Consolidated Statements of Changes in Shareholder's Equity - USD ($) $ in Millions	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income/(loss)	Noncontrolling interests
Balance at Dec. 31, 2015	$ 2,975	$ 745	$ 2	$ 2,999	$ (897)	$ 126
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	205			202		3
Foreign currency translation, net of tax	105				107	(2)
Derivative financial instruments, net of tax	1				1
Available-for-sale securities, net of tax	(2)				(2)
Balance at Jun. 30, 2016	3,284	745	2	3,201	(791)	127
Balance at Dec. 31, 2016	2,985	745	2	3,108	(995)	125
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	232			229		3
Foreign currency translation, net of tax	241				238	3
Derivative financial instruments, net of tax	3				3
Available-for-sale securities, net of tax	1				1
Balance at Jun. 30, 2017	$ 3,462	$ 745	$ 2	$ 3,337	$ (753)	$ 131