Finite Lived Intangible Assets Estimated Economic Life

No definition available.

Name:	uctt_FiniteLivedIntangibleAssetsEstimatedEconomicLife
Namespace Prefix:	uctt_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

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

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of assumed long-term growth in revenues, used as an input to measure fair value.

+ References

+ Details

Name:	us-gaap_FairValueInputsLongTermRevenueGrowthRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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

- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

+ Details

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

- Definition

Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, from an acquisition.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis=uctt_UctTradeNameMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=uctt_AmericanIntegrationTechnologiesReportingUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Goodwill and Purchased Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 29, 2017	Dec. 25, 2015	Dec. 29, 2017	Dec. 30, 2016	Dec. 25, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization of finite-lived intangibles			$ 5,437	$ 5,758	$ 6,212
UCT Trade name [Member]
Finite-Lived Intangible Assets [Line Items]
Value of UCT tradename			$ 9,000
Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of finite-lived intangibles				$ 2,400
Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization of finite-lived intangibles					$ 500
Trade Name [Member] \| American Integration Technologies LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Wrote off remaining book value of tradename intangible acquired		$ 500
Trade Name [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Wrote off remaining book value of tradename intangible acquired	$ 500
Minimum [Member] \| Trade Name [Member] \| American Integration Technologies LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			6 years
Minimum [Member] \| Trade Name [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			6 years
Minimum [Member] \| Customer Relationships [Member] \| American Integration Technologies LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			6 years
Minimum [Member] \| Customer Relationships [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			7 years
Minimum [Member] \| Customer Relationships [Member] \| Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			7 years
Minimum [Member] \| Intellectual Properties/Know-How [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			7 years
Minimum [Member] \| Intellectual Properties/Know-How [Member] \| Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			7 years
Maximum [Member] \| Trade Name [Member] \| American Integration Technologies LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			10 years
Maximum [Member] \| Trade Name [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			10 years
Maximum [Member] \| Customer Relationships [Member] \| American Integration Technologies LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			10 years
Maximum [Member] \| Customer Relationships [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			12 years
Maximum [Member] \| Customer Relationships [Member] \| Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			12 years
Maximum [Member] \| Intellectual Properties/Know-How [Member] \| Marchi Thermal Systems Inc [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			12 years
Maximum [Member] \| Intellectual Properties/Know-How [Member] \| Miconex [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated economic lives for intangible assets			12 years
American Integration Technologies Reporting Units [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Terminal growth rate			4.20%
Discount rate			14.00%
American Integration Technologies Reporting Units [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Terminal growth rate			8.50%
Discount rate			17.50%