The adjusted minimum annual aggregate royalty expense for all licensed parameters, under certain circumstances.

No definition available.

Name:	masi_AdjustedRoyaltiesPayableLicensed
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The adjusted minimum annual aggregate royalty expense for non-licensed parameters, under certain circumstances.

+ References

No definition available.

+ Details

Name:	masi_AdjustedRoyaltiesPayableNonLicensed
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The increase in the number of shares of common stock reserved for future issuance.

+ References

No definition available.

+ Details

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Namespace Prefix:	masi_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Total amount of certain expenses that are reimbursed to the Variable Interest Entity.

+ References

No definition available.

+ Details

Name:	masi_CostsReimbursed
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate amount of license fees paid for the exclusive rights to the parameter technology.

+ References

No definition available.

+ Details

Name:	masi_LicenseFeeAggregate
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The individual amount of license fees paid for exclusive rights to each individual parameter technology.

+ References

No definition available.

+ Details

Name:	masi_LicenseFeesIndividual
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Number of Companies with Rights to Intellectual Property

+ References

No definition available.

+ Details

Name:	masi_NumberofCompanieswithRightstoIntellectualProperty
Namespace Prefix:	masi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Parameters

+ References

No definition available.

+ Details

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Namespace Prefix:	masi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate amount related to the patent and licensing fee.

+ References

No definition available.

+ Details

Name:	masi_PatentandLicensingFeeAggregate
Namespace Prefix:	masi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The percentage rate used to determine the amount of expense related to royalty payments under a contractual arrangement such as payment for use of technology or intellectual property.

+ References

No definition available.

+ Details

Name:	masi_PercentageOfRoyaltyExpense
Namespace Prefix:	masi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of certain expenses that are reimbursed to the Variable Interest Entity.

+ References

No definition available.

+ Details

Name:	masi_PercentageReimbursed
Namespace Prefix:	masi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount paid to managing member or general partner, affiliate of managing member or general partner, or affiliate of limited liability company (LLC) or limited partnership (LP) for administrative services provided to the LLC or LP, for example, but not limited to, salaries, rent, or overhead costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- Definition

The amount of cash paid for royalties during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

+ Details

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

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

+ Details

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

- Definition

The amount of compensation earned (contract income) under a research and development arrangement accounted for as a contract to perform research and development for others.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6420387&loc=d3e23199-108380

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 730
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6420387&loc=d3e23221-108380

+ Details

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

- Definition

The amount of costs incurred under a research and development arrangement accounted for as a contract to perform research and development for others.

+ References

+ Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_VariableInterestEntityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ProductOrServiceAxis=masi_LicensedRainbowParametersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=masi_HandheldProductsIncorporatingRainbowTechnologyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
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_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=masi_DevelopmentPartnerMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=masi_TwoThousandSevenPlanMember
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Data Type:	na
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Period Type:

- Details

Name:	us-gaap_NatureOfExpenseAxis=masi_EngineeringrelatedPayrollExpensesMember
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Variable Interest Entities (VIEs) - Additional Information (Detail)			1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Aug. 07, 2007 shares	Jan. 02, 2007 company	Jul. 31, 2015 USD ($)	Feb. 28, 2009	Oct. 03, 2015 USD ($)	Sep. 27, 2014	Jan. 02, 2016 USD ($)	Jan. 03, 2015 USD ($)	Dec. 28, 2013 USD ($) parameter	Dec. 29, 2012	Dec. 31, 2011
Variable Interest Entity [Line Items]
Number of Companies with Rights to Intellectual Property \| company		2
Number of Parameters \| parameter									5
License Fees Individual									$ 500,000
License Fee Aggregate									2,500,000
Patent and Licensing Fee - Aggregate			$ 2,400,000
Licensed Rainbow Parameters
Variable Interest Entity [Line Items]
Percentage of royalty expense (up to)							10.00%
Handheld Products Incorporating Rainbow Technology
Variable Interest Entity [Line Items]
Percentage of royalty expense (up to)							10.00%
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Minimum aggregate royalty payments							$ 6,700,000.0	$ 5,500,000.0	5,400,000.0
Increase in royalties payable in current year							15,000,000.0
Increase in the minimum aggregate annual royalties payment after current year							2,000,000.0
Percentage reimbursed				50.00%						60.00%	50.00%
Total expenses for additional services, material and supplies							300,000	3,100,000	4,100,000
Payment for Administrative Fees							200,000	200,000	200,000
Minimum \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Minimum aggregate royalty payments							5,000,000.0
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Percentage reimbursed						60.00%
Research and Development Arrangement, Contract to Perform for Others, Costs Incurred, Gross					$ 900,000
Development Partner [Member] [Member]
Variable Interest Entity [Line Items]
Related Party Transaction, Amounts of Transaction							200,000	0	$ 0
Two Thousand Seven Plan [Member]
Variable Interest Entity [Line Items]
Common Stock Shares Added To Share Reserve \| shares	1,700,000.0
Engineering-related Payroll Expenses [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned								$ 1,600,000
Research and Development Arrangement, Contract to Perform for Others, Costs Incurred, Gross							$ 1,400,000