A type of option that a company can buy that gives the company the right to increase its line of credit with a lender

No definition available.

Name:	swm_CreditFacilityAccordionFeature
Namespace Prefix:	swm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The maximum percentage points added to the reference rate to compute the variable rate on the debt instrument. The reference rate for US dollar borrowings is the London Interbank Offered Rate, or LIBOR. The reference rate for euro borrowings is the Euro Interbank Offered Rate.

+ References

No definition available.

+ Details

Name:	swm_DebtInstrumentBasisSpreadOnVariableRateMaximum
Namespace Prefix:	swm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum percentage points added to the reference rate to compute the variable rate on the debt instrument. The reference rate for US dollar borrowings is the London Interbank Offered Rate, or LIBOR. The reference rate for euro borrowings is the Euro Interbank Offered Rate.

+ References

No definition available.

+ Details

Name:	swm_DebtInstrumentBasisSpreadOnVariableRateMinimum
Namespace Prefix:	swm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	swm_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentageMaximum
Namespace Prefix:	swm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The minimum fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	swm_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentageMinimum
Namespace Prefix:	swm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the conditions for borrowing under the credit facility including the nature of any restrictions.

+ 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 210.5-02.19(b),22(b))

-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 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LongtermDebtTypeAxis=swm_LineOfCreditSublimitInEuroMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (Details) (USD $)	1 Months Ended	12 Months Ended
Debt (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2013	Mar. 31, 2015
Line of Credit [Member] \| Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Term		5 years
Maximum borrowings under credit facility	$ 500,000,000	$ 500,000,000
Credit facility accordion feature	200,000,000	200,000,000
Covenant provisions	the Company to maintain (a) a maximum net debt to EBITDA ratio of 3.00 and (b) a minimum interest coverage ratio of 3.50. The Company was in compliance with all of its covenants under the Credit Agreement at March 31, 2015.
Minimum margin on borrowings (in hundredths)	1.25%
Maximum margin on borrowings (in hundredths)	2.00%
Minimum annual commitment fees on undrawn amounts (in hundredths)	0.20%
Maximum annual commitment fees on undrawn amounts (in hundredths)	0.30%
Applicable interest rate (in hundredths)			1.44%
Line of Credit [Member] \| Euro Revolver [Member]
Debt Instrument [Line Items]
Applicable interest rate (in hundredths)			1.24%
Line of Credit, Sublimit In Euro [Member] \| Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowings under credit facility	$ 300,000,000	$ 300,000,000