline Subfacility [Member] Revolver Due 2018 [Member] USD ($)	Mar. 28, 2013 Margin Rate [Member] Revolver Due 2018 [Member]	Sep. 30, 2013 LIBOR Rate [Member] Foreign Line of Credit [Member]	Mar. 28, 2013 LIBOR Rate [Member]	Sep. 30, 2013 Bankers Acceptance Rate [Member] Foreign Line of Credit [Member]	Sep. 30, 2010 Employee Stock Ownership Plan Loan [Member] USD ($)	Sep. 30, 2013 Convertible Debt 2017 [Member] USD ($)	Sep. 30, 2013 Convertible Debt 2017 [Member] USD ($)	Sep. 30, 2012 Convertible Debt 2017 [Member] USD ($)	Sep. 30, 2010 Convertible Debt 2017 [Member]	Dec. 21, 2009 Convertible Debt 2017 [Member] USD ($)	Sep. 30, 2010 Employee Stock Ownership Plan Loan [Member]	Sep. 30, 2013 Employee Stock Ownership Plan Loan [Member] USD ($)	Aug. 31, 2010 Employee Stock Ownership Plan Loan [Member] USD ($)	Sep. 30, 2013 Capital Lease Obligations [Member] USD ($)		Sep. 30, 2012 Capital Lease Obligations [Member] USD ($)		Sep. 30, 2011 Capital Lease Obligations [Member]		Sep. 30, 2007 Capital Lease Obligations [Member] USD ($)	Sep. 30, 2011 Senior Notes [Member] USD ($)	Sep. 30, 2013 Real Estate Mortgages Loan [Member] USD ($)		Sep. 30, 2012 Real Estate Mortgages Loan [Member] USD ($)		Sep. 30, 2011 Real Estate Mortgages Loan [Member]		Oct. 21, 2013 Real Estate Mortgages Loan [Member] USD ($)	Sep. 30, 2013 Other Real Estate Mortgages Loan [Member]	Nov. 30, 2011 Employee Stock Ownership Plan Loan [Member] USD ($)	Sep. 30, 2013 Employee Stock Ownership Plan Loan [Member] USD ($)		Sep. 30, 2012 Employee Stock Ownership Plan Loan [Member] USD ($)		Sep. 30, 2011 Employee Stock Ownership Plan Loan [Member]		Sep. 30, 2010 Employee Stock Ownership Plan Loan [Member]	Sep. 30, 2009 Employee Stock Ownership Plan Loan [Member]	Sep. 30, 2013 Term Loan [Member]	Sep. 30, 2011 Term Loan [Member] EUR (€)	Sep. 30, 2013 Revolver Due 2013 [Member] USD ($)		Sep. 30, 2011 Revolver Due 2013 [Member] EUR (€)		Sep. 30, 2012 Revolver Due 2013 [Member] USD ($)		Sep. 30, 2012 Foreign Term Loan [Member] Brazilian CDI [Member]	Sep. 30, 2013 Foreign Term Loan [Member] Brazilian CDI [Member]	Sep. 30, 2013 Foreign Term Loan [Member] USD ($)		Sep. 30, 2012 Foreign Term Loan [Member] USD ($)		Sep. 30, 2011 Foreign Term Loan [Member]		Dec. 31, 2012 Foreign Line of Credit [Member] CAD	Sep. 30, 2013 Foreign Line of Credit [Member] USD ($)		Sep. 30, 2013 Foreign Line of Credit [Member] CAD		Sep. 30, 2012 Foreign Line of Credit [Member] USD ($)		Sep. 30, 2011 Foreign Line of Credit [Member]		Sep. 30, 2012 Convertible Debt 2023 [Member] USD ($)	Sep. 30, 2013 Term Loan 2016 [Member] USD ($)	Sep. 30, 2013 Asset Based Loan [Member] USD ($)	Sep. 30, 2011 Asset Based Loan [Member]		Mar. 28, 2013 Revolver Due 2016 [Member] USD ($)	Sep. 30, 2013 Revolver Due 2018 [Member] USD ($)	Mar. 28, 2013 Revolver Due 2018 [Member] USD ($)
NOTES PAYABLE, CAPITALIZED LEASES AND LONG-TERM DEBT (Details) [Line Items]
Capital Leases, Future Minimum Payments Due, Next Twelve Months				$ 1,579
Capital Leases, Future Minimum Payments Due in Two Years				1,550
Capital Leases, Future Minimum Payments Due in Three Years				1,511
Capital Leases, Future Minimum Payments Due in Four Years				1,437
Capital Leases, Future Minimum Payments Due in Five Years				1,425
Capital Leases, Future Minimum Payments Due Thereafter				4,470
Capital Leased Assets, Gross				15,304	15,342
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation				5,460	4,414
Deferred Interest Charges				207	232
Capitalized Leases Interest Rate Minimum				5.00%
Capitalized Leases Interest Rate Maximum				10.00%
Capitalized Leases Maturity Description				2014 through 2022
Amortization				1,605	1,598	1,663
Proceeds from Issuance of Long-term Debt				303	4,000	674,251																											14,290																															4,000														375,000	125,000
Payments to Acquire Buildings							10,000
Capital Lease Maturity Year							2022
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate							5.00%
Debt Agreements Future Minimum Payments Due, Next Twelve Months				10,768
Debt Agreements Future Minimum Payments Due In Two Years				6,488
Debt Agreements Future Minimum Payments Due In Three Years				17,863
Debt Agreements Future Minimum Payments Due In Four Years				112,048
Debt Agreements Future Minimum Payments Due In Five Years				551,207
Debt Agreements Future Minimum Payments Due Thereafter				4,127
Debt Instrument, Face Amount								11,834															100,000			20,000								550,000							17,175
Debt Instrument, Interest Rate, Stated Percentage				4.00%																			4.00%											7.125%								6.30%																																			4.00%
Number of Senior Secured Revolving Credit Facility				2
