EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Sep. 30, 2012

Schedule of Net Benefit Costs [Table Text Block]

Net periodic benefit costs (benefits) were as follows:

	Defined Benefits for the Years Ended September 30,									Supplemental Benefits for the Years Ended September 30,
	2012			2011			2010			2012		2011		2010
Net periodic costs (benefits)
Service cost	$	238		$	377		$	529		$	36	$	34	$	29
Interest cost		9,191			9,552			1,645			1,692		1,759		1,984
Expected return on plan assets		(11,896	)		(11,501	)		(1,371	)		—		—		—
Amortization of:
Prior service costs		6			8			9			171		328		328
Actuarial loss		1,735			1,144			1,064			1,137		1,141		986
Total net periodic costs (benefits)	$	(726	)	$	(420	)	$	1,876		$	3,036	$	3,262	$	3,327

Schedule of Assumptions Used [Table Text Block]

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,
	2012			2011			2010			2012			2011			2010
Discount rate		4.44	%		4.89	%		5.60	%		4.30	%		4.26	%		5.00	%
Average wage increase		0.11	%		0.72	%		3.50	%		4.89	%		4.89	%		5.00	%
Expected return on assets		7.71	%		7.72	%		7.00	%		—			—			—

Schedule Of Plan Assets And Benefit Obligation Of Defined Benefit Plan [Table Text Block]

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,
	2012			2011			2012			2011
Change in benefit obligation
Benefit obligation at beginning of fiscal year	$	212,660		$	200,208		$	41,285		$	43,220
Benefits earned during the year		238			378			36			34
Interest cost		9,191			9,552			1,692			1,759
Plan participant contributions		16			25			—			—
Benefits paid		(10,359	)		(10,607	)		(3,936	)		(3,915	)
Effect of foreign currency		(413	)		13			—			—
Actuarial loss		21,616			13,091			2,396			187
Benefit obligation at end of fiscal year		232,949			212,660			41,473			41,285
Change in Plan Assets
Fair value of plan assets at beginning of fiscal year		137,678			133,733			—			—
Actual return on plan assets		25,190			636			—			—
Plan participant contributions		16			25			—			—
Company contributions		8,638			13,889			3,936			3,915
Effect of foreign currency		(330	)		2			—			—
Benefits paid		(10,359	)		(10,607	)		(3,936	)		(3,915	)
Fair value of plan assets at end of fiscal year		160,833			137,678			—			—
Projected benefit obligation in excess of plan assets	$	(72,116	)	$	(74,982	)	$	(41,473	)	$	(41,285	)
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	$	—		$	—		$	(3,897	)	$	(3,918	)
Other liabilities (long-term)		(72,116	)		(74,982	)		(37,576	)		(37,367	)
Total Liabilites		(72,116	)		(74,982	)		(41,473	)		(41,285	)
Net actuarial losses		44,656			38,057			20,750			19,491
Prior service cost		10			16			113			284
Deferred taxes		(15,633	)		(13,326	)		(7,302	)		(6,921	)
Total Accumulated other comprehensive loss, net of tax		29,033			24,747			13,561			12,854
Net amount recognized at September 30,	$	(43,083	)	$	(50,235	)	$	(27,912	)	$	(28,431	)
Accumulated benefit obligations	$	232,574		$	212,430		$	41,473		$	40,878
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	$	232,574		$	212,430		$	41,473		$	40,878
PBO		232,949			212,660			41,473			41,285
Fair value of plan assets		160,833			137,678			—			—

Schedule Of Weighted Average Assumptions Used in Defined And Supplemental Benefit Obligations [Table Text Block]

The weighted-average assumptions used in determining the benefit obligations were as follows:

	Defined Benefits at September 30,						Supplemental Benefits at September 30,
	2012			2011			2012			2011
Weighted average discount rate		3.67	%		4.44	%		3.40	%		4.30	%
Weighted average wage increase		0.11	%		0.11	%		4.87	%		4.89	%

Schedule Of Actual And Weighted Average Assets Allocationfor Qualified Benefit plans [Table Text Block]

The actual and weighted-average asset allocation for qualified benefit plans were as follows:

	At September 30,
	2012			2011			Target
Equity securities		66.0	%		55.0	%		63.0	%
Fixed income		29.0	%		41.0	%		37.0	%
Other		5.0	%		4.0	%		0.0	%
Total		100.0	%		100.0	%		100.0	%

Schedule of Expected Benefit Payments [Table Text Block]

Estimated future benefit payments to retirees, which reflect expected future service, are as follows:

For the fiscal years ending September	Defined Benefits		Supplemental Benefits
2013	$	10,455	$	3,951
2014		10,789		3,951
2015		10,965		3,832
2016		11,208		3,778
2017		11,410		3,720
2018 through 2022		61,319		14,680

Schedule Of Fair Value Of Pension And Post Retirement Plan Assets By Asset Category [Table Text Block]

The following table presents the fair values of Griffon’s pension and post-retirement plan assets by asset category:

	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	$	29	$	—	$	—	$	29
Short-term investment funds		—		5,231		—		5,231
Government agency securities		—		2,899		—		2,899
Debt instruments		—		30,616		—		30,616
Equity securities		62,713		—		—		62,713
Commingled funds		—		50,105		6,224		56,329
Limited partnerships and hedge
fund investments		—		—		3,016		3,016
Total	$	62,742	$	88,851	$	9,240	$	160,833

	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Short-term investment funds	$	—	$	667	$	—	$	667
Government agency securities		382		2,741		—		3,123
Debt instruments		—		14,876		—		14,876
Equity securities		68,313		3,841		—		72,154
Commingled funds		—		46,858		—		46,858
Total	$	68,695	$	68,983	$	—	$	137,678

Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]

The activity for the level 3 assets was as follows:

Beginning Balance at September 30, 2011	$	—
Actual Return on Plan Assets		175
Purchases		9,065
Ending Balance at September 30, 2012	$	9,240

Schedule of Employee Stock Ownership Plan (ESOP) Disclosures [Table Text Block]

The ESOP shares were as follows:

	At September 30,
	2012		2011
Allocated shares		2,335,040		2,233,950
Unallocated shares		2,135,287		2,339,813
		4,470,327		4,573,763