Note 2 - Stock-Based Compensation and Stock Option Activity (Detail) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Investment Options, Expiration Date	Dec. 31, 2008
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number (in Shares)	1,097,236
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in Shares)	1,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	10 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	491,074
Share-based Compensation Arrangement by Share-based Payment Award, Percentage of Outstanding Stock Maximum	1.00%
Stock Issued During Period, Value, Share-based Compensation, Forfeited (in Dollars)	$ 62,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
Share Price (in Dollars per share)	$ 3.68
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)	$ 1.44	$ 1.85
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value (in Dollars)	34,362	91,758
Proceeds from Stock Options Exercised (in Dollars)	75,000	152,000
Initial Option Grants [Member] \| Onvia 2000 Directors Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
In The Money Options Outstanding [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in Shares)	526,702
In The Money Options Exercisable [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number (in Shares)	195,715
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	4 years 328 days	5 years 292 days
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized (in Dollars)	317,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	1 year 211 days
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized (in Dollars)	$ 19,593
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	1 year
Onvia 2008 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Onvia 2000 Directors Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	1 year
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent	85.00%
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	60,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	20.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	5 years
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage	25.00%
Vest In Four Or Five Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number (in Shares)	655,306
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in Shares)	777,768
Incremental Increase In Shares Authorized [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)	60,000

Expiration date of the option.

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

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-Article 12

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-Footnote 5

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