XML 11 R39.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Investments - Fair Value of Long-Term Available-for-Sale Investments (Detail) (USD $) In Thousands, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments | $ 237,313 us-gaap_AvailableForSaleSecuritiesNoncurrent | $ 157,201 us-gaap_AvailableForSaleSecuritiesNoncurrent
Time Deposits And Certificates of Deposit [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments |  | 48 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = mksi_TimeDepositsAndCertificatesOfDepositMember
Asset Backed Securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments | 129,242 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_AssetBackedSecuritiesMember | 75,674 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_AssetBackedSecuritiesMember
Corporate Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments | 90,114 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = mksi_CorporateObligationsMember | 64,669 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = mksi_CorporateObligationsMember
Municipal Bonds [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments | 1,880 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_MunicipalBondsMember | 1,254 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_MunicipalBondsMember
U.S. Agency Obligations [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Fair value of long-term available-for-sale investments | $ 16,077 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember | $ 15,556 us-gaap_AvailableForSaleSecuritiesNoncurrent / us-gaap_InvestmentTypeAxis = us-gaap_USGovernmentAgenciesDebtSecuritiesMember

X
- Definition Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income. + References Reference 1: 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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 + Details
Name: | us-gaap_AvailableForSaleSecuritiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_InvestmentTypeAxis=mksi_TimeDepositsAndCertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_AssetBackedSecuritiesMember
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: |