Name:	ulbi_BusinessCombinationAdjustmentDeferredIncomeTaxesOnIntangibleAssets
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to goodwill in connection with a business combination.

No definition available.

Name:	ulbi_BusinessCombinationAdjustmentGoodwill
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to intangibles acquired in connection with a business combination.

No definition available.

Name:	ulbi_BusinessCombinationAdjustmentIntangibleAssets
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to inventory acquired in connection with a business combination.

No definition available.

Name:	ulbi_BusinessCombinationAdjustmentInventory
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to prepaid and other current assets acquired in connection with a business combination.

No definition available.

Name:	ulbi_BusinessCombinationAdjustmentPrepaidsAndOtherCurrentAssets
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to property, plant, and equipment acquired in connection with a business combination.

No definition available.

Name:	ulbi_BusinessCombinationAdjustmentPropertyPlantAndEquipment
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The payments to acquire businesses based on the difference between actual and estimated amounts of working capital.

No definition available.

Name:	ulbi_PaymentsToAcquireBusinessesNetOfCashAcquiredWorkingCapitalAdjustment
Namespace Prefix:	ulbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

Name:	us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e1043-128460

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

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6578-128477

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6911251&loc=d3e6613-128477

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

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

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73530397&loc=d3e4845-128472

Name:	us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of inventory reserves for last-in first-out (LIFO) and other inventory valuation methods.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66092785&loc=d3e4492-108314

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 210.5-02.6(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_InventoryAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

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

Name:	us-gaap_BusinessAcquisitionAxis=ulbi_AccutronicsLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

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

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=ulbi_CustomerContractsAndRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_IntellectualPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: