XML 52 R40.htm IDEA: XBRL DOCUMENT v3.21.1

Goodwill and Acquired Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Cumulative Value of Intangible Assets Related to Acquisition

		December 31
		2019
		US$
		Cost				Accumulated Impairment				Accumulated Amortization				Net Carrying Amount
Acquisition-related intangible assets			13,117				(3,699	)			(9,418	)			—

Schedule of Goodwill

		December 31
		2019																				2020
		US$																				US$
		Cost				Disposal of FCI				Accumulated Impairment				Foreign Currency Adjustment				Net Carrying Amount				Cost				Disposal of FCI				Accumulated Impairment				Foreign Currency Adjustment				Net Carrying Amount
Goodwill			100,129				(25,117	)			(57,485	)			(38	)			17,489				100,129				(25,117	)			(74,974	)			(38	)			—

X

- Definition

Schedule Of Intangible Assets Acquired As Part Of Business Combination [Text Block]

+ References

No definition available.

+ Details

Name:	simo_ScheduleOfIntangibleAssetsAcquiredAsPartOfBusinessCombinationTextBlock
Namespace Prefix:	simo_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267

+ Details

Name:	us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration