XML 76 R66.htm IDEA: XBRL DOCUMENT v3.25.1

Operating Segments and Enterprise-Wide Information - Revenue by Segment, Recognition Type, and Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2025	Mar. 30, 2024
Disaggregation of Revenue [Line Items]
Revenues	$ 171,356	$ 168,725
Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	136,520	136,701
Systems
Disaggregation of Revenue [Line Items]
Revenues	34,836	32,024
Taiwan
Disaggregation of Revenue [Line Items]
Revenues	45,362	29,877
Taiwan | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	40,747	27,179
Taiwan | Systems
Disaggregation of Revenue [Line Items]
Revenues	4,615	2,698
United States
Disaggregation of Revenue [Line Items]
Revenues	40,325	45,766
United States | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	27,784	35,596
United States | Systems
Disaggregation of Revenue [Line Items]
Revenues	12,541	10,170
China
Disaggregation of Revenue [Line Items]
Revenues	13,615	15,613
China | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	8,152	8,686
China | Systems
Disaggregation of Revenue [Line Items]
Revenues	5,463	6,927
South Korea
Disaggregation of Revenue [Line Items]
Revenues	43,171	50,717
South Korea | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	42,209	50,672
South Korea | Systems
Disaggregation of Revenue [Line Items]
Revenues	962	45
Malaysia
Disaggregation of Revenue [Line Items]
Revenues	2,600	1,863
Malaysia | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	2,552	1,608
Malaysia | Systems
Disaggregation of Revenue [Line Items]
Revenues	48	255
Japan
Disaggregation of Revenue [Line Items]
Revenues	10,319	8,542
Japan | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	5,179	4,347
Japan | Systems
Disaggregation of Revenue [Line Items]
Revenues	5,140	4,195
Europe
Disaggregation of Revenue [Line Items]
Revenues	7,781	8,849
Europe | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	3,535	3,528
Europe | Systems
Disaggregation of Revenue [Line Items]
Revenues	4,246	5,321
Singapore
Disaggregation of Revenue [Line Items]
Revenues	6,249	4,758
Singapore | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	4,871	3,516
Singapore | Systems
Disaggregation of Revenue [Line Items]
Revenues	1,378	1,242
Rest of World
Disaggregation of Revenue [Line Items]
Revenues	1,934	2,740
Rest of World | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	1,491	1,569
Rest of World | Systems
Disaggregation of Revenue [Line Items]
Revenues	443	1,171
Products transferred at a point in time
Disaggregation of Revenue [Line Items]
Revenues	166,056	164,425
Products transferred at a point in time | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	134,721	135,641
Products transferred at a point in time | Systems
Disaggregation of Revenue [Line Items]
Revenues	31,335	28,784
Products and services transferred over time
Disaggregation of Revenue [Line Items]
Revenues	5,300	4,300
Products and services transferred over time | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	1,799	1,060
Products and services transferred over time | Systems
Disaggregation of Revenue [Line Items]
Revenues	3,501	3,240
Foundry & Logic
Disaggregation of Revenue [Line Items]
Revenues	85,272	86,768
Foundry & Logic | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	85,272	86,768
Foundry & Logic | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0
DRAM
Disaggregation of Revenue [Line Items]
Revenues	48,858	45,896
DRAM | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	48,858	45,896
DRAM | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0
Flash
Disaggregation of Revenue [Line Items]
Revenues	2,390	4,037
Flash | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	2,390	4,037
Flash | Systems
Disaggregation of Revenue [Line Items]
Revenues	0	0
Systems
Disaggregation of Revenue [Line Items]
Revenues	34,836	32,024
Systems | Probe Cards
Disaggregation of Revenue [Line Items]
Revenues	0	0
Systems | Systems
Disaggregation of Revenue [Line Items]
Revenues	$ 34,836	$ 32,024

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-5

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 7: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

Reference 8: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 91
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479777/606-10-55-91

+ Details

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

X

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-41

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 270
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482964/270-10-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (ee)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 4: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 5: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-32

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-5

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-30

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-42

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-40

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482810/280-10-50-22

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-4

+ Details

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

X

- Details

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

X

- Details

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

X

- Details

Name:	srt_StatementGeographicalAxis=country_TW
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_CN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_KR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_MY
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_JP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=srt_EuropeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=country_SG
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_StatementGeographicalAxis=form_RestOfTheWorldMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredAtPointInTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TimingOfTransferOfGoodOrServiceAxis=us-gaap_TransferredOverTimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=form_FoundryLogicProductGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=form_DRAMProductGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=form_FlashProductGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ProductOrServiceAxis=form_SystemsProductGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: