Merger Transaction Merger Transaction (Details)	6 Months Ended
	Mar. 31, 2016 USD ($) $ / shares
Merger Transaction [Abstract]
Cash consideration election option for the Company's shareholders at time of merger	$ 34.88
Amount JCI shareholders to receive at time of merger | $	$ 3,864,000,000.00
Merger, issued and unissued ordinary share of Tyco at time of Merger	$ 0.955
Ownership Percentage of New Entity, JCI shareholders	56.00%
Ownership Percentage of New Entity, Tyco Shareholders	44.00%
Shareholder votes needed to approve merger	75.00%
Combined Company, Board of Directors Post Merger	11
Combined Company, Board of Directors from JCI Prior to Merger	6
Combined Company, Board of Directors from Tyco Prior to Merger	5
Combined Company, Board of Directors Mutually Agreed Upon, Prior to Merger	9
Combined Company, Board of Director serving as Independent Lead Director from JCI, Prior to Merger	1
Period for which Alex Molinaroli will serve as Chairman and CEO of Combined Company	18-month
Period for which Alex Molinaroli will serve as Executive Chair of the Combined Company, Following his time as Chairman and CEO	12 months
Period after the Second Succession Date in which the non-executive directors of the combined company can vote for Chairmand and CEO	3 months
Affirmative Votes Needed to Affirm Chairman and CEO	75.00%