American Axle & Manufacturing (AXL) 10-Q 5 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	3 Months Ended
	Mar. 31, 2017	May 03, 2017
Entity Registrant Name	AMERICAN AXLE & MANUFACTURING HOLDINGS INC
Entity Central Index Key	1,062,231
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Document Type	10-Q
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		111,180,486
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net sales	$ 1,049.9	$ 969.2
Cost of goods sold	839.2	795.2
Gross profit	210.7	174
Selling, general and administrative expenses	82.8	75.6
Restructuring and acquisition-related costs	16	0
Operating income	111.9	98.4
Interest expense	(25.5)	(23.6)
Investment income	0.6	0.6
Other income (expense), net	(1.1)	1
Income before income taxes	85.9	76.4
Income tax expense	7.5	15.3
Net income	$ 78.4	$ 61.1
Basic earnings per share	$ 1	$ 0.78
Diluted earnings per share	$ 0.99	$ 0.78

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net income	$ 78.4	$ 61.1
Other comprehensive income (loss)
Defined benefit plans, net of tax (a)	(0.3)	4.2
Foreign currency translation adjustments	11.9	15
Changes in cash flow hedges	15.5	3.4
Other comprehensive income	27.1	22.6
Comprehensive income	$ 105.5	$ 83.7

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other comprehensive income (loss), pension and other postretirement benefit plans, tax	$ 0.2	$ (2.3)

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 1,543.4	$ 481.2
Accounts receivable, net	702.5	560
Inventories, net	221.6	219.5
Prepaid expenses and other	106	75.8
Total current assets	2,573.5	1,336.5
Property, plant and equipment, net	1,143	1,093.7
Deferred income taxes	362	356.4
Goodwill	233.8	154
GM postretirement cost sharing asset	235.2	236.1
Other assets and deferred charges	314.5	271.4
Total assets	4,862	3,448.1
Current liabilities
Current portion of long-term debt	3.4	3.3
Accounts payable	527.9	382.3
Accrued compensation and benefits	106.3	139.3
Deferred revenue	24.5	24.6
Accrued expenses and other	110.6	102
Total current liabilities	772.7	651.5
Long-term debt, net	2,581.5	1,400.9
Deferred revenue	72.8	70.8
Postretirement benefits and other long-term liabilities	799.2	794.9
Total liabilities	4,226.2	2,918.1
Stockholders' equity
83.7 million shares issued as of March 31, 2017 and 83.0 million shares issued as of December 31, 2016	0.9	0.9
Paid-in capital	665.6	660.1
Retained earnings	528.1	449.7
Treasury stock at cost, 6.8 million shares as of March 31, 2017 and 6.5 million shares as of December 31, 2016	(196.3)	(191.1)
Accumulated other comprehensive loss
Defined benefit plans, net of tax	(243.8)	(243.5)
Foreign currency translation adjustments	(110.5)	(122.4)
Unrecognized loss on cash flow hedges	(8.2)	(23.7)
Total stockholders’ equity	635.8	530
Total liabilities and stockholders' equity	$ 4,862	$ 3,448.1

Condensed Consolidated Balance6

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Millions	Mar. 31, 2017	Dec. 31, 2016
Common stock, par or stated value per share	$ 0.01	$ 0.01
Treasury stock, shares	6.8	6.5
Common Stock, Shares, Issued	83.7	83

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net income	$ 78.4	$ 61.1
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	56.2	49.8
Deferred income taxes	(5.4)	7.4
Stock-based compensation	5.5	5.2
Pensions and other postretirement benefits, net of contributions	(1.7)	(1.8)
Loss on disposal of property, plant and equipment, net	0.5	0.6
Undistributed earnings in affiliate	(0.9)	(0.8)
Changes in operating assets and liabilities
Accounts receivable	(137.6)	(102.8)
Inventories	3	2.5
Accounts payable and accrued expenses	91.8	48.4
Deferred revenue	1.8	(4.2)
Other assets and liabilities	(29.3)	(39.2)
Net cash provided by operating activities	62.3	26.2
Investing activities
Purchases of property, plant and equipment	(34.9)	(50.6)
Proceeds from sale of property, plant and equipment	0.8	0.6
Purchase buyouts of leased equipment	(2.3)	0
Proceeds from sale of business, net	5.9	0
Acquisition of business, net	(144.1)	0
Net cash used in investing activities	(174.6)	(50)
Financing activities
Payments of long-term debt and capital lease obligations	(10.2)	(1.6)
Proceeds from issuance of long-term debt	1,209.4	6.2
Debt issuance costs	(21.2)	0
Purchase of treasury stock	(5.2)	(3.5)
Net cash provided by financing activities	1,172.8	1.1
Effect of exchange rate changes on cash	1.7	2.2
Net increase (decrease) in cash and cash equivalents	1,062.2	(20.5)
Cash and cash equivalents at beginning of period	481.2	282.5
Cash and cash equivalents at end of period	1,543.4	262
Supplemental cash flow information
Interest paid	17.9	17.8
Income taxes paid, net of refunds	$ 4.7	$ 31.6

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	1. ORGANIZATION AND BASIS OF PRESENTATION Organization American Axle & Manufacturing Holdings, Inc. (Holdings) and its subsidiaries (collectively, we, our, us or AAM) is a global Tier I supplier to the automotive industry. We manufacture, engineer, design and validate driveline and drivetrain systems and related components and chassis modules for light trucks, sport utility vehicles (SUVs), crossover vehicles, passenger cars and commercial vehicles. Driveline and drivetrain systems include components that transfer power from the transmission and deliver it to the drive wheels. Our driveline, drivetrain and related products include axles, driveheads, chassis modules, driveshafts, power transfer units, transfer cases, chassis and steering components, transmission parts, electric drive systems and metal formed products. Merger with Metaldyne Performance Group, Inc. On April 6, 2017, Alpha SPV I, Inc. (Merger Sub), a wholly-owned subsidiary of Holdings, merged with and into Metaldyne Performance Group, Inc. (MPG), with MPG as the surviving corporation in the merger. Upon completion of the merger, MPG became a wholly-owned subsidiary of Holdings. As a result, we are now a global Tier I supplier to the automotive, commercial and industrial markets. In addition to AAM's aforementioned driveline business, the merger with MPG has expanded our metal forming business and we now manufacture, engineer, design and validate powertrain and casting technologies. We employ over 25,000 associates, operating at more than 90 facilities in 17 countries, to support our customers on global and regional platforms with a continued focus on quality, operational excellence and technology leadership. Basis of Presentation We have prepared the accompanying interim condensed consolidated financial statements in accordance with the instructions to Form 10-Q under the Securities Exchange Act of 1934. These condensed consolidated financial statements are unaudited but include all normal recurring adjustments, which we consider necessary for a fair presentation of the information set forth herein. Results of operations for the periods presented are not necessarily indicative of the results for the full fiscal year. The balance sheet at December 31, 2016 presented herein has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by accounting principles generally accepted in the United States of America (GAAP) for complete consolidated financial statements. In order to prepare the accompanying interim condensed consolidated financial statements, we are required to make estimates and assumptions that affect the reported amounts and disclosures in our interim condensed consolidated financial statements. Actual results could differ from those estimates. The condensed consolidated financial statements presented in this Form 10-Q as of, and for the three months ended, March 31, 2017 do not include any amounts or balances of MPG as the merger was not completed until April 6, 2017. We will begin to include MPG results in our condensed consolidated financial statements in the second quarter of 2017. For further information, refer to the audited consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended December 31, 2016 . Effect of New Accounting Standards Accounting Standards Update 2017-07 On March 10, 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost . The amendments in this update require that an employer disaggregate the service cost component from the other components of defined benefit pension cost and postretirement benefit cost (net benefit cost). The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allow only the service cost component of net benefit cost to be eligible for capitalization. This guidance becomes effective at the beginning of our 2018 fiscal year, however early adoption is permitted. The guidance requires a retrospective transition method for the income statement classification of the net benefit cost components and a prospective transition method for the capitalization of the service cost component in assets. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2017-04 On January 26, 2017, the FASB issued ASU 2017-04 - Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The amendments in this update modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination, or what is referred to under existing guidance as "Step 2." Instead, under the amendments in this update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. This guidance becomes effective at the beginning of our 2020 fiscal year, however early adoption is permitted. The guidance requires a prospective transition method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2016-16 On October 24, 2016, the FASB issued ASU 2016-16 - Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory . Existing income tax guidance prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. This existing guidance is deemed an exception to the principle of comprehensive recognition of current and deferred income taxes under GAAP. Due to the limited authoritative guidance about this exception, diversity in practice exists. ASU 2016-16 eliminates this exception for intra-entity transfers of assets other than inventory and requires that entities recognize the income tax consequences when the transfers occur. This guidance becomes effective at the beginning of our 2018 fiscal year, however early adoption is permitted. The guidance requires a modified retrospective transition method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2016-02 On February 25, 2016, the FASB issued ASU 2016-02 - Leases (Topic 842) , which supersedes the existing lease accounting guidance and establishes new criteria for recognizing lease assets and liabilities. The most significant impact of the update, to AAM, is that a lessee will be required to recognize a "right-of-use" asset and lease liability for operating lease agreements that were not previously included on the balance sheet under the existing lease guidance. A lessee will be permitted to make a policy election, excluding recognition of the right-of-use asset and associated liability for lease terms of 12 months or less. Expense recognition in the statement of income along with cash flow statement classification for both financing (capital) and operating leases under the new standard will not be significantly changed from existing lease guidance. This guidance becomes effective for AAM at the beginning of our 2019 fiscal year and requires transition under a modified retrospective method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2014-09 In 2014, the FASB issued ASU 2014-09 - Revenue from Contracts with Customers (Topic 606) , and has subsequently issued ASUs 2015-14 - Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , 2016-08 - Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) , 2016-10 - Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing , 2016-12 - Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients , and 2016-20 - Revenue from Contracts with Customers (Topic 606): Technical Corrections and Improvements to Topic 606 (collectively, the Revenue Recognition ASUs). The Revenue Recognition ASUs outline a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersede most current revenue recognition guidance, including industry-specific guidance. The guidance is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. This guidance is effective for AAM beginning on January 1, 2018 and entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. We are evaluating whether we will adopt this guidance using the full retrospective or modified retrospective approach. We are concluding the assessment phase of implementing this guidance. We have evaluated each of the five steps in the new revenue recognition model, which are as follows: 1) Identify the contract with the customer; 2) Identify the performance obligations in the contract; 3) Determine the transaction price; 4) Allocate the transaction price to the performance obligations; and 5) Recognize revenue when (or as) performance obligations are satisfied. Our preliminary conclusion is that the determination of what constitutes a contract with our customers (step 1), our performance obligations under the contract (step 2), and the determination and allocation of the transaction price (steps 3 and 4) under the new revenue recognition model will not result in significant changes in comparison to the current revenue recognition guidance. With regard to recognizing revenue when (or as) a performance obligation is satisfied (step 5), we are thoroughly reviewing the language in our contracts with each customer to determine whether the customer obtains control of the goods at a point in time or over time. Under current revenue recognition guidance, we recognize revenue when products are shipped to our customers and title transfers under standard commercial terms or when realizable in accordance with our commercial agreements. Topic 606 provides certain criteria that, if met, require companies to recognize revenue as the product is produced (over time) instead of at a point of time (i.e. upon shipment). We are evaluating our contracts, including MPG contracts, in the context of the criteria for recognizing revenue over time. If we conclude that we meet the criteria for recognizing revenue over time, our timing of revenue recognition would be accelerated. We have initiated the assessment phase of evaluating the impact of Topic 606 on MPG's contracts with customers and are assessing the overall impact that the acquisition of MPG will have on our recognition of revenue. There are also certain considerations related to internal control over financial reporting that are associated with implementing the new guidance under Topic 606. We are currently evaluating our control framework for revenue recognition and identifying any changes that may need to be made in response to the new guidance. Disclosure requirements under the new guidance in Topic 606 have been significantly expanded in comparison to the disclosure requirements under the current guidance. Designing and implementing the appropriate controls over gathering and reporting the information required under Topic 606 is currently in process. Share Repurchase Program In 2016, AAM's Board of Directors authorized a share repurchase program of up to $100 million of AAM's common shares through December 31, 2018 as part of AAM's overall capital allocation strategy. The repurchase of shares may be made in the open market or in privately negotiated transactions and will be funded through available cash balances and cash flow from operations. The timing and amount of any share repurchases will be determined based on market and economic conditions, share price, alternative uses of capital and other factors. Approximately $1.5 million of shares have been repurchased under the authorized share repurchase program, leaving approximately $98.5 million available for repurchase. There were no repurchases under the program in the first quarter of 2017.

