Investments (Schedule Of Investments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Investments Schedule [Abstract]
Equity method investments	[1]	$ 1,214	$ 1,242
Time deposits		613	665
Available-for-sale investments		508	537
Other investments		30	33
Restricted Cash and Cash Equivalents	[2]	74	68
Total		2,439	2,545
Equity Method Investments and Joint Ventures [Abstract]
Dividends received from equity method investments		247	$ 314
Undistributed earnings from equity method investments		$ 307

[1] Dividends received were $247 and $314 during 2017 and 2016. Retained earnings at December 31, 2017 include undistributed earnings from our equity method investments of $307.

[2] Reflects amounts restricted in support of our workers’ compensation programs, employee benefit programs, and insurance premiums.