Shareholders' Equity - Repurchases of Common Shares in Open Market (Details) - Open market repurchases - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended					12 Months Ended
	Dec. 30, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Sep. 30, 2017
Stock Repurchase Program [Line Items]
Number of shares repurchased (in shares)	30,181	29,073	30,356	31,070	44,333	134,832
Average repurchase price per share (in dollars per share)	$ 169.26	$ 154.78	$ 148.24	$ 128.74	$ 112.78
Amount	$ 5,109	$ 4,500	$ 4,500	$ 4,001	$ 5,000	$ 18,001