Acquisitions, Goodwill and Intangible Assets - B/E Aerospace Narrative (Details) - USD ($)			3 Months Ended
	Apr. 13, 2017	Dec. 16, 2016	Dec. 31, 2017	Sep. 30, 2017	Apr. 10, 2017
Business Acquisition [Line Items]
Net increase to goodwill			$ 41,000,000
Goodwill			9,206,000,000	$ 9,158,000,000
Unsecured debt
Business Acquisition [Line Items]
Issuance of debt					$ 4,650,000,000
B/E Aerospace
Business Acquisition [Line Items]
Purchase price	$ 6,536,000,000
Assumption of net debt	2,000,000,000
Net increase to goodwill			41,000,000
Goodwill	7,226,000,000
Expected amount of tax deductible goodwill	$ 0
Sales			716,000,000
Net income			76,000,000
B/E Aerospace | Accounts payable
Business Acquisition [Line Items]
Unpaid transaction, integration and financing costs			$ 12,000,000
B/E Aerospace | Unsecured debt
Business Acquisition [Line Items]
Issuance of debt					$ 4,350,000,000
Borrowings under term loan facility		$ 1,500,000,000