Restructuring and Acquisition-R

Restructuring and Acquisition-Related Costs	3 Months Ended
	Mar. 31, 2017
Restructuring and Related Activities [Abstract]
Business Acquisition, Integration, Restructuring and Other Related Costs [Text Block]	2. RESTRUCTURING AND ACQUISITION-RELATED COSTS In the fourth quarter of 2016, AAM initiated actions under a global restructuring program focused on creating a more streamlined organization in addition to reducing our cost structure and preparing for upcoming acquisition integration activities. A summary of this activity for the first quarter of 2017 is shown below: Severance Charges Implementation Costs Total (in millions) Accrual as of December 31, 2016 $ 0.6 $ 9.2 $ 9.8 Charges 1.2 5.6 6.8 Cash utilization (1.1 ) (1.5 ) (2.6 ) Non-cash utilization — — — Accrual adjustments — — — Accrual as of March 31, 2017 $ 0.7 $ 13.3 $ 14.0 As part of our restructuring actions, we incurred severance charges of approximately $1.2 million , as well as implementation costs, including professional expenses, of approximately $5.6 million during the three months ended March 31, 2017. Since inception of the global restructuring program, we have incurred severance charges totaling $1.8 million and implementation costs totaling $15.8 million . We expect to incur approximately $15 to $20 million of additional charges under our global restructuring program in 2017. On March 1, 2017, we completed the acquisition of USM Mexico Manufacturing LLC (USM Mexico) and on April 6, 2017, we completed the acquisition of MPG. During the three months ended March 31, 2017, we incurred the following charges related to these acquisitions: Acquisition-Related Costs Integration Expenses Total (in millions) Charges $ 3.3 $ 5.9 $ 9.2 Total restructuring and acquisition-related charges $ 16.0 Acquisition-related costs primarily consist of advisory, legal, accounting, valuation and certain other professional or consulting fees incurred. Integration expenses reflect consulting fees incurred in preparation for the acquisitions and ongoing integration activities. Total charges associated with our global restructuring program and acquisition-related charges of $16.0 million are shown on a separate line item titled "Restructuring and Acquisition-Related Costs" in our Condensed Consolidated Statements of Income.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	3. BUSINESS COMBINATIONS Acquisition of USM Mexico On March 1, 2017, AAM completed the acquisition of 100% of USM Mexico, a former subsidiary of U.S. Manufacturing Corporation (USM). The purchase price was funded entirely with available cash and the acquisition was accounted for under the acquisition method with the purchase price allocated to the identifiable assets and liabilities of the acquired company based on the respective fair values of the assets and liabilities. USM Mexico includes USM's operations in Guanajuato, Mexico, which has historically been one of the largest suppliers to AAM's Guanajuato Manufacturing Complex. This acquisition allows AAM to vertically integrate the supply chain and helps ensure continuity of supply for certain parts to our largest manufacturing facility. The following represents the estimated fair value of the assets acquired and liabilities assumed resulting from the acquisition, as well as the calculation of goodwill: (in millions) Contractual purchase price $ 162.5 Adjustments to contractual purchase price for capital equipment 4.9 Adjustment to contractual purchase price for settlement of existing accounts payable balance (22.8 ) Cash acquired (0.5 ) Adjusted purchase price, net of cash acquired $ 144.1 Accounts receivable 1.1 Inventories 4.8 Prepaid expenses and other 2.4 Property, plant and equipment 39.1 Intangible assets 31.7 Total assets acquired $ 79.1 Accounts payable 10.8 Accrued expenses and other 2.7 Deferred income tax liabilities 1.2 Net assets acquired $ 64.4 Goodwill $ 79.7 The purchase agreement specifies a period of time subsequent to the acquisition date for calculating the final working capital amount of USM Mexico as of the acquisition date. Additionally, we are in the process of reviewing the preliminary estimates of fair value based on independent appraisals and valuations of property, plant and equipment and intangible assets. As a result, the purchase price, working capital, property, plant and equipment, intangible assets and goodwill amounts as included in the table above are considered provisional and are subject to adjustment. We expect these provisional amounts to be finalized in the second quarter of 2017. None of the goodwill is expected to be deductible for tax purposes. AAM had an existing accounts payable balance of $22.8 million with USM Mexico as of the date of acquisition. As a result of the acquisition, this pre-existing accounts payable balance was settled and AAM accounted for this settlement separately from the acquisition. This resulted in a reduction of the purchase price of $22.8 million and this portion of the cash paid to acquire USM Mexico has been reflected as an operating cash outflow in our Condensed Consolidated Statement of Cash Flows for the three months ended March 31, 2017. The operating results of USM Mexico from the acquisition date through March 31, 2017 were insignificant to AAM's Condensed Consolidated Statement of Income for the three months ended March 31, 2017. Further, we have not included pro forma revenue and earnings for the three months ended March 31, 2017 and March 31, 2016 as the inclusion of USM Mexico would be insignificant to AAM's consolidated results for these periods. Acquisition of MPG On April 6, 2017, AAM completed its acquisition of 100% of the equity interests of MPG for a total purchase price of approximately $1.5 billion plus the assumption of approximately $1.7 billion in net debt (comprised of approximately $1.9 billion in debt less approximately $0.2 billion of MPG cash and cash equivalents). The acquisition of MPG will be accounted for under the acquisition method of accounting. MPG provides highly-engineered components for use in powertrain and safety-critical platforms for the global light, commercial and industrial vehicle markets. MPG produces these components using complex metal-forming manufacturing technologies and processes for a global customer base of OEMs and Tier I suppliers, which help their customers meet fuel economy, performance and safety standards. Our acquisition of MPG contributes significantly to diversifying our global customer base and end markets, while also allowing us to expand our presence as a global Tier I supplier to the commercial and industrial markets, in addition to our existing presence as a global Tier I supplier to the automotive industry. The aggregate cash consideration for the acquisition of MPG was financed using (i) the net proceeds of the issuance in March 2017 by AAM of $1.2 billion of new senior notes consisting of $700.0 million aggregate principal amount of 6.25% senior notes due 2025, and $500.0 million aggregate principal amount of 6.50% senior notes due 2027, and on April 6, 2017: (ii) borrowings by AAM of $100.0 million under a term loan that matures five years after completion of the acquisition of MPG, (iii) borrowings by AAM of $1.55 billion under a term loan that matures seven years after completion of the acquisition of MPG, and (iv) cash on hand. We are in the process of valuing MPG's assets acquired and liabilities assumed, as well as identifying and assessing any transactions to be recognized separately from the acquisition. The condensed consolidated financial statements presented in this Form 10-Q as of, and for the three months ended, March 31, 2017 do not include any amounts or balances of MPG as the merger was not completed until April 6, 2017. We will begin to include MPG results in our condensed consolidated financial statements in the second quarter of 2017. Pro Forma Financial Information Pro forma net sales for AAM, on a combined basis with MPG for the three months ended March 31, 2017 and March 31, 2016, were $1.8 billion and $1.7 billion , respectively, excluding MPG sales to AAM during those periods. These pro forma amounts were prepared as if the acquisition of MPG had been completed on January 1, 2016. The disclosure of pro forma net sales is for informational purposes only and does not purport to indicate the results that would actually have been obtained had the merger been completed on the assumed date for the periods presented, or which may be realized in the future. It is not practicable for us to provide pro forma earnings amounts for the three months ended March 31, 2017 and March 31, 2016 as the information necessary to calculate these amounts was not readily available as of the date of this filing. Goodwill The following table provides a reconciliation of changes in goodwill for the three months ended March 31, 2017: March 31, 2017 (in millions) Beginning balance $ 154.0 Acquisition of USM Mexico 79.7 Foreign currency translation 0.1 Ending balance $ 233.8 Intangible Assets As a result of the acquisition of USM Mexico, AAM identified and recognized certain intangible assets that are subject to amortization. The weighted-average amortization period for all intangible assets recognized as a result of the acquisition of USM Mexico is 13 years. The following table provides a breakout of the major intangible assets acquired by class: March 31, 2017 (in millions) Technology $ 29.5 Customer platforms 2.2 Total $ 31.7 The following table provides a reconciliation of the gross carrying amount and associated accumulated amortization for AAM's total intangible assets, which are all subject to amortization: March 31, December 31, 2017 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in millions) Capitalized computer software $ 33.1 $ (9.9 ) $ 23.2 $ 31.7 $ (8.5 ) $ 23.2 e-AAM in-process research & development 5.4 — 5.4 5.3 — 5.3 Technology 29.5 (0.2 ) 29.3 — — — Customer platforms 2.2 — 2.2 — — — Total $ 70.2 $ (10.1 ) $ 60.1 $ 37.0 $ (8.5 ) $ 28.5

Inventories

Inventories	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Inventory Disclosure [Text Block]	4. INVENTORIES We state our inventories at the lower of cost or net realizable value. The cost of our inventories is determined using the first-in first-out method. When we determine that our gross inventories exceed usage requirements, or if inventories become obsolete or otherwise not saleable, we record a provision for such loss as a component of our inventory accounts. Inventories consist of the following: March 31, 2017 December 31, 2016 (in millions) Raw materials and work-in-progress $ 220.4 $ 212.7 Finished goods 28.9 33.8 Gross inventories 249.3 246.5 Inventory valuation reserves (27.7 ) (27.0 ) Inventories, net $ 221.6 $ 219.5

