Restructuring Expenses - Activity in Restructuring Liability Accounts (Detail) (2013 Restructuring [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015
Restructuring Cost and Reserve [Line Items]
Beginning Balance	$ 2,889us-gaap_RestructuringReserve
Usage	(350)us-gaap_PaymentsForRestructuring
Ending Balance	2,539us-gaap_RestructuringReserve
Relocation, move, transition travel, other [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	89
Provision-net	13
Usage	(13)
Ending Balance	89
Lease/rental terminations [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	2,800
Provision-net	(13)
Usage	(337)
Ending Balance	$ 2,450

The aggregate total amount charged against earnings for expenses incurred and estimated for restructuring pursuant to a duly authorized plan, net of any offsets or reductions in prior period estimates.

No definition available.

+ Details

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Namespace Prefix:	smsi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_PaymentsForRestructuring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Definition

Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 420

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SAB TOPIC 5.P.4(b))

-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

+ Details

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