Organization and Limited Liability Company Matters	6 Months Ended
Organization and Limited Liability Company Matters	Jun. 30, 2017
Organization and Limited Liability Company Matters [Abstract]
Organization and Limited Liability Company Matters	1. Organization and Limited Liability Company matters: ATEL 12, LLC (the “Company” or the “Fund”) was formed under the laws of the state of California on January 25, 2007 for the purpose of equipment financing and acquiring equipment to engage in equipment leasing and sales activities. From its inception into the third quarter of 2013, the Managing Member was ATEL Associates 12, LLC (“AA12”), a Nevada limited liability company. Effective September 30, 2013, AA12 was merged into ATEL Financial Services, LLC (“AFS” or “Managing Member” or “Manager”), a wholly-owned subsidiary of ATEL Capital Group. The Fund may continue until December 31, 2030. As a limited liability company, the liability of any individual member for the obligations of the Fund is limited to the extent of capital contributions to the Fund by the individual member. As of June 30, 2017, cumulative contributions, net of rescissions and/or redemptions, totaling $29.9 million (inclusive of the $500 initial Member’s capital investment) have been received and 2,992,482 Units were issued and outstanding. The Company is governed by its Limited Liability Company Operating Agreement (“Operating Agreement”), as amended. On January 1, 2016, the Company commenced liquidation phase activities pursuant to the guidelines of the Operating Agreement. Prior thereto, the Company was in its acquisition phase and was making distributions on a monthly and quarterly basis. During the liquidation phase, periodic distributions are paid at the discretion of the Managing Member. These unaudited interim financial statements should be read in conjunction with the financial statements and notes thereto contained in the report on Form 10-K for the year ended December 31, 2016, filed with the Securities and Exchange Commission.

ATEL 12, LLC 10-Q