Common Stock, Number of Shares Held by Shareholder

No definition available.

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- Definition

Maximum percentage of exercise price at grand date fair value.

+ References

No definition available.

+ Details

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- References

No definition available.

+ Details

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- Definition

Share based compensation arrangement by share based payment award equity instrument other than options additional grants in future.

+ References

No definition available.

+ Details

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Award Post-Vesting Holding Period

+ References

No definition available.

+ Details

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number of Persons Granted Shares

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of shares paid for employee tax withholding.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Shares paid for employee tax withholding.

+ References

No definition available.

+ Details

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Namespace Prefix:	gff_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The price per share of the common shares repurchased during the period.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Aggregate dividends paid during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

+ Details

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

+ Details

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

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Data Type:	num:perShareItemType
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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

+ Details

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Period Type:	duration

- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

+ Details

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

+ Details

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value, before forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

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- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

+ Details

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- Definition

Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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- Details

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SHAREHOLDERS' EQUITY (Details)			1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended	48 Months Ended	56 Months Ended
SHAREHOLDERS' EQUITY (Details)	May. 04, 2016 $ / shares	Jan. 29, 2016 USD ($)	Dec. 31, 2014 shares	Mar. 31, 2016 USD ($) senior_executive $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Mar. 31, 2015 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares shares	Mar. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 $ / shares	Jan. 29, 2020 shares	Mar. 31, 2016 USD ($) $ / shares shares	May. 31, 2014 USD ($)	Dec. 10, 2013 USD ($) shares
SHAREHOLDERS' EQUITY (Details) [Line Items]
Common stock, dividends, per share, cash paid (in Dollars per share) \| $ / shares				$ 0.05		$ 0.04	$ 0.1	$ 0.08	$ 0.16
Share-based compensation arrangement by share-based payment award, description							Options granted under the Incentive Plan may be either “incentive stock options” or nonqualified stock options, generally expire ten years after the date of grant and are granted at an exercise price of not less than 100% of the fair market value at the date of grant.
Share-based compensation arrangement by share-based payment award, expiration period							10 years
Maximum percentage of exercise price at grand date fair value							100.00%
Stock-based compensation \| $				$ 2,489,000		$ 2,795,000	$ 5,555,000	$ 5,372,000
Stock repurchase program, authorized amount \| $												$ 50,000,000	$ 50,000,000
Stock Repurchased During Period, Shares			4,444,444	1,516,919			1,949,338,000				14,256,115
Stock repurchased during period, value \| $				$ 22,705,000			$ 29,935,000				$ 183,067,000
Stock repurchased during period per share (in Dollars per share) \| $ / shares				$ 14.97			$ 15.36				$ 12.84
Stock repurchase program, remaining authorized repurchase amount \| $				$ 27,990,000			$ 27,990,000				$ 27,990,000
Shares paid for tax withholding for share based compensation (in Shares)				188,222	1,683
Shares paid for tax withholding for share based compensation, value \| $				$ 3,577,000	$ 25,000
Shares paid for tax withholding for share based compensation, value per share (in Dollars per share) \| $ / shares				$ 19.00	$ 14.85
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased													5,555,556,000
Incentive Plan [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Number of shares authorized for award (in Shares)				2,350,000			2,350,000				2,350,000
New shares issued (in Shares)				600,000
Incentive Stock Options [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Number of shares available for grant (in Shares)				1,795,603			1,795,603				1,795,603
2006 Equity Incentive Plan [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share based compensation arrangement by share based payment award equity instruments other than options additional grants in future (in Shares)				0			0				0
Performance Shares [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares)				31,761	372,243
Award vesting period				3 years	3 years
Equity instruments other than options, vested in period, fair value \| $				$ 473,000	$ 6,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value \| $ / shares				$ 14.90
Equity instruments other than options, grants in period, weighted average grant date fair value (in Dollars per share) \| $ / shares					$ 17.26
Restricted Stock and Performance Shares [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares)				677,461
Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Equity instruments other than options, grants in period (in Shares)				40,700
Award vesting period				3 years
Equity instruments other than options, vested in period, fair value \| $				$ 618,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value \| $ / shares				$ 15.18
Minimum [Member] \| Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Award vesting period							3 years
Maximum [Member] \| Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Award vesting period							4 years
Executive Officer [Member] \| Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value \| $ / shares				$ 7.02			$ 7.02				$ 7.02
Equity instruments other than options, grants in period (in Shares)				605,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Number of Persons Granted Shares \| senior_executive				2
Award vesting period				4 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Post-Vesting Holding Period				2 years
Stock Granted, Value, Share-based Compensation, Gross \| $		$ 4,247,000
Scenario, Forecast [Member] \| Executive Officer [Member] \| Minimum [Member] \| Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period										220,000
Scenario, Forecast [Member] \| Executive Officer [Member] \| Maximum [Member] \| Restricted Stock [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period										605,000
Subsequent Event [Member]
SHAREHOLDERS' EQUITY (Details) [Line Items]
Dividends declared, amount per share (in Dollars per share) \| $ / shares	$ 0.05