Document and Entity Information Document - $ / shares	3 Months Ended
	Mar. 31, 2020	Apr. 30, 2020	Dec. 31, 2019
Entity [Abstract]
Document Quarterly Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock, par value $0.01 per share
Entity Tax Identification Number	47-4116383
Entity Incorporation, State or Country Code	DE
Common Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01
Trading Symbol	ADT
Entity Registrant Name	ADT Inc.
Entity Address, Address Line One	1501 Yamato Road
Entity Address, City or Town	Boca Raton
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33431
City Area Code	561
Local Phone Number	988-3600
Entity Interactive Data Current	Yes
Entity Central Index Key	0001703056
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Entity File Number	001-38352
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		760,432,495
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Security Exchange Name	NYSE