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Long-term Debt [Text Block]	5. LONG-TERM DEBT Long-term debt consists of the following: March 31, 2017 December 31, 2016 (in millions) Existing Revolving Credit Facility $ — $ — 7.75% Notes due 2019 200.0 200.0 6.625% Notes due 2022 550.0 550.0 6.50% Notes due 2027 500.0 — 6.25% Notes due 2025 700.0 — 6.25% Notes due 2021 400.0 400.0 5.125% Notes due 2019 200.0 200.0 Foreign credit facilities 60.9 60.4 Capital lease obligations 5.4 5.5 Total debt 2,616.3 1,415.9 Less: Current portion of long-term debt 3.4 3.3 Long-term debt 2,612.9 1,412.6 Less: Debt issuance costs 31.4 11.7 Long-term debt, net $ 2,581.5 $ 1,400.9 Existing Revolving Credit Facility As of March 31, 2017 , the existing revolving credit facility under the Amended and Restated Credit Agreement, dated as of January 9, 2004, amended and restated as of September 13, 2013 (Existing Revolving Credit Facility) provided up to $523.5 million of revolving bank financing commitments through September 13, 2018. At March 31, 2017 , we had $507.3 million available under the Existing Revolving Credit Facility. This availability reflects a reduction of $16.2 million for standby letters of credit issued against the facility. As discussed in New Senior Secured Credit Facilities below, the Existing Revolving Credit Facility was replaced on April 6, 2017. 6.50% Notes due 2027 and 6.25% Notes due 2025 On March 23, 2017, we issued $700.0 million in aggregate principal amount of 6.25% senior notes due 2025 and $500.0 million in aggregate principal amount of 6.50% senior notes due 2027 (the Notes). Proceeds from the Notes were used primarily to fund the cash consideration related to AAM's acquisition of MPG, related fees and expenses, refinancing certain existing indebtedness of MPG and borrowings under the Existing Revolving Credit Facility together with borrowings under the New Senior Secured Credit Facilities. We paid debt issuance costs of $19.6 million in the first quarter of 2017 related to the Notes. New Senior Secured Credit Facilities In connection with our acquisition of MPG (the Acquisition) on April 6, 2017, Holdings and American Axle & Manufacturing, Inc. (AAM, Inc.) entered into a credit agreement (the Credit Agreement), among AAM, Inc., as borrower, Holdings, each financial institution party thereto as a lender (the Lenders), and JPMorgan Chase Bank, N.A., as administrative agent, pursuant to which Holdings and certain of its restricted subsidiaries (including certain subsidiaries of MPG acquired as part of the Acquisition) are required to guarantee the borrowings of AAM, Inc. thereunder and Holdings, AAM, Inc. and certain of their restricted subsidiaries are required to pledge their assets (including, without limitation, after-acquired assets), subject to certain exceptions and limitations. In connection with the Credit Agreement, Holdings, AAM, Inc. and certain of their restricted subsidiaries entered into a Collateral Agreement with JPMorgan Chase Bank, N.A., as collateral agent, and a Guarantee Agreement with JPMorgan Chase Bank, N.A., as administrative agent. Pursuant to the Credit Agreement, the Lenders agreed to provide a $100.0 million term loan A facility (the Term Loan A Facility), a $1.55 billion term loan B facility (the Term Loan B Facility) and a $900 million multi-currency revolving credit facility (the Revolving Credit Facility, and together with the Term Loan A Facility and the Term Loan B Facility, the New Senior Secured Credit Facilities). The proceeds of the Term Loan A Facility and the Term Loan B Facility were used to finance a portion of the consideration for the Acquisition, pay transaction costs, redeem in full MPG Holdco I Inc.’s 7.375% Senior Notes due 2022, and repay the existing indebtedness of AAM, Inc. under its Amended and Restated Credit Agreement, dated as of January 9, 2004, amended and restated as of September 13, 2013 and as further amended, among AAM, Inc., as borrower, Holdings, JPMorgan Chase Bank, N.A. as Administrative Agent, and each financial institution party thereto as a lender, as well as repay existing indebtedness of MPG under its Credit Agreement, dated as of October 20, 2014 and as amended as of May 8, 2015, among MPG Holdco I Inc., as guarantor, MPG, the subsidiary guarantors party thereto, and each financial institution party thereto as a lender. The proceeds of the Revolving Credit Facility will be used for general corporate purposes. We paid debt issuance costs of $1.6 million in the first quarter of 2017 related to the New Senior Secured Credit Facilities. The Term Loan A Facility and the Revolving Credit Facility will mature on April 6, 2022, and the Term Loan B Facility will mature on April 6, 2024. Borrowings under the New Senior Secured Credit Facilities bear interest at rates based on the applicable Eurodollar rate or alternate base rate, as AAM may elect, in each case plus an applicable margin determined based on AAM’s total net leverage ratio. The alternate base rate is the greatest of (a) the JPMorgan Chase Bank, N.A. prime rate, (b) the Federal Reserve Bank of New York rate plus 0.50% and (c) the adjusted Eurodollar rate plus 1.00%. The applicable margin for Eurodollar-based loans under the New Senior Secured Credit Facilities will be between 1.25% and 2.25% with respect to any loan under the Term Loan A Facility, 2.25% with respect to any loan under the Term Loan B Facility, and between 2.00% and 3.00% with respect to any loan under the Revolving Credit Facility. The applicable margin for loans subject to alternate base rate will be between 0.25% and 1.25% with respect to any loan under the Term Loan A Facility, 1.25% with respect to any loan under the Term Loan B Facility, and between 1.00% and 2.00% with respect to any loan under the Revolving Credit Facility. The Credit Agreement requires certain mandatory prepayments of outstanding loans under the Term Loan A Facility and the Term Loan B Facility, subject to certain exceptions, based on the annual excess cash flow of Holdings and its restricted subsidiaries (with step-downs to 0% based upon the total net leverage ratio, and with no prepayment required if annual excess cash flow is under a specified minimum threshold), the net cash proceeds of certain asset sales and casualty and condemnation events, subject to reinvestment rights and certain other exceptions, and the net cash proceeds of any issuance of debt not otherwise permitted under the Credit Agreement. The Credit Agreement permits AAM, Inc. to incur incremental term loan borrowings and/or increase commitments under the Revolving Credit Facility, subject to certain limitations and the satisfaction of certain conditions, in an aggregate amount not to exceed (i) $600 million, plus (ii) certain voluntary prepayments, plus (iii) additional amounts subject to pro forma compliance with a first lien net leverage ratio for Holdings and its restricted subsidiaries. The Credit Agreement contains customary affirmative and negative covenants, including, among others, financial covenants based on total net leverage and cash interest expense coverage ratios and limitations on the ability of Holdings, AAM, Inc. or their restricted subsidiaries to make certain investments, declare or pay dividends or distributions on capital stock, redeem or repurchase capital stock and certain debt obligations, incur liens, incur indebtedness, or merge, make certain acquisitions or certain sales of assets. The Credit Agreement includes customary events of default, the occurrence of which would permit the lenders to, among other things, declare the principal, accrued interest and other obligations to be immediately due and payable. Upon such default, the lenders may also seek customary remedies with respect to the collateral under the Collateral Agreement. The New Senior Secured Credit Facilities provide back-up liquidity for our foreign credit facilities. We intend to use the availability of long-term financing under the New Senior Secured Credit Facilities to refinance any current maturities related to such debt agreements that are not otherwise refinanced on a long-term basis in their local markets, except where otherwise reclassified to current portion of long-term debt on our Condensed Consolidated Balance Sheet. Foreign credit facilities We utilize local currency credit facilities to finance the operations of certain foreign subsidiaries. At March 31, 2017 , $60.9 million was outstanding under our foreign credit facilities and an additional $91.2 million was available. The weighted-average interest rate of our long-term debt outstanding was 6.7% at March 31, 2017 and 6.6% at December 31, 2016 .

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	6. FAIR VALUE Accounting Standards Codification 820 - Fair Value Measurement defines fair value as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The definition is based on an exit price rather than an entry price, regardless of whether the entity plans to hold or sell the asset. This guidance also establishes a fair value hierarchy to prioritize inputs used in measuring fair value as follows: • Level 1: Observable inputs such as quoted prices in active markets; • Level 2: Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and • Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Financial instruments The estimated fair value of our financial assets and liabilities that are recognized at fair value on a recurring basis, using available market information and other observable data, are as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Input (in millions) Balance Sheet Classification Cash equivalents $ 1,388.9 $ 1,388.9 $ 187.2 $ 187.2 Level 1 Currency forward contracts - Prepaid expenses and other Cash flow hedges 1.0 1.0 — — Level 2 Nondesignated currency forward contracts 3.0 3.0 — — Level 2 Currency forward contracts - Other assets and deferred charges Cash flow hedges 0.7 0.7 — — Level 2 Currency forward contracts - Accrued expenses and other Cash flow hedges 7.0 7.0 12.3 12.3 Level 2 Nondesignated currency forward contracts — — 1.4 1.4 Level 2 Currency forward contracts - Postretirement benefits and other long-term liabilities Cash flow hedges 2.9 2.9 11.4 11.4 Level 2 The carrying values of our cash, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to the short-term maturities of these instruments. The carrying values of our borrowings under the foreign credit facilities approximate their fair value due to the frequent resetting of the interest rates. We estimated the fair value of the amounts outstanding on our debt using available market information and other observable data, to be as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Input (in millions) Existing Revolving Credit Facility $ — $ — $ — $ — Level 2 7.75% Notes due 2019 200.0 220.3 200.0 221.0 Level 2 6.625% Notes due 2022 550.0 564.5 550.0 566.1 Level 2 6.50% Notes due 2027 500.0 500.2 — — Level 2 6.25% Notes due 2025 700.0 695.2 — — Level 2 6.25% Notes due 2021 400.0 410.0 400.0 412.0 Level 2 5.125% Notes due 2019 200.0 202.0 200.0 201.7 Level 2

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Text Block]	7. DERIVATIVES Our business and financial results are affected by fluctuations in world financial markets, including interest rates and currency exchange rates. Our hedging policy has been developed to manage these risks to an acceptable level based on management’s judgment of the appropriate trade-off between risk, opportunity and cost. We do not hold financial instruments for trading or speculative purposes. Currency forward contracts From time to time, we use foreign currency forward contracts to reduce the effects of fluctuations in exchange rates, primarily relating to the Mexican Peso, Euro, Brazilian Real, British Pound Sterling, Thai Baht, Swedish Krona, Chinese Yuan and Polish Zloty. As of March 31, 2017 , we have currency forward contracts outstanding with a notional amount of $176.3 million that hedge our exposure to changes in foreign currency exchange rates for certain payroll expenses into the fourth quarter of 2019 and certain direct and indirect inventory and other working capital items into the third quarter of 2017. The following table summarizes the reclassification of pre-tax derivative losses into net income from accumulated other comprehensive loss for those derivative instruments designated as cash flow hedges under Accounting Standards Codification 815 - Derivatives and Hedging (ASC 815): Loss Reclassified During Loss Expected to Location of Loss Three Months Ended be Reclassified Reclassified into March 31, During the Net Income 2017 2016 Next 12 Months (in millions) Currency forward contracts Cost of Goods Sold $ (2.8 ) $ (2.0 ) $ (6.0 ) See Note 12 - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (AOCI) for amounts recognized in other comprehensive income (loss) during the three months ended March 31, 2017 and March 31, 2016. The following table summarizes the amount and location of gains (losses) recognized in the Condensed Consolidated Statements of Income for those derivative instruments not designated as hedging instruments under ASC 815: Gain (Loss) Recognized During Location of Gain (Loss) Three Months Ended Recognized in March 31, Net Income 2017 2016 (in millions) Currency forward contracts Cost of Goods Sold $ 3.5 $ (0.5 ) Currency forward contracts Other Income, Net — (0.7 )

