Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The income tax expense increased between quarterly periods from $564 million in 2020 to $779 million in 2021. The company's income before income tax expense decreased $1.97 billion from $4.15 billion in 2020 to $2.18 billion in 2021, primarily due to lower downstream margins, higher employee costs, unfavorable foreign exchange effects, absence of a 2020 gain on the sale of Philippines assets and lower sales volumes, partially offset by higher prices. The company’s effective tax rate changed between quarterly periods from 14 percent in 2020 to 36 percent in 2021. The change in the effective tax rate is primarily due to the absence of a favorable international tax item, foreign exchange gains and asset sale gains that were included in income before tax but did not have significant tax impacts. In addition, the change in the effective tax rate is also impacted by the consequence of the mix effect resulting from the absolute level of earnings or losses and whether they arose in higher or lower tax rate jurisdictions. Tax positions for Chevron and its subsidiaries and affiliates are subject to income tax audits by many tax jurisdictions throughout the world. For the company’s major tax jurisdictions, examinations of tax returns for certain prior tax years had not been completed as of March 31, 2021. For these jurisdictions, the latest years for which income tax examinations had been finalized were as follows: United States — 2013, Nigeria — 2007, Australia — 2009, Kazakhstan — 2012 and Saudi Arabia — 2015. The company engages in ongoing discussions with tax authorities regarding the resolution of tax matters in the various jurisdictions. Both the outcomes for these tax matters and the timing of resolution and/or closure of the tax audits are highly uncertain. However, it is reasonably possible that developments regarding tax matters in certain tax jurisdictions may result in significant increases or decreases in the company’s total unrecognized tax benefits within the next 12 months. Given the number of years that still remain subject to examination and the number of matters being examined in the various tax jurisdictions, the company is unable to estimate the range of possible adjustments to the balance of unrecognized tax benefits.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.