Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |
3 Months Ended | 6 Months Ended | ||||
|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Numerator: | ||||||
| Net income available to Arch | $ 1,057 | $ 1,237 | $ 2,104 | $ 1,811 | ||
| Preferred dividends | (10) | (10) | (20) | (20) | ||
| Net income (loss) available to Arch common shareholders, basic | 1,047 | 1,227 | 2,084 | 1,791 | ||
| Net income (loss) available to Arch common shareholders, diluted | $ 1,047 | $ 1,227 | $ 2,084 | $ 1,791 | ||
| Denominator: | ||||||
| Weighted average common shares outstanding — basic | 343.2 | 372.2 | 348.2 | 372.6 | ||
| Effect of dilutive common share equivalents: | ||||||
| Nonvested restricted shares | 1.4 | 1.6 | 1.5 | 1.7 | ||
| Stock options | [1] | 4.2 | 6.1 | 4.5 | 6.5 | |
| Weighted average common shares and common share equivalents outstanding — diluted | 348.8 | 379.9 | 354.2 | 380.8 | ||
| Earnings per common share: | ||||||
| Basic (per share) | $ 3.05 | $ 3.30 | $ 5.99 | $ 4.81 | ||
| Diluted (per share) | $ 3.00 | $ 3.23 | $ 5.88 | $ 4.70 | ||
| Stock options | ||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||||
| Antidilutive securities excluded from computation of earnings per common share (shares) | 2.4 | 2.2 | 2.4 | 2.4 | ||
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- Definition Net Income Per Common Share And Common Share Equivalent No definition available.
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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of call options and warrants using the treasury stock method. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of additional shares included in diluted EPS for potentially dilutive effect of nonvested equity-based payment award containing forfeitable rights to dividends or dividend equivalents, whether paid or unpaid. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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- Definition The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Details
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