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	8. EMPLOYEE BENEFIT PLANS The components of net periodic benefit cost (credit) are as follows: Pension Benefits Three Months Ended March 31, 2017 2016 (in millions) Service cost $ 0.8 $ 0.7 Interest cost 6.8 7.3 Expected asset return (10.5 ) (10.7 ) Amortized loss 1.7 1.4 Net periodic benefit credit $ (1.2 ) $ (1.3 ) Other Postretirement Benefits Three Months Ended March 31, 2017 2016 (in millions) Service cost $ 0.1 $ 0.1 Interest cost 3.3 3.5 Amortized loss 0.2 0.1 Amortized prior service credit (0.7 ) (0.7 ) Net periodic benefit cost $ 2.9 $ 3.0 The noncurrent liabilities associated with our pension and other postretirement benefit plans are classified as postretirement benefits and other long-term liabilities on our Condensed Consolidated Balance Sheets. As of March 31, 2017 and December 31, 2016 , we have a noncurrent pension liability of $111.0 million and $113.5 million , respectively. As of March 31, 2017 and December 31, 2016 , we have a noncurrent other postretirement benefits liability of $543.6 million and $542.6 million , respectively. Due to the availability of our pre-funded pension balances (previous contributions in excess of prior required pension contributions) related to our U.S. pension plans, as well as contributions we made in 2015 for our U.K. pension plan, we are not required to make any cash payments to our pension trusts in 2017. We expect our cash payments for other postretirement benefit obligations in 2017, net of GM cost sharing, to be approximately $16 million .

Product Warranties

Product Warranties	3 Months Ended
	Mar. 31, 2017
Product Warranties Disclosures [Abstract]
Product Warranty Disclosure [Text Block]	9. PRODUCT WARRANTIES We record a liability for estimated warranty obligations at the dates our products are sold. These estimates are established using sales volumes and internal and external warranty data where there is no payment history and historical information about the average cost of warranty claims for customers with prior claims. We estimate our costs based on the contractual arrangements with our customers, existing customer warranty terms and internal and external warranty data, which includes a determination of our warranty claims and actions taken to improve product quality and minimize warranty claims. We continuously evaluate these estimates and our customers' administration of their warranty programs. We closely monitor actual warranty claim data and adjust the liability, as necessary, on a quarterly basis. The following table provides a reconciliation of changes in the product warranty liability: Three Months Ended March 31, 2017 2016 (in millions) Beginning balance $ 42.9 $ 36.6 Accruals 5.5 3.9 Payments (0.9 ) (0.5 ) Adjustment to prior period accruals (0.2 ) (3.1 ) Foreign currency translation 0.2 0.1 Ending balance $ 47.5 $ 37.0

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	10. INCOME TAXES We are required to adjust our effective tax rate each quarter to estimate our annual effective tax rate. We must also record the tax impact of certain discrete, unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, in the interim period in which they occur. In addition, jurisdictions with a projected loss for the year or a year-to-date loss where no tax benefit can be recognized are excluded from the estimated annual effective tax rate. The impact of such an exclusion could result in a higher or lower effective tax rate during a particular quarter, based upon the mix and timing of actual earnings versus annual projections. Income tax expense was $7.5 million in the three months ended March 31, 2017 as compared to $15.3 million in the three months ended March 31, 2016 . Our effective income tax rate was 8.7% in the first quarter of 2017 as compared to 20.0% in the first quarter of 2016 . Our income tax expense and effective tax rate for the three months ended March 31, 2017 are lower than our income tax expense and effective tax rate for the three months ended March 31, 2016 primarily as a result of favorable foreign tax rates, as well as a benefit in the U.S. for 2017 based on higher forecasted annual interest expense attributable to the first quarter of 2017 resulting from the issuance of our $700.0 million aggregate principal amount of 6.25% senior notes and $500.0 million aggregate principal amount of 6.50% senior notes on March 23, 2017. Our effective tax rate for the three months ended March 31, 2017 was lower than the U.S. federal statutory rate of 35% primarily as a result of the impact of these factors, which was partially offset by our inability to realize a tax benefit for current foreign losses. Based on the status of audits outside the U.S., and the protocol of finalizing audits by the relevant tax authorities, it is not possible to estimate the timing or impact of changes, if any, to previously recorded uncertain tax positions. As of March 31, 2017 and December 31, 2016, we have recorded a liability for unrecognized income tax benefits and related interest and penalties of $38.5 million and $30.7 million , respectively. In January 2016, we completed negotiations with the Mexican tax authorities to settle transfer pricing audits. Including these settlements, we made payments of $26.1 million in the first three months of 2016 to the Mexican tax authorities related to transfer pricing matters. Although it is difficult to estimate with certainty the amount of our tax liabilities for the years that remain subject to audit, we do not expect the settlements will be materially different from what we have recorded in unrecognized tax benefits. We will continue to monitor the progress and conclusions of current and future audits and will adjust our estimated liability as necessary.

Earnings Per Share (EPS)

Earnings Per Share (EPS)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	11. EARNINGS PER SHARE (EPS) We present earnings per share using the two-class method. This method allocates undistributed earnings between common shares and non-vested share based payment awards that entitle the holder to non-forfeitable dividend rights. Our participating securities include non-vested restricted stock units. The following table sets forth the computation of our basic and diluted EPS available to shareholders of common stock (excluding participating securities): Three Months Ended March 31, 2017 2016 (in millions, except per share data) Numerator Net income $ 78.4 $ 61.1 Less: Net income attributable to participating securities (1.9 ) (1.4 ) Net income attributable to common shareholders - Basic and Dilutive $ 76.5 $ 59.7 Denominators Basic common shares outstanding - Weighted-average shares outstanding 78.5 77.9 Less: Participating securities (1.9 ) (1.7 ) Weighted-average common shares outstanding 76.6 76.2 Effect of dilutive securities - Dilutive stock-based compensation 0.4 0.3 Diluted shares outstanding - Adjusted weighted-average shares after assumed conversions 77.0 76.5 Basic EPS $ 1.00 $ 0.78 Diluted EPS $ 0.99 $ 0.78 Certain exercisable stock options were excluded from the computations of diluted EPS because the exercise price of these options was greater than the average period market prices. There were no stock options excluded from the calculation of diluted EPS at March 31, 2017. The number of stock options outstanding, which were not included in the calculation of diluted EPS, was 0.2 million , with an exercise price of $26.02 , at March 31, 2016 .

Reclassifications out of Accumu

Reclassifications out of Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2017
Reclassifications out of Accumulated Other Comprehensive Income (Loss) [Abstract]
Disclosure of Reclassification Amount [Text Block]	12. RECLASSIFICATIONS OUT OF ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (AOCI) Reclassification adjustments and other activity impacting accumulated other comprehensive income (loss) during the three months ended March 31, 2017 and March 31, 2016 are as follows (in millions) : Defined Benefit Plans Foreign Currency Translation Adjustments Unrecognized Loss on Cash Flow Hedges Total Balance at December 31, 2016 $ (243.5 ) $ (122.4 ) $ (23.7 ) $ (389.6 ) Other comprehensive income (loss) before reclassifications (1.7 ) 11.9 12.7 22.9 Income tax effect of other comprehensive income (loss) before reclassifications 0.6 — — 0.6 Amounts reclassified from accumulated other comprehensive loss 1.2 (a) — 2.8 (b) 4.0 Income tax benefit reclassified into net income (0.4 ) — — (0.4 ) Net current period other comprehensive income (loss) (0.3 ) 11.9 15.5 27.1 Balance at March 31, 2017 $ (243.8 ) $ (110.5 ) $ (8.2 ) $ (362.5 ) Defined Benefit Plans Foreign Currency Translation Adjustments Unrecognized Loss on Cash Flow Hedges Total Balance at December 31, 2015 $ (223.9 ) $ (119.2 ) $ (13.4 ) $ (356.5 ) Other comprehensive income before reclassifications 5.7 15.0 1.4 22.1 Income tax effect of other comprehensive income before reclassifications (2.0 ) — — (2.0 ) Amounts reclassified from accumulated other comprehensive loss 0.8 (a) — 2.0 (b) 2.8 Income tax benefit reclassified into net income (0.3 ) — — (0.3 ) Net current period other comprehensive income 4.2 15.0 3.4 22.6 Balance at March 31, 2016 $ (219.7 ) $ (104.2 ) $ (10.0 ) $ (333.9 ) (a) The amount reclassified from AOCI included $1.4 million in cost of goods sold (COGS) and $(0.2) million in selling, general & administrative expenses (SG&A) for the three months ended March 31, 2017 and $1.1 million in COGS and $(0.3) million in SG&A for the three months ended March 31, 2016. (b) The amounts reclassified from AOCI are included in COGS.

