Acquisitions and Dispositions (Notes)	6 Months Ended
Jun. 30, 2025
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	2. ACQUISITIONS AND DISPOSITIONS Pending Business Combination with Dowlais Group plc In the first quarter of 2025, AAM announced that we reached an agreement with the Board of Directors of Dowlais Group plc (Dowlais) on the terms of a recommended cash and share offer to be made by AAM to acquire the entire issued and to be issued ordinary share capital of Dowlais (the Business Combination). In connection with the Business Combination, on January 29, 2025, AAM and Dowlais entered into a Co-operation Agreement. Pursuant to the Business Combination, Dowlais shareholders will be entitled to receive for each Dowlais ordinary share: 0.0881 shares of new AAM common stock and 43 pence per share in cash (approximately $0.59 per share as of June 30, 2025). The transaction has been unanimously approved by the Boards of Directors of AAM and Dowlais and has also been approved by both sets of shareholders. Following the close of the transaction, the combined company will be headquartered in Detroit, Michigan and will be led by AAM's Chairman and CEO. The transaction is expected to close in the fourth quarter of 2025, subject to receipt of regulatory approvals and satisfaction of customary closing conditions. See Note 5 - Long-Term Debt for additional detail regarding financing for the Business Combination. Disposition of AAM India Manufacturing Corporation Pvt., Ltd. In October 2024, we entered into a definitive agreement to sell our commercial vehicle axle business and related assets in India (AAM India Manufacturing Corporation Pvt., Ltd.) to Bharat Forge Limited for a sales price of $65.0 million (the India Sale Agreement). As such, the assets and liabilities associated with this business have met the criteria to be classified as held-for-sale, resulting in $61.0 million of assets and $30.4 million of liabilities classified as held-for-sale in our Condensed Consolidated Balance Sheet as of June 30, 2025. The sale of AAM India Manufacturing Corporation Pvt., Ltd. did not qualify for classification as discontinued operations as the sale does not represent a strategic shift in our business that has had, or will have, a major effect on our operations and financial results. In July 2025, we completed the sale of AAM India Manufacturing Corporation Pvt., Ltd, which is subject to customary post-closing adjustments, including a working capital true-up, that we expect will be finalized in the third quarter of 2025. We estimate that total cash proceeds from the sale, net of cash divested, will be approximately $65.0 million subsequent to post-closing adjustments, of which we collected approximately $58.0 million at closing, and the remainder is expected to be collected in the second half of 2025. For the three and six months ended June 30, 2025, we recorded an impairment charge of $8.0 million to reduce the carrying value of this business to fair value less costs to sell. Disposition of Affiliates In the first quarter of 2025, we exited our 50% ownership of both Hefei AAM Automotive Driveline & Chassis System Co., Ltd. and Liuzhou AAM Automotive Driveline System Co., Ltd. As a result, we collected $30.1 million in cash, which approximated the carrying value of our investments in these joint ventures at the time of disposition. We accounted for these Chinese joint ventures as equity method investments and, as such, their results of operations, cash flows and account balances were not consolidated in our financial statements.

In the first quarter of 2025, AAM announced that we reached an agreement with the Board of Directors of Dowlais Group plc (Dowlais) on the terms of a recommended cash and share offer to be made by AAM to acquire the entire issued and to be issued ordinary share capital of Dowlais (the Business Combination). In connection with the Business Combination, on January 29, 2025, AAM and Dowlais entered into a Co-operation Agreement.

Pursuant to the Business Combination, Dowlais shareholders will be entitled to receive for each Dowlais ordinary share: 0.0881 shares of new AAM common stock and 43 pence per share in cash (approximately $0.59 per share as of June 30, 2025). The transaction has been unanimously approved by the Boards of Directors of AAM and Dowlais and has also been approved by both sets of shareholders. Following the close of the transaction, the combined company will be headquartered in Detroit, Michigan and will be led by AAM's Chairman and CEO. The transaction is expected to close in the fourth quarter of 2025, subject to receipt of regulatory approvals and satisfaction of customary closing conditions. See Note 5 - Long-Term Debt for additional detail regarding financing for the Business Combination.

In October 2024, we entered into a definitive agreement to sell our commercial vehicle axle business and related assets in India (AAM India Manufacturing Corporation Pvt., Ltd.) to Bharat Forge Limited for a sales price of $65.0 million (the India Sale Agreement). As such, the assets and liabilities associated with this business have met the criteria to be classified as held-for-sale, resulting in $61.0 million of assets and $30.4 million of liabilities classified as held-for-sale in our Condensed Consolidated Balance Sheet as of June 30, 2025. The sale of AAM India Manufacturing Corporation Pvt., Ltd. did not qualify for classification as discontinued operations as the sale does not represent a strategic shift in our business that has had, or will have, a major effect on our operations and financial results.

In July 2025, we completed the sale of AAM India Manufacturing Corporation Pvt., Ltd, which is subject to customary post-closing adjustments, including a working capital true-up, that we expect will be finalized in the third quarter of 2025. We estimate that total cash proceeds from the sale, net of cash divested, will be approximately $65.0 million subsequent to post-closing adjustments, of which we collected approximately $58.0 million at closing, and the remainder is expected to be collected in the second half of 2025.

For the three and six months ended June 30, 2025, we recorded an impairment charge of $8.0 million to reduce the carrying value of this business to fair value less costs to sell.