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Liquidity (Narrative) (Details) - USD ($)		1 Months Ended	12 Months Ended
Liquidity (Narrative) (Details) - USD ($)	Mar. 26, 2020	Feb. 29, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents			$ 6,033,000	$ 9,663,000
Liquidity, management evaluation			On January 27, 2020, the Company entered into a securities purchase agreement (the "Securities Purchase Agreement") with Innoviva, Inc. ("Innoviva"), pursuant to which the Company agreed to issue and sell to Innoviva, in a private placement, up to 8,710,800 newly issued shares of common stock of the Company and warrants to purchase up to 8,710,800 shares of common stock, with an exercise price per share of $2.87 (the "Private Placement"). Each share of common stock is sold together with one common warrant (collectively, a "Common Unit"), and the per Common Unit purchase price was $2.87. The Private Placement will be completed in two separate closings, with the first closing completed in February 2020, raising gross proceeds of $2.8 million, and the second closing for additional gross proceeds of $22.2 million is expected to be completed following shareholder approval at a meeting scheduled on March 26, 2020. While management believes this plan to raise additional funds will alleviate the conditions that raise substantial doubt, these plans are not entirely within its control and cannot be assessed as being probable of occurring. The Company may not be able to secure additional financing in a timely manner or on favorable terms, if at all.Considering the Company's current cash resources, management believes the Company's existing cash resources plus the proceeds expected to be raised in the Private Placement, will be sufficient to fund the Company's planned operations into the second quarter of 2021.
Securities Purchase Agreement [Member] \| Subsequent Event [Member]
Proceeds from Issuance of Private Placement	$ 22,200,000	$ 2,800,000
Securities Purchase Agreement [Member] \| Common Stock Subject to Mandatory Redemption [Member]
Shares Issued, Price Per Share			$ 2.87
Stock Issued During Period, Shares, New Issues			8,710,800
Securities Purchase Agreement [Member] \| Warrants and Rights Subject to Mandatory Redemption [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			8,710,800