Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Dec. 10, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	Teligent, Inc.
Entity Central Index Key	0000352998
Document Period End Date	Sep. 30, 2018
Entity Filer Category	Accelerated Filer
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2018
Document Type	10-Q
Amendment Flag	false
Trading Symbol	TLGT
Entity Common Stock, Shares Outstanding		53,774,221