XML 66 R56.htm IDEA: XBRL DOCUMENT
v3.21.1

Derivatives - Additional Information (Details) £ in Millions | 3 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Mar. 31, 2021 USD ($) | Mar. 31, 2020 USD ($) | Apr. 21, 2021 GBP (£) | Jan. 26, 2021 GBP (£) | Sep. 11, 2019 USD ($) | Sep. 11, 2019 EUR (€) | Jan. 29, 2019 USD ($) | Jan. 29, 2019 EUR (€) | Oct. 24, 2018 USD ($) | Oct. 24, 2018 EUR (€)
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, fixed rate (percent) |  |  |  |  | 1.724% | 1.724% |  |  |  |
Derivative, notional amount |  |  |  |  | $ 185,000,000 |  |  |  |  |
Cross Currency Interest Rate Contract |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount |  |  |  |  |  |  |  |  | $ 75,000,000 | € 65,400,000
Cross Currency Interest Rate Contract | Net Investment Hedging |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative amounts excluded from effectiveness testing as interest expense | $ 1,100,000 | $ 2,000,000.0 |  |  |  |  |  |  |  |
Cross Currency Interest Rate Contract | Dollars |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, fixed rate (percent) |  |  |  |  | 6.875% | 6.875% | 4.0525% | 4.0525% |  |
Derivative, notional amount |  |  |  |  | $ 100,000,000 |  | $ 75,000,000 |  |  |
Cross Currency Interest Rate Contract | Euro |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, fixed rate (percent) |  |  |  |  | 5.638% | 5.638% | 6.875% | 6.875% |  |
Derivative, notional amount | € |  |  |  |  |  | € 90,900,000 |  | € 66,000,000.0 |  |
Cross Currency Interest Rate Contract | Long |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, fixed rate (percent) |  |  |  |  |  |  |  |  | 6.875% | 6.875%
Cross Currency Interest Rate Contract | Short |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, fixed rate (percent) |  |  |  |  |  |  |  |  | 3.6725% | 3.6725%
Foreign Exchange Future |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | £ |  |  |  | £ 439.0 |  |  |  |  |  |
Foreign Exchange Future | Subsequent event |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | £ |  |  | £ 9.6 |  |  |  |  |  |  |
September 13, 2019 - December 31, 2020 |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | 185,000,000 |  |  |  |  |  |  |  |  |
December 31, 2020 - December 31, 2021 |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | 150,000,000 |  |  |  |  |  |  |  |  |
December 31, 2021 - January 31, 2027 |  |  |  |  |  |  |  |  |  |
Derivative [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount | $ 100,000,000 |  |  |  |  |  |  |  |  |

X
- Definition Amount of gain (loss) from excluded component of derivative hedge, recognized in earnings. Excludes recognition under systematic and rational method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 45 -Paragraph 1A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121577181&loc=SL110061172-113977 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeExcludedComponentGainLossRecognizedInEarnings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
Name: | us-gaap_DerivativeFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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 No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CrossCurrencyInterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_NetInvestmentHedgingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_USD
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_LongMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PositionAxis=us-gaap_ShortMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeFutureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardDateAxis=swm_September132019December312020Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardDateAxis=swm_December312020December312021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardDateAxis=swm_December312021January312027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |