XML 28 R89.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended
--- | ---
Mar. 31, 2015 | Mar. 31, 2014 | Mar. 31, 2013
Reserve for Doubtful Accounts Receivable [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | $ 46 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | $ 33 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | $ 43 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember
Charged to Costs and Expenses | 24 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | 19 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | (10)us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember
Charged to Other Accounts | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember
Deductions | (8)us-gaap_ValuationAllowancesAndReservesDeductions / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | (6)us-gaap_ValuationAllowancesAndReservesDeductions / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember |
Balance at End of Period | 62 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | 46 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember | 33 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_AllowanceForDoubtfulAccountsMember
Product Warranty Liability [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | 308 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 408 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 215 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember
Charged to Costs and Expenses | 930 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 125 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 360 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember
Charged to Other Accounts | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember
Deductions | (585)us-gaap_ValuationAllowancesAndReservesDeductions / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | (225)us-gaap_ValuationAllowancesAndReservesDeductions / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | (167)us-gaap_ValuationAllowancesAndReservesDeductions / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember
Balance at End of Period | 653 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 308 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember | 408 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = us-gaap_WarrantyReservesMember
Restructuring Reserve [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Charged to Costs and Expenses | 1,718 us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense / us-gaap_ValuationAllowancesAndReservesTypeAxis = ghm_RestructuringReserveMember |  |
Charged to Other Accounts | 0 us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts / us-gaap_ValuationAllowancesAndReservesTypeAxis = ghm_RestructuringReserveMember |  |
Balance at End of Period | $ 1,718 us-gaap_ValuationAllowancesAndReservesBalance / us-gaap_ValuationAllowancesAndReservesTypeAxis = ghm_RestructuringReserveMember |  |

X
- Definition Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 + Details
Name: | us-gaap_ValuationAllowancesAndReservesBalance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to costs and expenses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, charged to accounts other than costs and expenses in a given period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 + Details
Name: | us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 09 -Article 12 + Details
Name: | us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAndQualifyingAccountsDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=ghm_RestructuringReserveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForDoubtfulAccountsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_WarrantyReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |