XML 70 R57.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Debt - Additional Information (Detail) - USD ($) |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Mar. 24, 2014 | Mar. 31, 2016 | Dec. 02, 2015 | Mar. 31, 2015
Debt Instrument [Line Items] |  |  |  |
Short-term borrowings outstanding |  | $ 0 |  | $ 0
Letters of credit outstanding amount |  | 11,982,000 |  | $ 10,903,000
Long-term debt payment requirements over the next five years |  | 0 |  |
Letter of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit | $ 5,000,000 |  |  |
Letters of credit outstanding amount |  | $ 1,921,000 |  |
Revolving Credit Facility [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt Instrument, Covenant Compliance |  | The Company was in compliance with all such provisions as of and for the year ended March 31, 2016 |  |
Assets book value |  | $ 104,059,000 |  |
Revolving Credit Facility [Member] | Letter of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Availability under the line of credit |  | $ 3,079,000 |  |
Maximum funded debt to EBITDA ratio | 350.00% |  |  |
Annual facility fees | 0.375% |  |  |
Minimum earnings to interest ratio | 400.00% |  |  |
Revolving Credit Facility [Member] | Maximum [Member] | Letter of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Fee for outstanding letters of credit | 1.25% |  |  |
Revolving Credit Facility [Member] | Minimum [Member] | Letter of Credit [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Fee for outstanding letters of credit | 0.75% |  |  |
Revolving Credit Facility [Member] | Prime Rate [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Bank's prime rate |  | 3.50% |  | 3.25%
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Line of credit |  |  | $ 25,000,000 |
Maximum limit of credit facility |  |  | $ 50,000,000 |
Term period of agreement |  | 5 years |  |
Interest rate description |  | interest at either: (i) a rate equal to the bank’s prime rate; or (ii) a rate equal to LIBOR plus a margin |  |
Fix rate to reduce fee on outstanding |  | 0.40% |  |
Letters of credit outstanding amount |  | $ 1,749,000 |  |
Availability under the line of credit |  | $ 23,251,000 |  |
Debt instrument, covenant description |  | Under the new revolving credit facility, the Company covenants to maintain a maximum funded debt to EBITDA ratio, as defined in such credit facility, of 3.5 to 1.0 and a minimum earnings before interest expense and income taxes (“EBIT") to interest ratio, as defined in such credit facility, of 4.0 to 1.0. The agreement also provides that the Company is permitted to pay dividends without limitation if it maintains a maximum funded debt to EBITDA ratio equal to or less than 2.0 to 1.0 and permits the Company to pay dividends in an amount equal to 25% of net income if it maintains a funded debt to EBITDA ratio of greater than 2.0 to 1.0. |  |
Percentage of net income to be paid as dividend if EBITDA ratio is greater than 2.0 to 1 |  | 25.00% |  |
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] | Maximum [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Unused commitment fee for borrowing |  | 0.30% |  |
Fee for outstanding letters of credit |  | 1.20% |  |
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] | Maximum [Member] | Dividend Payment Covenant [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Maximum funded debt to EBITDA ratio |  | 200.00% |  |
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] | Minimum [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Unused commitment fee for borrowing |  | 0.20% |  |
Fee for outstanding letters of credit |  | 0.70% |  |
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, basis spread on variable rate |  | 1.75% |  |
Revolving Credit Facility [Member] | 2015 Credit Facility Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Debt instrument, basis spread on variable rate |  | 0.95% |  |
Bank of America, N.A. [Member] | 2015 Credit Facility Agreement [Member] |  |  |  |
Debt Instrument [Line Items] |  |  |  |
Letters of credit outstanding amount |  | $ 8,312,000 |  |

X
- Definition Debt Covenants Dividend Restriction as Percentage of Consolidated Net Income + References No definition available. + Details
Name: | ghm_DebtCovenantsDividendRestrictionAsPercentageOfConsolidatedNetIncome
Namespace Prefix: | ghm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The fixed rate fee for outstanding letters of credit that are secured by cash and cash equivalents. + References No definition available. + Details
Name: | ghm_FixedRateFeeForSecuredLettersOfCredit
Namespace Prefix: | ghm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The fee, expressed as a percentage of the standby letter of credit amount, incurred for the issuance of a standby letter of credit. + References No definition available. + Details
Name: | ghm_LetterOfCreditCommitmentFeePercentage
Namespace Prefix: | ghm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum funded debt to earnings before interest taxes depreciation and amortization ratio. + References No definition available. + Details
Name: | ghm_MaximumFundedDebtToEarningsBeforeInterestTaxesDepreciationAndAmortizationRatio
Namespace Prefix: | ghm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum earnings before interest expense and income taxes to interest ratio. + References No definition available. + Details
Name: | ghm_MinimumEarningsBeforeInterestExpenseAndIncomeTaxesToInterestRatio
Namespace Prefix: | ghm_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of assets pledged to secure a debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 + Details
Name: | us-gaap_DebtInstrumentCollateralAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition States whether the entity was in compliance with the debt covenants throughout the reporting period, and describes facts and circumstances of any compliance failure. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 + Details
Name: | us-gaap_DebtInstrumentCovenantCompliance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 + Details
Name: | us-gaap_DebtInstrumentCovenantDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used. + References No definition available. + Details
Name: | us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of the interest rate for the amounts borrowed under the credit facility, including the terms and the method for determining the interest rate (for example, fixed or variable, LIBOR plus a percentage, increasing rate, timing of interest rate resets, remarketing provisions). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityInterestRateDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility. + References No definition available. + Details
Name: | us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.13) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.(a),16(a)(1)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 + Details
Name: | us-gaap_ShortTermBorrowings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_ShortTermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_PrimeRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=ghm_DebtInstrumentOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=us-gaap_DividendPaidMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=ghm_BankOfAmericaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |