Shareholders' Equity	12 Months Ended
Dec. 31, 2017
Shareholders' Equity [Abstract]
Shareholders' Equity	6. Shareholders’ Equity Preferred Stock OncoCyte is authorized to issue up to 5,000,000 shares of no par value preferred stock. As of December 31, 2017, no preferred shares were issued or outstanding. Common Stock OncoCyte has up to 50,000,000 shares of no par value common stock authorized. The holders of OncoCyte’s common stock are entitled to receive ratably dividends when, as, and if declared by the Board of Directors out of funds legally available. Upon liquidation, dissolution, or winding up, the holders of OncoCyte common stock are entitled to receive ratably the net assets available after the payment of all debts and other liabilities and subject to the prior rights of OncoCyte outstanding preferred shares, if any. The holders of common stock are entitled to one vote for each share held on all matters submitted to a vote of OncoCyte stockholders. The holders of common stock have no preemptive, subscription, or redemption rights. The outstanding shares of common stock are fully paid and non-assessable. Issuance of Common Stock and Warrants On August 29, 2016, OncoCyte sold an aggregate of 3,246,153 immediately separable units, with each unit consisting of one share of OncoCyte common stock and one warrant to purchase one share of OncoCyte common stock (the “2016 Warrants”), at a price of $3.25 per unit (the “Offering”). The sales were made pursuant to the terms and conditions of certain Purchase Agreements between OncoCyte and the purchasers in the Offering. The purchasers included certain OncoCyte existing shareholders other than BioTime. At the close of the Offering, BioTime’s percentage ownership of the outstanding common stock of OncoCyte declined to 51.2% through which BioTime retained a controlling interest in OncoCyte. OncoCyte received $9.8 million in net proceeds after discounts, commissions and expenses from the Offering. OncoCyte will use the proceeds from the Offering for funding its operations or for working capital or other general corporate purposes. Pursuant to the terms of the Purchase Agreements, OncoCyte agreed (i) to file a resale registration statement with the Securities and Exchange Commission, or SEC, to register for sale under the Securities Act of 1933, as amended, or the Securities Act, the shares of OncoCyte common stock sold in the Offering and the shares of OncoCyte common stock, or Warrant Shares, that may be issued if the Warrants are exercised, and (ii) to use commercially reasonable efforts to maintain the effectiveness of the resale registration statement under the Securities Act until the earlier of (a) the date that all shares of its common stock covered by the Resale Registration Statement have been sold or can be sold publicly without restriction or limitation under Rule 144 (including, without limitation, the requirement to be in compliance with Rule 144(c)(1)), or (b) August 29, 2018. 2016 Warrants and New Warrants The 2016 Warrants have an exercise price of $3.25 per Warrant Share, and may be exercised for five years from October 17, 2016, the date the 2016 Warrants became exercisable. The 2016 Warrants may be exercised on a net “cashless exercise” basis, meaning that the value of a portion of Warrant Shares may be used to pay the exercise price (rather than payment in cash), in certain circumstances, including if the Resale Registration Statement is not effective when and as required by the Purchase Agreements. The exercise price and the number of Warrant Shares will be adjusted to account for certain transactions, including stock splits, dividends paid in common stock, combinations or reverse splits of common stock, or reclassifications of common stock. Under certain provisions of the 2016 Warrants, in the event of a Fundamental Transaction, as defined in the 2016 Warrants, OncoCyte will use reasonable best efforts for the acquirer, or any successor entity other than OncoCyte, to assume the 2016 Warrants. If the acquirer does not assume the OncoCyte Offering Warrant obligations, then the acquirer shall pay the holders of 2016 Warrants an amount equal to the aggregate value equal to the Black Scholes Value, as defined in the 2016 Warrants. The payment of the Black Scholes Value shall be made in cash or such other consideration as the acquirer paid to the other OncoCyte shareholders in the Fundamental Transaction. OncoCyte is not required to net cash settle the 2016 Warrants under any circumstance. OncoCyte considered the guidance in ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. Since solely an acquirer, and not OncoCyte itself, may be required to net cash settle the 2016 Warrants in the event of a Fundamental Transaction, the 2016 Warrants are classified as equity. On February 17, 2017, certain OncoCyte investors exercised 2016 Warrants to acquire 625,000 shares of common stock at an exercise price of $3.25 per warrant for total exercise cash proceeds of $2.0 million (the "Warrant exercise"). In order to induce the investors to complete the Warrant exercise and, in conjunction with the Warrant exercise, OncoCyte issued new warrants to those investors (the "New Warrants"). Certain investors received New Warrants to purchase 200,000 shares of common stock at an exercise price of $5.50 per share and one investor received New Warrants to purchase 212,500 shares of common stock at an exercise of $3.25 per share. The New Warrants are exercisable at any time for five years from February 17, 2017. The New Warrants are classified as equity as their terms are consistent with the 2016 Warrants. For financial reporting purposes, the issuance of the New Warrants was treated as an inducement offer to certain shareholders to exercise their 2016 Warrants. Accordingly, the fair value of the New Warrants, determined using the Black-Scholes option pricing model, approximating $1.1 million was recognized by OncoCyte as a noncash charge to shareholder expense included in general and administrative expenses and a corresponding increase to equity on February 17, 2017, the issuance date. On July 21, 2017, OncoCyte entered into three forms of Warrant Exercise Agreements (each, an "Exercise Agreement") with certain holders of the 2016 Warrants providing for the cash exercise of their 2016 Warrants and the issuance of new warrants (the "July 2017 Warrants") to them. Pursuant to one form of Exercise Agreement, two investors exercised 2016 Warrants to purchase 226,923 shares of OncoCyte's common stock at the exercise price of $3.25 per share, and OncoCyte issued to them July 2017 Warrants expiring five years from the date of issue, to purchase 226,923 shares of common stock at an exercise price of $5.50 per share. Pursuant to a second form of Exercise Agreement, one investor exercised 2016 Warrants to purchase 540,000 shares of common stock at the exercise price of $3.25 per share, and OncoCyte issued to the investor a July 2017 Warrant, expiring five years from the date of issue, to purchase 270,000 shares of common stock at an exercise price of $3.25 per share. In this alternative form of Exercise Agreement, OncoCyte also agreed to use commercially reasonable efforts to file with the SEC a registration statement covering the resale of the shares of common stock issuable upon exercise of the July 2017 Warrant and to keep it continuously effective for up to five years, subject to conditions set forth in the Exercise Agreement. Pursuant to a third form of Exercise Agreement, one investor exercised 2016 Warrants to purchase 1,000,000 shares of common stock at the exercise price of $3.25 per share, and OncoCyte issued to the investor (i) a July 2017 Warrant, expiring two years from the date of issue, to purchase 500,000 shares of common stock at an exercise price of $5.50 per share, and (ii) a July 2017 Warrant, expiring two years from the date of issue, to purchase 500,000 shares of common stock at an exercise price of $3.25 per share. In this alternative form of Exercise Agreement, OncoCyte also agreed to use commercially reasonable efforts to file with the SEC a registration statement covering the resale of the shares of common stock issuable upon exercise of the July 2017 Warrant and to keep it continuously effective for up to five years, subject to conditions set forth in the Exercise Agreement. In the aggregate, upon the exercise of 2016 Warrants under the Exercise Agreements, OncoCyte received gross proceeds of approximately $5.74 million and issued July 2017 Warrants to purchase 1,496,923 shares of common stock at a weighted average price of $4.34 per share. The July 2017 Warrants are classified as equity as their terms are consistent with the 2016 Warrants. For financial reporting purposes, the issuance of the July 2017 Warrants is treated as an inducement offer to certain investors to exercise their 2016 Warrants. Accordingly, the fair value of the July 2017 Warrants, determined to be approximately $3.0 million using the Black-Scholes option pricing model, was recorded as a noncash charge to shareholder expense included in general and administrative expenses, and a corresponding increase was recorded to equity on July 21, 2017, the issuance date. As of December 31, 2017, OncoCyte has an aggregate of 2,779,221 warrants issued and outstanding at exercise prices ranging from $3.25 and $5.50 per warrant. Stock Option Exercises During the years ended December 31, 2017 and 2016, 323,019 and 99,496 shares of common stock were issued upon the exercise of stock options, from which OncoCyte received $610,000 and $218,000 in cash proceeds, respectively.

