Organization - Additional Information (Details) - USD ($)					1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	24 Months Ended	28 Months Ended	85 Months Ended
	Oct. 25, 2021	Mar. 24, 2021	Mar. 31, 2020	Dec. 01, 2017	Oct. 31, 2015	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Mar. 24, 2021	Sep. 29, 2021	Sep. 29, 2021	Sep. 30, 2022
Class Of Stock [Line Items]
Common stock, shares issued						41,380,614		41,380,614					41,380,614
Issuance of common stock, Shares							1,840,160		3,116,563
Issuance of common stock, value							$ 18,976,917		$ 19,283,828
Net cash received from common stock issued									$ 18,144,300
Reinvestment of dividends, Shares						0	575,032	0	1,830,974				6,647,847
Runway Growth Holdings LLC
Class Of Stock [Line Items]
Issuance of common stock, Shares		22,564	22,564							22,564
Net cash received from common stock issued										$ 338,453
Offering price		$ 15.00	$ 15.00							$ 15.00
R. David Spreng
Class Of Stock [Line Items]
Issuance of common stock, Shares					1,667
Issuance of common stock, value					$ 25,000
Initial Private Offering
Class Of Stock [Line Items]
Issuance of common stock, Shares				18,241,157
Issuance of common stock, value				$ 275,000,000
Second Private Offering
Class Of Stock [Line Items]
Issuance of common stock, Shares											9,617,379	9,617,379
Capital commitments											$ 181,700,000	$ 181,673,500
Net cash received from common stock issued											$ 144,300,000	$ 144,260,683
IPO
Class Of Stock [Line Items]
Issuance of common stock, Shares	6,850,000
Net cash received from common stock issued	$ 93,000,000.0
Offering price	$ 14.60