Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 25, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-08568
Entity Registrant Name	Teligent, Inc.
Entity Central Index Key	0000352998
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	01-0355758
Entity Address, Address Line One	105 Lincoln Ave.
Entity Address, City or Town	Buena
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08310
City Area Code	856
Local Phone Number	697-1441
Title of 12(b) Security	Common Stock, Par Value $0.01 Per Share
Trading Symbol	TLGT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 27.4
Entity Common Stock, Shares Outstanding		53,899,495
Documents Incorporated by Reference	The following documents (or parts thereof) are incorporated by reference into the following parts of this Form 10-K: Certain information required in Part III of this Annual Report on Form 10-K is incorporated from the Registrant’s Proxy Statement for the Annual Meeting of Stockholders to be held on May 19, 2020.