6. Shareholders’ Equity

Preferred Stock

OncoCyte is authorized to issue up to 5,000,000 shares of no par value preferred stock. As of December 31, 2017, no preferred shares were issued or outstanding.

Common Stock

OncoCyte has up to 50,000,000 shares of no par value common stock authorized. The holders of OncoCyte’s common stock are entitled to receive ratably dividends when, as, and if declared by the Board of Directors out of funds legally available. Upon liquidation, dissolution, or winding up, the holders of OncoCyte common stock are entitled to receive ratably the net assets available after the payment of all debts and other liabilities and subject to the prior rights of OncoCyte outstanding preferred shares, if any.

The holders of common stock are entitled to one vote for each share held on all matters submitted to a vote of OncoCyte stockholders. The holders of common stock have no preemptive, subscription, or redemption rights. The outstanding shares of common stock are fully paid and non-assessable.

Issuance of Common Stock and Warrants

On August 29, 2016, OncoCyte sold an aggregate of 3,246,153 immediately separable units, with each unit consisting of one share of OncoCyte common stock and one warrant to purchase one share of OncoCyte common stock (the “2016 Warrants”), at a price of $3.25 per unit (the “Offering”). The sales were made pursuant to the terms and conditions of certain Purchase Agreements between OncoCyte and the purchasers in the Offering. The purchasers included certain OncoCyte existing shareholders other than BioTime. At the close of the Offering, BioTime’s percentage ownership of the outstanding common stock of OncoCyte declined to 51.2% through which BioTime retained a controlling interest in OncoCyte. OncoCyte received $9.8 million in net proceeds after discounts, commissions and expenses from the Offering. OncoCyte will use the proceeds from the Offering for funding its operations or for working capital or other general corporate purposes.

Pursuant to the terms of the Purchase Agreements, OncoCyte agreed (i) to file a resale registration statement with the Securities and Exchange Commission, or SEC, to register for sale under the Securities Act of 1933, as amended, or the Securities Act, the shares of OncoCyte common stock sold in the Offering and the shares of OncoCyte common stock, or Warrant Shares, that may be issued if the Warrants are exercised, and (ii) to use commercially reasonable efforts to maintain the effectiveness of the resale registration statement under the Securities Act until the earlier of (a) the date that all shares of its common stock covered by the Resale Registration Statement have been sold or can be sold publicly without restriction or limitation under Rule 144 (including, without limitation, the requirement to be in compliance with Rule 144(c)(1)), or (b) August 29, 2018.

2016 Warrants and New Warrants

The 2016 Warrants have an exercise price of $3.25 per Warrant Share, and may be exercised for five years from October 17, 2016, the date the 2016 Warrants became exercisable. The 2016 Warrants may be exercised on a net “cashless exercise” basis, meaning that the value of a portion of Warrant Shares may be used to pay the exercise price (rather than payment in cash), in certain circumstances, including if the Resale Registration Statement is not effective when and as required by the Purchase Agreements. The exercise price and the number of Warrant Shares will be adjusted to account for certain transactions, including stock splits, dividends paid in common stock, combinations or reverse splits of common stock, or reclassifications of common stock.

Under certain provisions of the 2016 Warrants, in the event of a Fundamental Transaction, as defined in the 2016 Warrants, OncoCyte will use reasonable best efforts for the acquirer, or any successor entity other than OncoCyte, to assume the 2016 Warrants. If the acquirer does not assume the OncoCyte Offering Warrant obligations, then the acquirer shall pay the holders of 2016 Warrants an amount equal to the aggregate value equal to the Black Scholes Value, as defined in the 2016 Warrants. The payment of the Black Scholes Value shall be made in cash or such other consideration as the acquirer paid to the other OncoCyte shareholders in the Fundamental Transaction.

OncoCyte is not required to net cash settle the 2016 Warrants under any circumstance. OncoCyte considered the guidance in ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. Since solely an acquirer, and not OncoCyte itself, may be required to net cash settle the 2016 Warrants in the event of a Fundamental Transaction, the 2016 Warrants are classified as equity.