Supplemental Guarantor Condense

Supplemental Guarantor Condensed Consolidating Financial Statements	3 Months Ended
	Mar. 31, 2017
Supplemental Guarantor Condensed Consolidating Financial Statements [Abstract]
Supplemental Guarantor Disclosure [Text Block]	13. SUPPLEMENTAL GUARANTOR CONDENSED CONSOLIDATING FINANCIAL STATEMENTS Holdings, as of March 31, 2017, had no significant assets other than its 100% ownership in AAM, Inc. and no direct subsidiaries other than AAM, Inc and Alpha SPV I, Inc (Merger Sub), which merged with and into MPG upon closing of the Acquisition. The 7.75% Notes, 6.625% Notes, 6.50% Notes, 6.25% Notes (due 2025), 6.25% Notes (due 2021) and 5.125% Notes are senior unsecured obligations of AAM, Inc.; all of which are fully and unconditionally guaranteed, on a joint and several basis, by Holdings, Merger Sub and substantially all domestic subsidiaries of AAM, Inc, which are 100% indirectly owned by Holdings. These Condensed Consolidating Financial Statements are prepared under the equity method of accounting whereby the investments in subsidiaries are recorded at cost and adjusted for the parent’s share of the subsidiaries’ cumulative results of operations, capital contributions and distributions, and other equity changes. Condensed Consolidating Statements of Income Three Months Ended March 31, (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2017 Net sales External $ — $ 296.6 $ 50.1 $ 703.2 $ — $ 1,049.9 Intercompany — 0.3 66.7 4.9 (71.9 ) — Total net sales — 296.9 116.8 708.1 (71.9 ) 1,049.9 Cost of goods sold — 277.2 94.9 539.0 (71.9 ) 839.2 Gross profit — 19.7 21.9 169.1 — 210.7 Selling, general and administrative expenses — 73.8 — 9.0 — 82.8 Restructuring and acquisition-related costs — 15.3 — 0.7 — 16.0 Operating income (loss) — (69.4 ) 21.9 159.4 — 111.9 Non-operating income (expense), net — (26.2 ) 2.4 (2.2 ) — (26.0 ) Income (loss) before income taxes — (95.6 ) 24.3 157.2 — 85.9 Income tax expense (benefit) — (2.8 ) 0.1 10.2 — 7.5 Earnings (loss) from equity in subsidiaries 78.4 91.6 (0.6 ) — (169.4 ) — Net income (loss) before royalties 78.4 (1.2 ) 23.6 147.0 (169.4 ) 78.4 Royalties — 79.6 — (79.6 ) — — Net income after royalties 78.4 78.4 23.6 67.4 (169.4 ) 78.4 Other comprehensive income, net of tax 27.1 27.1 10.5 26.4 (64.0 ) 27.1 Comprehensive income $ 105.5 $ 105.5 $ 34.1 $ 93.8 $ (233.4 ) $ 105.5 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2016 Net sales External $ — $ 283.2 $ 54.8 $ 631.2 $ — $ 969.2 Intercompany — 1.6 59.7 3.7 (65.0 ) — Total net sales — 284.8 114.5 634.9 (65.0 ) 969.2 Cost of goods sold — 276.3 92.5 491.4 (65.0 ) 795.2 Gross profit — 8.5 22.0 143.5 — 174.0 Selling, general and administrative expenses — 67.5 — 8.1 — 75.6 Operating income (loss) — (59.0 ) 22.0 135.4 — 98.4 Non-operating income (expense), net — (24.3 ) 3.0 (0.7 ) — (22.0 ) Income (loss) before income taxes — (83.3 ) 25.0 134.7 — 76.4 Income tax expense — 7.8 0.1 7.4 — 15.3 Earnings (loss) from equity in subsidiaries 61.1 92.9 (9.6 ) — (144.4 ) — Net income before royalties 61.1 1.8 15.3 127.3 (144.4 ) 61.1 Royalties — 59.3 — (59.3 ) — — Net income after royalties 61.1 61.1 15.3 68.0 (144.4 ) 61.1 Other comprehensive income, net of tax 22.6 22.6 15.7 19.8 (58.1 ) 22.6 Comprehensive income $ 83.7 $ 83.7 $ 31.0 $ 87.8 $ (202.5 ) $ 83.7 Condensed Consolidating Balance Sheets (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated March 31, 2017 Assets Current assets Cash and cash equivalents $ — $ 1,413.3 $ — $ 130.1 $ — $ 1,543.4 Accounts receivable, net — 175.3 23.9 503.3 — 702.5 Intercompany receivables — 312.0 350.5 9.0 (671.5 ) — Inventories, net — 44.0 31.6 146.0 — 221.6 Prepaid expenses and other — 30.7 0.3 75.0 — 106.0 Total current assets — 1,975.3 406.3 863.4 (671.5 ) 2,573.5 Property, plant and equipment, net — 209.9 104.8 828.3 — 1,143.0 Goodwill — — 147.8 86.0 — 233.8 Intercompany notes and accounts receivable — 341.6 243.9 — (585.5 ) — Other assets and deferred charges — 666.7 38.4 206.6 — 911.7 Investment in subsidiaries 962.9 1,682.1 — — (2,645.0 ) — Total assets $ 962.9 $ 4,875.6 $ 941.2 $ 1,984.3 $ (3,902.0 ) $ 4,862.0 Liabilities and Stockholders’ Equity Current liabilities Current portion of long-term debt $ — $ — $ — $ 3.4 $ — $ 3.4 Accounts payable — 162.6 43.6 321.7 — 527.9 Intercompany payables — 346.2 159.8 165.5 (671.5 ) — Accrued expenses and other — 113.6 4.5 123.3 — 241.4 Total current liabilities — 622.4 207.9 613.9 (671.5 ) 772.7 Intercompany notes and accounts payable 327.1 17.3 2.0 239.1 (585.5 ) — Long-term debt, net — 2,520.1 4.0 57.4 — 2,581.5 Investment in subsidiaries obligation — — 109.9 — (109.9 ) — Other long-term liabilities — 752.9 0.7 118.4 — 872.0 Total liabilities 327.1 3,912.7 324.5 1,028.8 (1,366.9 ) 4,226.2 Total stockholders’ equity 635.8 962.9 616.7 955.5 (2,535.1 ) 635.8 Total liabilities and stockholders’ equity $ 962.9 $ 4,875.6 $ 941.2 $ 1,984.3 $ (3,902.0 ) $ 4,862.0 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated December 31, 2016 Assets Current assets Cash and cash equivalents $ — $ 84.3 $ 1.6 $ 395.3 $ — $ 481.2 Accounts receivable, net — 126.7 21.9 411.4 — 560.0 Intercompany receivables — 442.6 326.0 9.1 (777.7 ) — Inventories, net — 46.0 29.1 144.4 — 219.5 Prepaid expenses and other — 29.4 0.5 45.9 — 75.8 Total current assets — 729.0 379.1 1,006.1 (777.7 ) 1,336.5 Property, plant and equipment, net — 213.7 102.9 777.1 — 1,093.7 Goodwill — — 147.8 6.2 — 154.0 Intercompany notes and accounts receivable — 343.9 242.2 — (586.1 ) — Other assets and deferred charges — 662.6 37.1 164.2 — 863.9 Investment in subsidiaries 851.8 1,559.0 — — (2,410.8 ) — Total assets $ 851.8 $ 3,508.2 $ 909.1 $ 1,953.6 $ (3,774.6 ) $ 3,448.1 Liabilities and Stockholders’ Equity Current liabilities Current portion of long-term debt $ — $ — $ — $ 3.3 $ — $ 3.3 Accounts payable — 80.6 35.8 265.9 — 382.3 Intercompany payables — 324.8 153.4 299.5 (777.7 ) — Accrued expenses and other — 142.2 4.3 119.4 — 265.9 Total current liabilities — 547.6 193.5 688.1 (777.7 ) 651.5 Intercompany notes and accounts payable 321.8 14.6 7.5 242.2 (586.1 ) — Long-term debt, net — 1,339.7 4.1 57.1 — 1,400.9 Investment in subsidiaries obligation — — 124.7 — (124.7 ) — Other long-term liabilities — 754.5 0.6 110.6 — 865.7 Total liabilities 321.8 2,656.4 330.4 1,098.0 (1,488.5 ) 2,918.1 Total stockholders’ equity 530.0 851.8 578.7 855.6 (2,286.1 ) 530.0 Total liabilities and stockholders’ equity $ 851.8 $ 3,508.2 $ 909.1 $ 1,953.6 $ (3,774.6 ) $ 3,448.1 Condensed Consolidating Statements of Cash Flows Three Months Ended March 31, (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2017 Net cash provided by (used in) operating activities $ — $ 161.8 $ 5.3 $ (104.8 ) $ — $ 62.3 Investing activities Purchases of property, plant and equipment — (11.6 ) (5.2 ) (18.1 ) — (34.9 ) Proceeds from sale of property, plant and equipment — 0.2 — 0.6 — 0.8 Purchase buyouts of leased equipment — (2.3 ) — — — (2.3 ) Proceeds from sale of business, net — 7.5 (1.6 ) — — 5.9 Acquisition of business, net — — — (144.1 ) — (144.1 ) Net cash used in investing activities — (6.2 ) (6.8 ) (161.6 ) — (174.6 ) Financing activities Net debt activity — 1,199.8 (0.1 ) (0.5 ) — 1,199.2 Debt issuance costs — (21.2 ) — — — (21.2 ) Purchase of treasury stock (5.2 ) — — — — (5.2 ) Intercompany activity 5.2 (5.2 ) — — — — Net cash provided by (used in) financing activities — 1,173.4 (0.1 ) (0.5 ) — 1,172.8 Effect of exchange rate changes on cash — — — 1.7 — 1.7 Net increase (decrease) in cash and cash equivalents — 1,329.0 (1.6 ) (265.2 ) — 1,062.2 Cash and cash equivalents at beginning of period — 84.3 1.6 395.3 — 481.2 Cash and cash equivalents at end of period $ — $ 1,413.3 $ — $ 130.1 $ — $ 1,543.4 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2016 Net cash provided by (used in) operating activities $ — $ 66.8 $ 5.1 $ (45.7 ) $ — $ 26.2 Investing activities Purchases of property, plant and equipment — (7.9 ) (5.2 ) (37.5 ) — (50.6 ) Proceeds from sale of property, plant and equipment — — 0.2 0.4 — 0.6 Net cash used in investing activities — (7.9 ) (5.0 ) (37.1 ) — (50.0 ) Financing activities Net debt activity — (0.2 ) (0.1 ) 4.9 — 4.6 Purchase of treasury stock (3.5 ) — — — — (3.5 ) Intercompany activity 3.5 (3.5 ) — — — — Net cash provided by (used in) financing activities — (3.7 ) (0.1 ) 4.9 — 1.1 Effect of exchange rate changes on cash — — — 2.2 — 2.2 Net increase (decrease) in cash and cash equivalents — 55.2 — (75.7 ) — (20.5 ) Cash and cash equivalents at beginning of period — 52.0 — 230.5 — 282.5 Cash and cash equivalents at end of period $ — $ 107.2 $ — $ 154.8 $ — $ 262.0

