Stockholders' Equity (Deficit) (Warrants to Purchase Shares of Common Stock) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of Common Stock Subject to Warrants	1,040,083	5,111,107
January 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,955.00
Expiration	2020-01
Shares of Common Stock Subject to Warrants		17
March 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,955.00
Expiration	2020-03
Shares of Common Stock Subject to Warrants		7
November 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,955.00
Expiration	2021-11
Shares of Common Stock Subject to Warrants	15	15
December 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,955.00
Expiration	2021-12
Shares of Common Stock Subject to Warrants	2	2
February 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,300.00
Expiration	2025-02
Shares of Common Stock Subject to Warrants	451	451
May 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 3,300.00
Expiration	2020-05
Shares of Common Stock Subject to Warrants	6,697	6,697
May 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 656.20
Expiration	2021-05
Shares of Common Stock Subject to Warrants	9,483	9,483
June 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 656.20
Expiration	2021-05
Shares of Common Stock Subject to Warrants	4,102	4,102
June 2017 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 390.00
Expiration	2022-06
Shares of Common Stock Subject to Warrants	938	938
July 2017 [Member] | Warrants Exercise Price One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 345.00
Expiration	2022-07
Shares of Common Stock Subject to Warrants	318	318
July 2017 [Member] | Warrants Exercise Price Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 250.00
Expiration	2022-07
Shares of Common Stock Subject to Warrants	2,501	2,501
July 2017 [Member] | Warrants Exercise Price Three [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 212.60
Expiration	2022-07
Shares of Common Stock Subject to Warrants	50,006	50,006
February 2018 [Member] | Warrants Exercise Price Four [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 81.20
Expiration	2023-02
Shares of Common Stock Subject to Warrants	9,232	9,232
February 2018 [Member] | Warrants Exercise Price Five [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 65.00
Expiration	2023-02
Shares of Common Stock Subject to Warrants	92,338	92,338
October 2019 [Member] | Warrants Exercise Price Six [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 2.00
Expiration	2024-10
Shares of Common Stock Subject to Warrants	629,000	4,700,000
October 2019 [Member] | Warrants Exercise Price Seven [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise Price	$ 2.60
Expiration	2024-10
Shares of Common Stock Subject to Warrants	235,000	235,000