Consolidated Statements of Total Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement Of Comprehensive Income
Shareholders' comprehensive income (loss)	$ 2,247	$ 2,537	$ 1,735
Comprehensive income (loss) attributable to noncontrolling interests:
Net income (loss) attributable to redeemable noncontrolling interests	9	0	(7)
Net income (loss) attributable to other noncontrolling interests	0	(5)	(17)
Other comprehensive income (loss) attributable to redeemable noncontrolling interests	(15)	(3)	(10)
Total comprehensive income (loss) attributable to noncontrolling interests	(6)	(8)	(34)
Total comprehensive income	$ 2,241	$ 2,529	$ 1,701