Organization and Basis of Pre21

Organization and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
New Accounting Pronouncements, Policy [Policy Text Block]	Effect of New Accounting Standards Accounting Standards Update 2017-07 On March 10, 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2017-07 - Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost . The amendments in this update require that an employer disaggregate the service cost component from the other components of defined benefit pension cost and postretirement benefit cost (net benefit cost). The amendments also provide explicit guidance on how to present the service cost component and the other components of net benefit cost in the income statement and allow only the service cost component of net benefit cost to be eligible for capitalization. This guidance becomes effective at the beginning of our 2018 fiscal year, however early adoption is permitted. The guidance requires a retrospective transition method for the income statement classification of the net benefit cost components and a prospective transition method for the capitalization of the service cost component in assets. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2017-04 On January 26, 2017, the FASB issued ASU 2017-04 - Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The amendments in this update modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. An entity no longer will determine goodwill impairment by calculating the implied fair value of goodwill by assigning the fair value of a reporting unit to all of its assets and liabilities as if that reporting unit had been acquired in a business combination, or what is referred to under existing guidance as "Step 2." Instead, under the amendments in this update, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. Additionally, an entity should consider income tax effects from any tax deductible goodwill on the carrying amount of the reporting unit when measuring the goodwill impairment loss, if applicable. This guidance becomes effective at the beginning of our 2020 fiscal year, however early adoption is permitted. The guidance requires a prospective transition method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2016-16 On October 24, 2016, the FASB issued ASU 2016-16 - Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory . Existing income tax guidance prohibits the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset has been sold to an outside party. This existing guidance is deemed an exception to the principle of comprehensive recognition of current and deferred income taxes under GAAP. Due to the limited authoritative guidance about this exception, diversity in practice exists. ASU 2016-16 eliminates this exception for intra-entity transfers of assets other than inventory and requires that entities recognize the income tax consequences when the transfers occur. This guidance becomes effective at the beginning of our 2018 fiscal year, however early adoption is permitted. The guidance requires a modified retrospective transition method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2016-02 On February 25, 2016, the FASB issued ASU 2016-02 - Leases (Topic 842) , which supersedes the existing lease accounting guidance and establishes new criteria for recognizing lease assets and liabilities. The most significant impact of the update, to AAM, is that a lessee will be required to recognize a "right-of-use" asset and lease liability for operating lease agreements that were not previously included on the balance sheet under the existing lease guidance. A lessee will be permitted to make a policy election, excluding recognition of the right-of-use asset and associated liability for lease terms of 12 months or less. Expense recognition in the statement of income along with cash flow statement classification for both financing (capital) and operating leases under the new standard will not be significantly changed from existing lease guidance. This guidance becomes effective for AAM at the beginning of our 2019 fiscal year and requires transition under a modified retrospective method. We are currently assessing the impact that this standard will have on our consolidated financial statements. Accounting Standards Update 2014-09 In 2014, the FASB issued ASU 2014-09 - Revenue from Contracts with Customers (Topic 606) , and has subsequently issued ASUs 2015-14 - Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date , 2016-08 - Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross Versus Net) , 2016-10 - Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing , 2016-12 - Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients , and 2016-20 - Revenue from Contracts with Customers (Topic 606): Technical Corrections and Improvements to Topic 606 (collectively, the Revenue Recognition ASUs). The Revenue Recognition ASUs outline a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersede most current revenue recognition guidance, including industry-specific guidance. The guidance is based on the principle that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to fulfill a contract. This guidance is effective for AAM beginning on January 1, 2018 and entities have the option of using either a full retrospective or a modified retrospective approach for the adoption of the new standard. We are evaluating whether we will adopt this guidance using the full retrospective or modified retrospective approach. We are concluding the assessment phase of implementing this guidance. We have evaluated each of the five steps in the new revenue recognition model, which are as follows: 1) Identify the contract with the customer; 2) Identify the performance obligations in the contract; 3) Determine the transaction price; 4) Allocate the transaction price to the performance obligations; and 5) Recognize revenue when (or as) performance obligations are satisfied. Our preliminary conclusion is that the determination of what constitutes a contract with our customers (step 1), our performance obligations under the contract (step 2), and the determination and allocation of the transaction price (steps 3 and 4) under the new revenue recognition model will not result in significant changes in comparison to the current revenue recognition guidance. With regard to recognizing revenue when (or as) a performance obligation is satisfied (step 5), we are thoroughly reviewing the language in our contracts with each customer to determine whether the customer obtains control of the goods at a point in time or over time. Under current revenue recognition guidance, we recognize revenue when products are shipped to our customers and title transfers under standard commercial terms or when realizable in accordance with our commercial agreements. Topic 606 provides certain criteria that, if met, require companies to recognize revenue as the product is produced (over time) instead of at a point of time (i.e. upon shipment). We are evaluating our contracts, including MPG contracts, in the context of the criteria for recognizing revenue over time. If we conclude that we meet the criteria for recognizing revenue over time, our timing of revenue recognition would be accelerated. We have initiated the assessment phase of evaluating the impact of Topic 606 on MPG's contracts with customers and are assessing the overall impact that the acquisition of MPG will have on our recognition of revenue. There are also certain considerations related to internal control over financial reporting that are associated with implementing the new guidance under Topic 606. We are currently evaluating our control framework for revenue recognition and identifying any changes that may need to be made in response to the new guidance. Disclosure requirements under the new guidance in Topic 606 have been significantly expanded in comparison to the disclosure requirements under the current guidance. Designing and implementing the appropriate controls over gathering and reporting the information required under Topic 606 is currently in process.
Authorized Share Repurchase Program [Policy Text Block]	Share Repurchase Program In 2016, AAM's Board of Directors authorized a share repurchase program of up to $100 million of AAM's common shares through December 31, 2018 as part of AAM's overall capital allocation strategy. The repurchase of shares may be made in the open market or in privately negotiated transactions and will be funded through available cash balances and cash flow from operations. The timing and amount of any share repurchases will be determined based on market and economic conditions, share price, alternative uses of capital and other factors. Approximately $1.5 million of shares have been repurchased under the authorized share repurchase program, leaving approximately $98.5 million available for repurchase. There were no repurchases under the program in the first quarter of 2017.

