Debt Instrument, Minimum Interest Rate

No definition available.

Name:	sono_DebtInstrumentMinimumInterestRate
Namespace Prefix:	sono_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870

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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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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

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
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+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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

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

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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

- Details

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Namespace Prefix:
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=sono_TermLoanMember
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- Details

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- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=sono_AggregateTermLoanMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=sono_CreditFacilityMember
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Balance Type:
Period Type:

- Details

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Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
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Balance Type:
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- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_BridgeLoanMember
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Balance Type:
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- Details

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- Details

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Long-term debt (Details) - USD ($)	1 Months Ended		9 Months Ended	12 Months Ended
Long-term debt (Details) - USD ($)	Jul. 31, 2018	Mar. 31, 2016	Jun. 30, 2018	Sep. 30, 2017	Oct. 31, 2015
Debt Instrument [Line Items]
Long-term debt			$ 39,686,000	$ 39,600,000
Debt, unamortized discount			$ 300,000	$ 400,000
Gordon Brothers Finance Company \| Term loan
Debt Instrument [Line Items]
Debt instrument, term		5 years
Gordon Brothers Finance Company \| Line of credit \| Term loan
Debt Instrument [Line Items]
Debt		$ 25,000,000
Debt instrument, minimum interest rate		10.50%
Gordon Brothers Finance Company \| Line of credit \| Term loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, basis spread on variable rate		10.00%
Gordon Brothers Finance Company \| Line of credit \| Term loan under Amended Term Loan
Debt Instrument [Line Items]
Debt		$ 15,000,000
Debt instrument, minimum interest rate		10.00%
Debt, interest rate, effective percentage			11.48%	10.74%
Gordon Brothers Finance Company \| Line of credit \| Term loan under Amended Term Loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, basis spread on variable rate		9.50%
Gordon Brothers Finance Company \| Line of credit \| Aggregate Term loan
Debt Instrument [Line Items]
Debt		$ 40,000,000
Gordon Brothers Finance Company \| Line of credit \| Aggregate Term loan \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, basis spread on variable rate		9.50%
Credit facility \| Credit facility \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, basis spread on variable rate			1.25%	1.25%
Credit facility \| J.P. Morgan Chase Bank, N.A. \| Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 80,000,000
Credit facility			$ 0	$ 0
Letter of credit \| J.P. Morgan Chase Bank, N.A. \| Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity					10,000,000
Borrowing capacity			$ 4,500,000	$ 4,400,000
Swing loan \| J.P. Morgan Chase Bank, N.A. \| Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity					$ 8,000,000
Subsequent Event \| J.P. Morgan Chase Bank, N.A. \| Term Loan under Credit Facility
Debt Instrument [Line Items]
Debt	$ 40,000,000
Subsequent Event \| J.P. Morgan Chase Bank, N.A. \| Line of credit \| Term Loan under Credit Facility
Debt Instrument [Line Items]
Debt	$ 40,000,000
Subsequent Event \| J.P. Morgan Chase Bank, N.A. \| Line of credit \| Term Loan under Credit Facility \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt, basis spread on variable rate	2.25%
Subsequent Event \| Credit facility \| J.P. Morgan Chase Bank, N.A. \| Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 120,000,000