Income Taxes - Schedule of Difference Between United States Federal Statutory Rate and Effective Tax Rate (Detail)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Federal income tax at statutory rate	35.00%	35.00%	35.00%
State income taxes, net of Federal tax benefit	4.40%	3.80%	3.40%
State law changes	0.00%	0.00%	0.30%
Nondeductible compensation expense	0.00%	1.80%	0.00%
Change in deferred income tax rates	0.90%	(2.60%)	0.00%
Interest on income tax refunds	0.00%	0.00%	0.10%
Change in valuation allowance	(18.60%)spok_ChangeInValuationAllowancePercent	1.20%spok_ChangeInValuationAllowancePercent	1.40%spok_ChangeInValuationAllowancePercent
Other	2.40%	0.10%	1.40%
Effective tax rate	24.10%	39.30%	41.40%

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Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, State and Local Income Taxes, Percent

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Income Tax Reconciliation Interest On Income Tax Refund

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the income tax rates.

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