| In millions, except per share items | Sep-30-21 | Sep-30-20 | Sep-30-19 | Sep-30-18 | Sep-30-17 | Sep-30-16 | Sep-30-15 | Sep-30-14 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K/A | 10-K/A |
| Sales | 3,833.0 | 3,044.0 | 4,388.0 | 4,178.0 | 3,347.0 | 3,199.0 | 362.2 | 321.6 |
| Sales growth | 25.9% | -30.6% | 5.0% | 24.8% | 4.6% | 783.3% | 12.6% | -37.9% |
| GROSS PROFIT | 505.0 | 328.0 | 640.0 | 625.0 | 497.0 | 436.0 | 83.4 | 68.0 |
| Gross margin | 13.2% | 10.8% | 14.6% | 15.0% | 14.8% | 13.6% | 23.0% | 21.1% |
| Selling, general and administrative | 270.0 | 221.0 | 256.0 | 313.0 | 266.0 | 213.0 | 4.5 | 4.5 |
| Other operating expense, net | -17.0 | -40.0 | -21.0 | -20.0 | -7.0 | -3.0 | | 2.9 |
| OPERATING INCOME | 218.0 | 332.0 | 363.0 | 292.0 | 218.0 | 204.0 | 57.6 | 42.9 |
| Operating margin | 5.7% | 10.9% | 8.3% | 7.0% | 6.5% | 6.4% | 15.9% | 13.4% |
| Other income, net | 61.0 | 46.0 | 40.0 | 26.0 | -9.0 | -1.0 | | 0.6 |
| Equity in earnings of affiliates | 34.0 | 14.0 | 31.0 | 27.0 | 48.0 | 36.0 | | |
| Interest expense, net | 79.0 | 66.0 | 57.0 | 67.0 | 119.0 | 84.0 | | |
| Provision for income taxes | -24.0 | -78.0 | -82.0 | -149.0 | 52.0 | -424.0 | | |
| INCOME FROM CONTINUING OPERATIONS | 210.0 | 248.0 | 295.0 | 129.0 | 329.0 | 579.0 | | |
| INCOME FROM DISCONTINUED OPERATIONS, net of tax | -1.0 | 1.0 | 1.0 | -3.0 | -1.0 | -4.0 | | |
| NET INCOME | 209.0 | 249.0 | 296.0 | 255.0 | 657.0 | 1,154.0 | | |
| Less: Net income attributable to noncontrolling interests | -10.0 | -4.0 | -5.0 | -9.0 | -4.0 | -2.0 | | |
| Net income | 199.0 | 245.0 | 291.0 | 117.0 | 324.0 | 573.0 | 58.1 | 43.5 |
| |
| NET INCOME ATTRIBUTABLE TO MERITOR, INC. | | | | | | | | |
| Net income from continuing operations | 200.0 | 244.0 | 290.0 | 120.0 | 325.0 | 577.0 | 58.1 | 43.5 |
| Income from discontinued operations | -1.0 | 1.0 | 1.0 | -3.0 | -1.0 | -4.0 | | |
| Net income | 199.0 | 245.0 | 291.0 | 117.0 | 324.0 | 573.0 | 58.1 | 43.5 |
| |
| BASIC EARNINGS PER SHARE | | | | | | | | |
| Continuing operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | |
| Discontinued operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | |
| |
| Basic earnings per share (in usd per share) | $2.78 | $3.31 | $3.50 | $1.34 | $3.68 | $6.36 | | |
| |
| DILUTED EARNINGS PER SHARE | | | | | | | | |
| Continuing operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | |
| Discontinued operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | | |
| Diluted earnings per share (in usd per share) | $2.73 | $3.24 | $3.37 | $1.28 | $3.59 | $6.23 | | |
| |
| Basic average common shares outstanding (in shares) | 71.7 | 74.0 | 83.2 | 87.5 | 88.0 | 90.1 | | |
| Diluted average common shares outstanding (in shares) | 72.8 | 75.6 | 86.3 | 91.2 | 90.2 | 92.0 | | |