XML 66 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9

Investments - Fair Value of Short-Term Available-for-Sale and Trading Investments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	$ 129,594us-gaap_AvailableForSaleSecuritiesCurrent	$ 299,715us-gaap_AvailableForSaleSecuritiesCurrent
Fair value of short-term securities	129,594us-gaap_ShortTermInvestments	300,715us-gaap_ShortTermInvestments
Time Deposits and Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	20,900us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = mksi_CommercialPaperCertificatesOfDepositTimeDepositsAndOtherMoneyMarketInstrumentsMember	64,989us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = mksi_CommercialPaperCertificatesOfDepositTimeDepositsAndOtherMoneyMarketInstrumentsMember
Bankers Acceptance Drafts [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	82us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_BankersAcceptanceMember	491us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_BankersAcceptanceMember
Commercial Paper [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments		53,434us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_CommercialPaperMember
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	24,020us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = mksi_CorporateObligationsMember	18,351us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = mksi_CorporateObligationsMember
Municipal Bonds [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	2,099us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_MunicipalBondsMember
U.S. Agency Obligations [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	82,493us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember	162,450us-gaap_AvailableForSaleSecuritiesCurrent / us-gaap_InvestmentTypeAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Mutual Funds [Member]
Schedule of Investments [Line Items]
Fair value of short-term securities		$ 1,000us-gaap_TradingSecurities / us-gaap_InvestmentTypeAxis = us-gaap_EquityFundsMember

X

- Definition

Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

+ Details

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

X

- Details

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

X

- Definition

Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph g

-Article 7

+ Details

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

X

- Definition

Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.4)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

X

- Details

Name:	us-gaap_InvestmentTypeAxis=mksi_CommercialPaperCertificatesOfDepositTimeDepositsAndOtherMoneyMarketInstrumentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=mksi_CorporateObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_BankersAcceptanceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_EquityFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: