Schedule II - Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Accounts Receivable - Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	$ 854,000	$ 1,019,000	$ 947,000
Charged to cost and expense	184,000	(47,000)	166,000
Amounts written off	409,000	118,000	94,000
Balance at end of period	629,000	854,000	1,019,000
Accounts Receivable - Allowance for Customer-Payment Discrepancies [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	577,000	514,000	280,000
Charged to cost and expense	91,000	(10,000)	536,000
Amounts written off	(184,000)	(73,000)	302,000
Balance at end of period	852,000	577,000	514,000
Inventory - Allowance for Excess and Obsolete Inventory [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period	2,708,000	2,498,000	2,164,000
Charged to cost and expense	1,635,000	1,620,000	1,814,000
Amounts written off	1,668,000	1,410,000	1,480,000
Balance at end of period	$ 2,675,000	$ 2,708,000	$ 2,498,000

Name:	us-gaap_MovementInValuationAllowancesAndReservesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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

- Definition

+ References

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- 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

+ Details

Name:	us-gaap_ValuationAllowancesAndReservesDeductions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForUncollectibleCustomersLiabilityForAcceptancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_InventoryValuationReserveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: