Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period			$ (1,567)
Accumulated other comprehensive income (loss), end of period	$ (1,448)		(1,448)
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period	(1,815)	$ (1,499)	(1,567)	$ (1,684)
Other comprehensive income (loss) before reclassifications	301	(200)	42	(99)
Amounts reclassified from accumulated other comprehensive (income) loss	66	(84)	77	(108)
Other comprehensive income (loss)	367	(284)	119	(207)
Accumulated other comprehensive income (loss), end of period	(1,448)	(1,783)	(1,448)	(1,783)
Foreign currency translation
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period	(1,672)	(1,426)	(1,487)	(1,601)
Other comprehensive income (loss) before reclassifications	291	(263)	84	(186)
Amounts reclassified from accumulated other comprehensive (income) loss	0	0	22	0
Other comprehensive income (loss)	291	(263)	106	(186)
Accumulated other comprehensive income (loss), end of period	(1,381)	(1,689)	(1,381)	(1,689)
Pension and other postretirement benefits
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period	(15)	17	(3)	12
Other comprehensive income (loss) before reclassifications	(1)	0	1	0
Amounts reclassified from accumulated other comprehensive (income) loss	(7)	(8)	(21)	(22)
Other comprehensive income (loss)	(8)	(8)	(20)	(22)
Accumulated other comprehensive income (loss), end of period	(23)	9	(23)	9
Derivative financial instruments
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period	(169)	(105)	(97)	(80)
Other comprehensive income (loss) before reclassifications	3	59	(72)	53
Amounts reclassified from accumulated other comprehensive (income) loss	73	(76)	76	(86)
Other comprehensive income (loss)	76	(17)	4	(33)
Accumulated other comprehensive income (loss), end of period	(93)	(122)	(93)	(122)
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period	41	15	20	(15)
Other comprehensive income (loss) before reclassifications	8	4	29	34
Amounts reclassified from accumulated other comprehensive (income) loss	0	0	0	0
Other comprehensive income (loss)	8	4	29	34
Accumulated other comprehensive income (loss), end of period	$ 49	$ 19	$ 49	19
Adjustments to adopt new accounting guidance | Reclassification of certain tax effects from accumulated other comprehensive income | Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				108
Adjustments to adopt new accounting guidance | Reclassification of certain tax effects from accumulated other comprehensive income | Foreign currency translation
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				98
Adjustments to adopt new accounting guidance | Reclassification of certain tax effects from accumulated other comprehensive income | Pension and other postretirement benefits
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				19
Adjustments to adopt new accounting guidance | Reclassification of certain tax effects from accumulated other comprehensive income | Derivative financial instruments
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				(9)
Adjustments to adopt new accounting guidance | Reclassification of certain tax effects from accumulated other comprehensive income | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				0
Adjusted beginning balance | Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				(1,576)
Adjusted beginning balance | Foreign currency translation
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				(1,503)
Adjusted beginning balance | Pension and other postretirement benefits
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				31
Adjusted beginning balance | Derivative financial instruments
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				(89)
Adjusted beginning balance | Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), beginning of period				$ (15)