EMPLOYEE BENEFIT PLANS (Tables)

12 Months Ended

Sep. 30, 2013

Disclosure Text Block Supplement [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

Net periodic costs (benefits) were as follows:

	Defined Benefits for the Years Ended  September 30,									Supplemental Benefits for the Years  Ended September 30,
	2013			2012			2011			2013		2012		2011
Net periodic (benefits) costs:
Service cost	$	165		$	238		$	377		$	35	$	36	$	34
Interest cost		7,977			9,191			9,552			1,344		1,692		1,759
Expected return on plan assets		(11,870	)		(11,896	)		(11,501	)		—		—		—
Recognition of settlement		2,143			—			—			—		—		—
Amortization of:
Prior service costs		6			6			8			14		171		328
Actuarial loss		1,795			1,735			1,144			1,288		1,137		1,141
Total net periodic (benefits) costs	$	216		$	(726	)	$	(420	)	$	2,681	$	3,036	$	3,262

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,
	2013			2012			2011			2013			2012			2011
Discount rate		3.67	%		4.44	%		4.89	%		3.40	%		4.30	%		4.26	%
Average wage increase		0.11	%		0.11	%		0.72	%		4.87	%		4.89	%		4.89	%
Expected return on assets		7.80	%		7.71	%		7.72	%		—			—			—

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,
	2013			2012			2013			2012
Change in benefit obligation:
Benefit obligation at beginning of fiscal year	$	232,939		$	212,660		$	41,473		$	41,285
Benefits earned during the year		165			238			35			36
Interest cost		7,977			9,191			1,344			1,692
Plan participant contributions		15			16			—			—
Benefits paid		(10,632	)		(10,369	)		(4,051	)		(3,936	)
Benefits paid - settlement		(11,548	)		—			—			—
Effect of foreign currency		462			(413	)		—			—
Actuarial (gain) loss		(19,945	)		21,616			(127	)		2,396
Actuarial gain - settlement		(3,472	)		—			—			—
Benefit obligation at end of fiscal year		195,961			232,939			38,674			41,473
Change in plan assets:
Fair value of plan assets at beginning of fiscal year		160,823			137,678			—			—
Actual return on plan assets		12,537			25,190			—			—
Plan participant contributions		15			16			—			—
Company contributions		2,203			8,638			4,051			3,936
Effect of foreign currency		333			(330	)		—			—
Benefits paid		(10,632	)		(10,369	)		(4,051	)		(3,936	)
Benefits paid - settlement		(11,548	)		—			—			—
Fair value of plan assets at end of fiscal year		153,731			160,823			—			—
Projected benefit obligation in excess of plan assets	$	(42,230	)	$	(72,116	)	$	(38,674	)	$	(41,473	)
Amounts recognized in the statement of financial position consist of:
Accrued liabilities	$	—		$	—		$	(4,031	)	$	(3,897	)
Other liabilities (long-term)		(42,230	)		(72,116	)		(34,643	)		(37,576	)
Total Liabilities		(42,230	)		(72,116	)		(38,674	)		(41,473	)
Net actuarial losses		16,679			44,656			19,335			20,750
Prior service cost		4			10			99			113
Deferred taxes		(5,839	)		(15,633	)		(6,802	)		(7,302	)
Total Accumulated other comprehensive loss, net of tax		10,844			29,033			12,632			13,561
Net amount recognized at September 30,	$	(31,386	)	$	(43,083	)	$	(26,042	)	$	(27,912	)
Accumulated benefit obligations	$	195,590		$	232,574		$	38,674		$	41,473
Information for plans with accumulated benefit obligations in excess of plan assets:
ABO	$	195,590		$	232,574		$	38,674		$	41,473
PBO		195,961			232,939			38,674			41,473
Fair value of plan assets		153,731			160,823			—			—

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,
	2013			2012			2013			2012
Weighted average discount rate		4.49	%		3.67	%		4.09	%		3.40	%
Weighted average wage increase		0.15	%		0.11	%		0.00	%		4.87	%

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

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

	At September 30,
	2013			2012			Target
Equity securities		55.8	%		66.0	%		63.0	%
Fixed income		41.3	%		29.0	%		37.0	%
Other		2.9	%		5.0	%		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 30,		Defined Benefits		Supplemental Benefits
	2014	$	10,794	$	4,085
	2015		10,866		4,010
	2016		11,049		3,954
	2017		11,192		3,895
	2018		11,322		3,453
	2019 through 2023		59,464		14,632

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:

At September 30, 2013	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	$	—	$	—	$	—	$	—
Short-term investment funds		—		2,949		—		2,949
Government agency securities		3,006		—		—		3,006
Debt instruments		30,856		—		—		30,856
Equity securities		47,690		—		—		47,690
Commingled funds		—		66,130		—		66,130
Limited partnerships and hedge fund investments		—		3,101		—		3,101
Total	$	81,552	$	72,180	$	—	$	153,732

At September 30, 2012	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		—		56,329		—		56,329
Insurance contracts		—		—		—		—
Limited partnerships and hedge fund investments		—		—		3,016		3,016
Total	$	62,742	$	95,075	$	3,016	$	160,833

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, 2012	$	3,016
Transfers out of Level 3		(3,016	)
Ending Balance At September 30, 2013	$	—

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

The ESOP shares were as follows:

	At September 30,
	2013		2012
Allocated shares		2,309,812		2,335,040
Unallocated shares		1,934,338		2,135,287
		4,244,150		4,470,327