Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 05, 2022
Cover [Abstract]
Entity Registrant Name	NextNav Inc.
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		101,390,237
Amendment Flag	false
Entity Central Index Key	0001865631
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	false
Entity Ex Transition Period	false
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-40985
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	87-0854654
Entity Address, Address Line One	1775 Tysons Blvd.
Entity Address, Address Line Two	5th Floor
Entity Address, City or Town	McLean
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22102
City Area Code	800
Local Phone Number	775-0982
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	NN
Security Exchange Name	NASDAQ