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, 2018	$ 2,849	$ 745	$ 2	$ 2,874	$ (925)	$ 153
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	188			177		11
Foreign currency translation, net of tax	33				33	0
Derivative financial instruments, net of tax	(36)				(36)
Adjustment to adopt new accounting guidance | Accounting Standards Update 2018-02	0			(97)	97
Balance at Jun. 30, 2019	3,034	745	2	2,954	(831)	164
Balance at Mar. 31, 2019	2,954	745	2	2,875	(829)	161
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	84			79		5
Foreign currency translation, net of tax	18				20	(2)
Derivative financial instruments, net of tax	(22)				(22)
Balance at Jun. 30, 2019	3,034	745	2	2,954	(831)	164
Balance at Dec. 31, 2019	3,236	745	2	3,162	(845)	172
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	158			149		9
Foreign currency translation, net of tax	(182)				(180)	(2)
Derivative financial instruments, net of tax	13				13
Adjustment to adopt new accounting guidance | Accounting Standards Update 2016-13	(13)			(13)
Balance at Jun. 30, 2020	3,212	745	2	3,298	(1,012)	179
Balance at Mar. 31, 2020	3,016	745	2	3,239	(1,145)	175
Increase (Decrease) in Shareholder's Equity [Roll Forward]
Profit of consolidated companies	64			59		5
Foreign currency translation, net of tax	125				126	(1)
Derivative financial instruments, net of tax	7				7
Balance at Jun. 30, 2020	$ 3,212	$ 745	$ 2	$ 3,298	$ (1,012)	$ 179