Line of Credit Facility, Current Borrowing Capacity											60,000	50,000																																																											15,000											200,000		225,000
Proceeds from Lines of Credit													30,000
Line of Credit Facility, Interest Rate During Period														1.00%		2.00%
Line of Credit Facility, Amount Outstanding				0						25,457																																																				4,600
Line of Credit Facility, Remaining Borrowing Capacity																																																																																			199,543
Debt Instrument, Convertible, Conversion Ratio																			67.8495
Debt Conversion, Converted Instrument, Amount																			1,000
Debt Instrument, Convertible, Conversion Price (in Dollars per share)																			$ 14.74	$ 14.74
Debt Instrument, Convertible, Terms of Conversion Feature																						1%
Last Conversion Price Adjustment (in Dollars per share)																			$ 0.075	$ 0.075
Potential Conversion Rate Adjustment																			0.66%	0.66%
Debt Instrument, Convertible, If-converted Value in Excess of Principal																				15,720	15,720
Debt Instrument, Maturity Date		Dec. 31, 2013		Feb. 29, 2016																															Oct. 31, 2018																	Nov. 30, 2016
Debt Instrument, Description of Variable Rate Basis																																			LIBOR plus 2.75%				The loans bear interest at a rate of LIBOR plus 3% with the option to swap to a fixed rate.											The loan bears interest at a) LIBOR plus 2.5% or b) the lender's prime rate, at Griffon's option.						The facility accrues interest at EURIBOR plus 2.45% per annum and the term loan accrues interest at EURIBOR plus 2.20% per annum.
Debt Instrument, Basis Spread on Variable Rate			1.30%			2.45%																													2.75%				3.00%											2.50%			2.20%
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition				1 year 146 days																				1 year
Share-based Compensation Arrangement by Share-based Payment Award, Shares Purchased for Award (in Shares)																		1,874,737
Stock Repurchased During Period, Value				26,285	10,379	12,367												19,973
Debt Instrument Exercised Period	5 years
Debt Instrument, Periodic Payment, Principal																																											250
Debt Instrument Balloon Payment																																											15,223
Long-term Debt, Gross				702,501	716,217																				17,973		9,529	[1]	10,455	[1]					13,212	[2]	14,063	[2]						21,098	[3]	22,723	[3]							0	[4]			0	[4]			411	[5]	2,693	[5]				4,606	[5]			2,064	[5]
Employee Stock Ownership Plan Debt Structure Required Quarterly Principal Payments																																												156
Employee Stock Ownership Plan Debt Structure Balance Of Loan For Interest																																												3,125
Stock Issued During Period, Shares, New Issues (in Shares)																																																			547,605
Employee Stock Ownership Plan (ESOP), Debt Structure, Employer Loan Guarantee																																												3,125
Proceeds from Long-term Lines of Credit (in Euro)																																																					20,000			10,000												15,000
Line of Credit Facility, Expiration Date				Nov. 30, 2013
Period of Installments for Term Loan					4	10
Debt Instrument, Interest Rate During Period				6.00%																							5.30%	[1]	5.30%	[1]	5.30%	[1]			4.90%	[2]	4.00%	[2]	5.60%	[2]				2.90%	[3]	3.00%	[3]	2.70%	[3]					0.50%	[4]	1.20%	[4]			104.50%		9.80%	[5]	10.50%	[5]		[5]		12.90%	[5]	12.90%	[5]	14.30%	[5]	3.00%	[5]				6.20%	[6]
Line of Credit Facility, Interest Rate Description																																																														9.10%						The facility accrues interest at LIBOR (USD) or the Bankers Acceptance Rate (CDN) plus 1.3% per annum
Percentage of Guaranty by Segment									50.00%
Maintains Maximum Amount Of Line Of Credit																																																														4,950
Line of Credit Facility, Interest Rate at Period End															1.48%		2.46%																																												15.23%
Proceeds from Long-term Lines of Credit (in Dollars)																																																					20,000			10,000												15,000
Convertible Subordinated Debt																																																																													532
Derivative, Notional Amount																																																																														200,000
Derivative, Fixed Interest Rate																																																																														2.085%
Gains (Losses) on Extinguishment of Debt						(26,164)
Deferred Financing Charges And Original Issuer Discounts						21,617
Premium On Term Loan						3,703
Swap And Other Breakage Costs						$ 844

