Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible expenses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I)
-URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817

Name:	us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Income Taxes (Details) $ in Millions, $ in Billions	3 Months Ended
Income Taxes (Details) $ in Millions, $ in Billions	Mar. 31, 2019	Mar. 31, 2018	Aug. 31, 2016 USD ($)	Aug. 31, 2016 MXN ($)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Effective income tax rate, continuing operations	22.20%	41.30%
Timing and mix of pretax income with rates differing from US	(46.40%)
Impact of foreign exchange	3.40%
Impact of nondeductible interest	22.50%
Other reconciling items	21.70%
Mexican Tax Authority \| Tax Year 2010
Income Tax Contingency [Line Items]
Number of subsidiaries in a tax assessment			1	1
Tax assessment			$ 157	$ 3