Pieris Pharmaceuticals, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Narrative (Details)

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions					1 Months Ended
	Jun. 23, 2020	Apr. 01, 2020	Mar. 31, 2020	Jan. 30, 2019	Nov. 30, 2019	Aug. 31, 2019	Jun. 30, 2020	Dec. 31, 2019	Jan. 31, 2019
Class of Stock [Line Items]
Common stock, shares authorized (in shares)							300,000,000	300,000,000
Common stock, shares issued (in shares)							52,399,152	55,212,437
Common stock, shares outstanding (in shares)							52,399,152	55,212,437
Par value of common stock (USD per share)							$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)							10,000,000	10,000,000
Preferred stock, shares issued (in shares)							14,429	11,429
Preferred stock, shares outstanding (in shares)							14,429	11,429
Par value of preferred stock (USD per share)							$ 0.001	$ 0.001
Number of shares included with each unit (in shares)					1
Number of warrants included with each unit (in shares)					1
Gross sales proceeds from common stock						$ 50.0
Preferred share exchange
Class of Stock [Line Items]
Shares of stock sold, price per share (in dollars per share)					$ 3.43
Beneficial conversion feature					$ 2.8
Private placement
Class of Stock [Line Items]
Shares of stock sold (in shares)					9,014,960
Shares of stock sold, price per share (in dollars per share)					$ 3.55
Shares of stock sold, gross consideration					$ 32.0
Shares of stock sold, net consideration					$ 31.0
Stock issued upon conversion (shares)					0.001
Notice period before increase of Beneficial Ownership Limitation					60 days
Warrants, exercise price (in dollars per share)					$ 7.10
Common Stock
Class of Stock [Line Items]
Number of securities called by each warrant					1
Common Stock \| Stock exchange, shares from existing shareholders
Class of Stock [Line Items]
Shares of stock sold (in shares)		3,000,000		5,000,000
Preferred Stock \| Preferred share exchange
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)									5,000
Shares of stock sold (in shares)		3,000		5,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)							2,907	2,907
Preferred stock, shares outstanding (in shares)							2,907	2,907
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)							5,000	5,000
Preferred stock, shares outstanding (in shares)							5,000	5,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)							3,522	3,522
Preferred stock, shares outstanding (in shares)							3,522	3,522
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)							3,000	0
Preferred stock, shares outstanding (in shares)							3,000	0
Series D Preferred Stock \| Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		3,000
Par value of preferred stock (USD per share)			$ 0.001
Stock issued upon conversion (shares)			1,000
Notice period before increase of Beneficial Ownership Limitation			61 days
Common stock ownership limit (as a percent)			9.99%
Beneficial ownership limitation (as a percent)			19.99%
2020 Employee, Director and Consultant Equity Incentive Plan
Class of Stock [Line Items]
Shares of stock authorized pursuant to the 2019 Plan (shares)	3,500,000
2019 Plan
Class of Stock [Line Items]
Shares of stock terminated under the 2018 Plan (shares)	1,579,678
Maximum \| Private placement
Class of Stock [Line Items]
Warrants, term					5 years