[1] 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.

[2] On December 20, 2010, Griffon entered into two second lien real estate mortgages to secure new loans totaling $11,834. The loans mature in February 2016, are collateralized by the related properties and are guaranteed by Griffon. The loans bear interest at a rate of LIBOR plus 3% with the option to swap to a fixed rate. On October 21, 2013, Griffon refinanced these real estate mortgages with total principal of $17,175, maturing in October 2018 and bearing interest at LIBOR plus 2.75%.Griffon has other real estate mortgages, collateralized by real property, which bear interest at 6.3% and mature in 2016.

[3] Griffon's Employee Stock Ownership Plan ("ESOP") entered into a loan agreement in August 2010 to borrow $20,000 over a one-year period. The proceeds were used to purchase 1,874,737 shares of Griffon common stock in the open market for $19,973. The loan bears interest at a) LIBOR plus 2.5% or b) the lender's prime rate, at Griffon's option. In November 2011, Griffon exercised an option to convert the outstanding loan to a five-year term loan; principal is payable in quarterly installments of $250, beginning December 2011, with a balloon payment of $15,223 due at maturity (November 2016). The loan is secured by shares purchased with the proceeds of the loan, and repayment is guaranteed by Griffon. At September 30, 2013, $17,973 was outstanding.In addition, the ESOP is party to a loan agreement which requires quarterly principal payments of $156 and interest through the extended expiration date of December 2013, at which time the $3,125 balance of the loan, and any outstanding interest, will be payable. Griffon has the intent and ability to refinance the December 2013 balance and has classified the balance in Long-Term Debt. The primary purpose of this loan was to purchase 547,605 shares of Griffon's common stock in October 2008. The loan is secured by shares purchased with the proceeds of the loan and repayment is guaranteed by Griffon. The loan bears interest at rates based upon the prime rate or LIBOR. At September 30, 2013, $3,125 was outstanding and classified as long-term debt as the Company has the intent and ability to refinance in 2014.

[4] In November 2010, Clopay Europe GMBH ("Clopay Europe") entered into a 10,000 revolving credit facility and a 20,000 term loan. The facility accrues interest at EURIBOR plus 2.45% per annum and the term loan accrues interest at EURIBOR plus 2.20% per annum. The revolving facility matures in November 2013, but is renewable upon mutual agreement with the bank. In July 2011, the full 20,000 was drawn on the term loan, with a portion of the proceeds used to repay borrowings under the revolving credit facility. The term loan is payable in ten equal quarterly installments which began in September 2011, with maturity in December 2013. Under the term loan, 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.

[5] In February 2012, Clopay do Brazil, a subsidiary of Plastics, borrowed $4,000 at a rate of 104.5% of Brazilian CDI (9.10% at September 30, 2013). The loan was used to refinance existing loans, is collateralized by accounts receivable and a 50% guaranty by Plastics and is to be repaid in four equal, semi-annual installments of principal plus accrued interest beginning in August 2012. Clopay do Brazil also maintains lines of credit of approximately $4,950. Interest on borrowings accrue at a rate of Brazilian CDI plus 6.0% (15.23% at September 30, 2013). At September 30, 2013 there was approximately $4,600 borrowed under the 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 (1.48% LIBOR USD and 2.46% Bankers Acceptance Rate CDN as of September 30, 2013). The revolving facility matures in November 2015. Garant is required to maintain a certain minimum equity. At September 30, 2013, there were 0 borrowings under the revolving credit facility with CAD $15,000 available for borrowing

[6] In connection with the ATT acquisition, Clopay Ames True Temper Holding Corp. ("Clopay Ames"), a subsidiary of Griffon, entered into a $375,000 secured term Loan ("Term Loan") and a $125,000 asset based lending agreement ("ABL").On November 30, 2010, Clopay Ames, as required under the Term Loan agreement, entered into an interest rate swap on a notional amount of $200,000 of the Term Loan. The agreement fixed the LIBOR component of the Term Loan interest rate at 2.085% for the notional amount of the swap.On March 17, 2011, the Term Loan and swap were terminated, and on March 18, 2011, the ABL was terminated, in connection with the issuance of the Senior Notes and Credit Agreement.