Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2016
Accounting Policies [Abstract]
Significant Estimates and Assumptions [Text Block]	Significant Estimates and Assumptions The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of sales and expenses during the reporting periods. As described in the Company's annual report on Form 10-K, the most significant estimates and assumptions by management affect the Company’s revenue recognition, valuation of accounts receivable, valuation of inventory, assumptions used to determine fair value of goodwill and intangible assets, deferred tax assets and related valuation allowance, stock-based compensation, warranty and accounting for contingencies. The Company has reviewed these estimates and determined that these remain the most significant estimates for the three months ended March 31, 2016. There have been no material changes to the significant accounting policies previously disclosed in the Company’s annual report on Form 10-K for the year ended December 31, 2015. Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. Changes in estimates are recorded in the period in which they become known. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances. The Company has accounted for its $19,000 contract received in October 2014 from an international military customer to purchase TACNAV products and services under ASC 605-25, Multiple-Element Arrangements. This contract includes program management and engineering services expected to be delivered through 2017, and hardware shipments fulfilled in 2015 and expected to be fulfilled in 2016, as well as out-year support services. The revenue for these services is recognized using the proportional performance accounting method. The Company limits the amount of revenue recognized for delivered elements to the amount that is not contingent on the future delivery of products or services, future performance obligations, or subject to customer-specific return or refund privileges. Total revenue recognized on this contract for the three months ended March 31, 2016 and 2015 was approximately $30 and $300, respectively

Significant Estimates and Assumptions

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of sales and expenses during the reporting periods. As described in the Company's annual report on Form 10-K, the most significant estimates and assumptions by management affect the Company’s revenue recognition, valuation of accounts receivable, valuation of inventory, assumptions used to determine fair value of goodwill and intangible assets, deferred tax assets and related valuation allowance, stock-based compensation, warranty and accounting for contingencies. The Company has reviewed these estimates and determined that these remain the most significant estimates for the three months ended March 31, 2016. There have been no material changes to the significant accounting policies previously disclosed in the Company’s annual report on Form 10-K for the year ended December 31, 2015.

Although the Company regularly assesses these estimates, actual results could differ materially from these estimates. Changes in estimates are recorded in the period in which they become known. The Company bases its estimates on historical experience and various other assumptions that it believes to be reasonable under the circumstances.

The Company has accounted for its $19,000 contract received in October 2014 from an international military customer to purchase TACNAV products and services under ASC 605-25, Multiple-Element Arrangements. This contract includes program management and engineering services expected to be delivered through 2017, and hardware shipments fulfilled in 2015 and expected to be fulfilled in 2016, as well as out-year support services. The revenue for these services is recognized using the proportional performance accounting method. The Company limits the amount of revenue recognized for delivered elements to the amount that is not contingent on the future delivery of products or services, future performance obligations, or subject to customer-specific return or refund privileges. Total revenue recognized on this contract for the three months ended March 31, 2016 and 2015 was approximately $30 and $300, respectively