Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Deferred tax assets, gross	$ 125.4	$ 129.8
Valuation allowance	45.8	45.8
Estimated recoverable deferred income tax assets	$ 79.6	84.0
Percentage of probability of deferred income tax realized in future	50.00%
Valuation allowance, methodologies and assumptions	"more likely than not" (greater than a 50% probability)
Federal income tax at statutory rate	35.00%
Approximate Federal net operating losses ("NOLs") available to offset future taxable income		272.1
Limited net operating losses rate under "IRC Section 382"		35.0
Allowable net operating losses utilize per year under "IRC Section 382"		$ 6.1

Estimated operating loss to be utilized per year as per internal revenue code.

No definition available.

Name:	spok_EstimatedOperatingLossToBeUtilizedPerYearAsPerInternalRevenueCode
Namespace Prefix:	spok_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Operating loss carryforwards limit amount under internal revenue code.

+ References

No definition available.

+ Details

Name:	spok_OperatingLossCarryforwardsLimitAmountUnderInternalRevenueCode
Namespace Prefix:	spok_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of probability of deferred income tax realized in future.

+ References

No definition available.

+ Details

Name:	spok_PercentageOfProbabilityOfDeferredIncomeTaxRealizedInFuture
Namespace Prefix:	spok_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Deferred Tax Asset
-URI http://asc.fasb.org/extlink&oid=6510090

+ Details

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

- Definition

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

+ Details

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

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

+ Details

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

- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

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

- Definition

Describes the methodologies and assumptions on which the valuation allowance is based for deferred tax assets for which it is more likely than not that all or a portion of the deferred tax asset will not be realized.

+ References

+ Details

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