Stockholders' Equity - Equity Issuances (Details)		1 Months Ended		12 Months Ended
	Sep. 14, 2016 USD ($) clinical_trial_subject $ / shares	Feb. 28, 2018 USD ($) shares	Nov. 30, 2015 USD ($) shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) shares	Dec. 31, 2016 shares	Aug. 31, 2018 USD ($) shares
Class of Stock [Line Items]
Common Stock Warrants, Shares | shares					209,818
H.C. Wainwright Sales Agreement [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues | shares				149,041
Sale Of Stock, Aggregate Offering Amount Authorized Per Agreement		$ 12,000,000
Sale Of Stock, Maximum Number Of Shares Authorized Per Agreement | shares		2,790,697					4,921,260
Sale Of Stock, Commission On Gross Proceeds Due To Third Party Upon, Percent		3.00%
Proceeds from Issuance of Common Stock				$ 1,000,000
H.C. Wainwright Sales Amended Agreement [Member]
Class of Stock [Line Items]
Sale Of Stock, Aggregate Offering Amount Authorized Per Agreement							$ 25,000,000
RD Purchase Agreement [Member]
Class of Stock [Line Items]
Shares Issued, Price Per Share | $ / shares	$ 4.72
Private Purchase Agreement [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues | shares					932,204	1,400,000
Proceeds from Issuance of Common Stock, Initial Closing	$ 6,600,000
Proceeds from Issuance of Common Stock, Second Closing					$ 4,400,000
Number of Subjects, Phase 2 CLBS03 Clinical Trial, Second Closing | clinical_trial_subject	70
Aspire Capital Purchase Agreement [Member]
Class of Stock [Line Items]
Purchase Commitment, Maximum Amount Committed, Shares | shares			1,101,928
Purchase Commitment, Remaining Minimum Amount Committed			$ 30,000,000
Term Of Agreement In Months			24 months
Shares, Issued | shares					319,776
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Fair Value of Shares					$ 1,500,000