On February 17, 2017, certain OncoCyte investors exercised 2016 Warrants to acquire 625,000 shares of common stock at an exercise price of $3.25 per warrant for total exercise cash proceeds of $2.0 million (the "Warrant exercise"). In order to induce the investors to complete the Warrant exercise and, in conjunction with the Warrant exercise, OncoCyte issued new warrants to those investors (the "New Warrants"). Certain investors received New Warrants to purchase 200,000 shares of common stock at an exercise price of $5.50 per share and one investor received New Warrants to purchase 212,500 shares of common stock at an exercise of $3.25 per share. The New Warrants are exercisable at any time for five years from February 17, 2017.

The New Warrants are classified as equity as their terms are consistent with the 2016 Warrants. For financial reporting purposes, the issuance of the New Warrants was treated as an inducement offer to certain shareholders to exercise their 2016 Warrants. Accordingly, the fair value of the New Warrants, determined using the Black-Scholes option pricing model, approximating $1.1 million was recognized by OncoCyte as a noncash charge to shareholder expense included in general and administrative expenses and a corresponding increase to equity on February 17, 2017, the issuance date.

On July 21, 2017, OncoCyte entered into three forms of Warrant Exercise Agreements (each, an "Exercise Agreement") with certain holders of the 2016 Warrants providing for the cash exercise of their 2016 Warrants and the issuance of new warrants (the "July 2017 Warrants") to them.

Pursuant to one form of Exercise Agreement, two investors exercised 2016 Warrants to purchase 226,923 shares of OncoCyte's common stock at the exercise price of $3.25 per share, and OncoCyte issued to them July 2017 Warrants expiring five years from the date of issue, to purchase 226,923 shares of common stock at an exercise price of $5.50 per share.

Pursuant to a second form of Exercise Agreement, one investor exercised 2016 Warrants to purchase 540,000 shares of common stock at the exercise price of $3.25 per share, and OncoCyte issued to the investor a July 2017 Warrant, expiring five years from the date of issue, to purchase 270,000 shares of common stock at an exercise price of $3.25 per share. In this alternative form of Exercise Agreement, OncoCyte also agreed to use commercially reasonable efforts to file with the SEC a registration statement covering the resale of the shares of common stock issuable upon exercise of the July 2017 Warrant and to keep it continuously effective for up to five years, subject to conditions set forth in the Exercise Agreement.

Pursuant to a third form of Exercise Agreement, one investor exercised 2016 Warrants to purchase 1,000,000 shares of common stock at the exercise price of $3.25 per share, and OncoCyte issued to the investor (i) a July 2017 Warrant, expiring two years from the date of issue, to purchase 500,000 shares of common stock at an exercise price of $5.50 per share, and (ii) a July 2017 Warrant, expiring two years from the date of issue, to purchase 500,000 shares of common stock at an exercise price of $3.25 per share. In this alternative form of Exercise Agreement, OncoCyte also agreed to use commercially reasonable efforts to file with the SEC a registration statement covering the resale of the shares of common stock issuable upon exercise of the July 2017 Warrant and to keep it continuously effective for up to five years, subject to conditions set forth in the Exercise Agreement.

In the aggregate, upon the exercise of 2016 Warrants under the Exercise Agreements, OncoCyte received gross proceeds of approximately $5.74 million and issued July 2017 Warrants to purchase 1,496,923 shares of common stock at a weighted average price of $4.34 per share.

The July 2017 Warrants are classified as equity as their terms are consistent with the 2016 Warrants. For financial reporting purposes, the issuance of the July 2017 Warrants is treated as an inducement offer to certain investors to exercise their 2016 Warrants. Accordingly, the fair value of the July 2017 Warrants, determined to be approximately $3.0 million using the Black-Scholes option pricing model, was recorded as a noncash charge to shareholder expense included in general and administrative expenses, and a corresponding increase was recorded to equity on July 21, 2017, the issuance date.

As of December 31, 2017, OncoCyte has an aggregate of 2,779,221 warrants issued and outstanding at exercise prices ranging from $3.25 and $5.50 per warrant.

Stock Option Exercises

During the years ended December 31, 2017 and 2016, 323,019 and 99,496 shares of common stock were issued upon the exercise of stock options, from which OncoCyte received $610,000 and $218,000 in cash proceeds, respectively.