v3.5.0.1

Basis of Presentation and Summary of Significant Accounting Policies (Schedule of Subscriber System Assets, net) (Details) - USD ($) $ in Millions | Mar. 31, 2016 | Sep. 25, 2015
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Subscriber System Assets, net [Abstract] |  |
Subscriber System Assets, Gross carrying amount | $ 5,391 | $ 5,124
Subscriber System Assets, Accumulated Depreciation | (2,781) | (2,622)
Subscriber System Assets, net | $ 2,610 | $ 2,502

X
- Definition Aggregate accumulated depreciation of long-lived security system assets. + References No definition available. + Details
Name: | adt_SubscriberSystemAssetsAccumulatedDepreciation
Namespace Prefix: | adt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Gross amount of long-lived, company owned, security system assets. + References No definition available. + Details
Name: | adt_SubscriberSystemAssetsGross
Namespace Prefix: | adt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Subscriber System Assets, net [Abstract] + References No definition available. + Details
Name: | adt_SubscriberSystemAssetsnetAbstract
Namespace Prefix: | adt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, net of accumulated depreciation, of long-lived, company owned, security system assets. + References No definition available. + Details
Name: | adt_Subscribersystemassetsnet
Namespace Prefix: | adt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant