Consolidated Statements of Total Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Comprehensive Income
Shareholders' comprehensive income (loss)	$ 689	$ 728
Comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to redeemable noncontrolling interests	2	(2)
Net income (loss) attributable to other noncontrolling interests	0	(3)
Other comprehensive income (loss) attributable to redeemable noncontrolling interests	(2)	(2)
Total comprehensive income (loss) attributable to noncontrolling interests	0	(7)
Total comprehensive income	$ 689	$ 721