Merger Transaction (Details) $ / shares in Units, $ in Millions	Sep. 02, 2016 USD ($) $ / shares shares	Mar. 31, 2017 $ / shares	Sep. 30, 2016 $ / shares
Business Acquisition [Line Items]
Tyco share consolidation ratio	0.955
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Business Combination, Consideration Transferred per Share For Share Election	$ 5.7293
Business Combination, Consideration Transferred, Shares, For Share Election | shares	0.8357
Business Combination, Consideration Transferred per Share For Cash Election	$ 34.88
Cash consideration paid to JCI Inc. shareholders | $	$ 3,864
Percent Ownership by Shareholders of Acquiror Subsequent to Acquisition	56.00%
Percent Ownership by Shareholders of Acquiree Subsequent to Acquisition	44.00%
Tyco Merger [Member]
Business Acquisition [Line Items]
Common Stock, Par or Stated Value Per Share	$ 1.00