9. Stockholders' Equity (Details Narrative) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Proceeds from public offering gross	$ 7,020,750ntn_ProceedsFromPublicOfferingGross
Proceeds from public offering, net	6,369,000	0
Stock-based compensation	282,000us-gaap_ShareBasedCompensation	132,000us-gaap_ShareBasedCompensation
Aggregate intrinsic value of options exercised	79,000
Proceeds from exercise of options	44,000	1,000
Weighted average grant-date fair value per share price	$ 0.30	$ 0.18
Unamortized compensation expense	$ 968,000
Unamortized compensation expense remaining service period	3 years 4 months 28 days
2004 Plan [Member]
Options outstanding	642,000
2010 Plan [Member]
Options outstanding	3,080,000

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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Unrecognized cost of unvested options awarded to employees as compensation.

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The cash inflow from the additional capital contribution to the entity.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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

-Publisher FASB

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average grant-date fair value of options vested.

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