Restructuring and Acquisition22

Restructuring and Acquisition-Related Costs (Tables)	3 Months Ended
	Mar. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs [Table Text Block]	Severance Charges Implementation Costs Total (in millions) Accrual as of December 31, 2016 $ 0.6 $ 9.2 $ 9.8 Charges 1.2 5.6 6.8 Cash utilization (1.1 ) (1.5 ) (2.6 ) Non-cash utilization — — — Accrual adjustments — — — Accrual as of March 31, 2017 $ 0.7 $ 13.3 $ 14.0
Business Combination, Separately Recognized Transactions [Table Text Block]	Acquisition-Related Costs Integration Expenses Total (in millions) Charges $ 3.3 $ 5.9 $ 9.2 Total restructuring and acquisition-related charges $ 16.0

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2017
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	On March 1, 2017, AAM completed the acquisition of 100% of USM Mexico, a former subsidiary of U.S. Manufacturing Corporation (USM). The purchase price was funded entirely with available cash and the acquisition was accounted for under the acquisition method with the purchase price allocated to the identifiable assets and liabilities of the acquired company based on the respective fair values of the assets and liabilities. USM Mexico includes USM's operations in Guanajuato, Mexico, which has historically been one of the largest suppliers to AAM's Guanajuato Manufacturing Complex. This acquisition allows AAM to vertically integrate the supply chain and helps ensure continuity of supply for certain parts to our largest manufacturing facility. The following represents the estimated fair value of the assets acquired and liabilities assumed resulting from the acquisition, as well as the calculation of goodwill: (in millions) Contractual purchase price $ 162.5 Adjustments to contractual purchase price for capital equipment 4.9 Adjustment to contractual purchase price for settlement of existing accounts payable balance (22.8 ) Cash acquired (0.5 ) Adjusted purchase price, net of cash acquired $ 144.1 Accounts receivable 1.1 Inventories 4.8 Prepaid expenses and other 2.4 Property, plant and equipment 39.1 Intangible assets 31.7 Total assets acquired $ 79.1 Accounts payable 10.8 Accrued expenses and other 2.7 Deferred income tax liabilities 1.2 Net assets acquired $ 64.4 Goodwill $ 79.7
Schedule of Goodwill [Table Text Block]	Goodwill The following table provides a reconciliation of changes in goodwill for the three months ended March 31, 2017: March 31, 2017 (in millions) Beginning balance $ 154.0 Acquisition of USM Mexico 79.7 Foreign currency translation 0.1 Ending balance $ 233.8
Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]	Intangible Assets As a result of the acquisition of USM Mexico, AAM identified and recognized certain intangible assets that are subject to amortization. The weighted-average amortization period for all intangible assets recognized as a result of the acquisition of USM Mexico is 13 years. The following table provides a breakout of the major intangible assets acquired by class: March 31, 2017 (in millions) Technology $ 29.5 Customer platforms 2.2 Total $ 31.7
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following table provides a reconciliation of the gross carrying amount and associated accumulated amortization for AAM's total intangible assets, which are all subject to amortization: March 31, December 31, 2017 2016 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount (in millions) Capitalized computer software $ 33.1 $ (9.9 ) $ 23.2 $ 31.7 $ (8.5 ) $ 23.2 e-AAM in-process research & development 5.4 — 5.4 5.3 — 5.3 Technology 29.5 (0.2 ) 29.3 — — — Customer platforms 2.2 — 2.2 — — — Total $ 70.2 $ (10.1 ) $ 60.1 $ 37.0 $ (8.5 ) $ 28.5

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory, Current [Table Text Block]	Inventories consist of the following: March 31, 2017 December 31, 2016 (in millions) Raw materials and work-in-progress $ 220.4 $ 212.7 Finished goods 28.9 33.8 Gross inventories 249.3 246.5 Inventory valuation reserves (27.7 ) (27.0 ) Inventories, net $ 221.6 $ 219.5

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	Long-term debt consists of the following: March 31, 2017 December 31, 2016 (in millions) Existing Revolving Credit Facility $ — $ — 7.75% Notes due 2019 200.0 200.0 6.625% Notes due 2022 550.0 550.0 6.50% Notes due 2027 500.0 — 6.25% Notes due 2025 700.0 — 6.25% Notes due 2021 400.0 400.0 5.125% Notes due 2019 200.0 200.0 Foreign credit facilities 60.9 60.4 Capital lease obligations 5.4 5.5 Total debt 2,616.3 1,415.9 Less: Current portion of long-term debt 3.4 3.3 Long-term debt 2,612.9 1,412.6 Less: Debt issuance costs 31.4 11.7 Long-term debt, net $ 2,581.5 $ 1,400.9

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The estimated fair value of our financial assets and liabilities that are recognized at fair value on a recurring basis, using available market information and other observable data, are as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Input (in millions) Balance Sheet Classification Cash equivalents $ 1,388.9 $ 1,388.9 $ 187.2 $ 187.2 Level 1 Currency forward contracts - Prepaid expenses and other Cash flow hedges 1.0 1.0 — — Level 2 Nondesignated currency forward contracts 3.0 3.0 — — Level 2 Currency forward contracts - Other assets and deferred charges Cash flow hedges 0.7 0.7 — — Level 2 Currency forward contracts - Accrued expenses and other Cash flow hedges 7.0 7.0 12.3 12.3 Level 2 Nondesignated currency forward contracts — — 1.4 1.4 Level 2 Currency forward contracts - Postretirement benefits and other long-term liabilities Cash flow hedges 2.9 2.9 11.4 11.4 Level 2
Fair Value, Financial Instruments not Carried at Fair Value [Table Text Block]	We estimated the fair value of the amounts outstanding on our debt using available market information and other observable data, to be as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Input (in millions) Existing Revolving Credit Facility $ — $ — $ — $ — Level 2 7.75% Notes due 2019 200.0 220.3 200.0 221.0 Level 2 6.625% Notes due 2022 550.0 564.5 550.0 566.1 Level 2 6.50% Notes due 2027 500.0 500.2 — — Level 2 6.25% Notes due 2025 700.0 695.2 — — Level 2 6.25% Notes due 2021 400.0 410.0 400.0 412.0 Level 2 5.125% Notes due 2019 200.0 202.0 200.0 201.7 Level 2

Derivatives (Tables)

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	The following table summarizes the reclassification of pre-tax derivative losses into net income from accumulated other comprehensive loss for those derivative instruments designated as cash flow hedges under Accounting Standards Codification 815 - Derivatives and Hedging (ASC 815): Loss Reclassified During Loss Expected to Location of Loss Three Months Ended be Reclassified Reclassified into March 31, During the Net Income 2017 2016 Next 12 Months (in millions) Currency forward contracts Cost of Goods Sold $ (2.8 ) $ (2.0 ) $ (6.0 ) The following table summarizes the amount and location of gains (losses) recognized in the Condensed Consolidated Statements of Income for those derivative instruments not designated as hedging instruments under ASC 815: Gain (Loss) Recognized During Location of Gain (Loss) Three Months Ended Recognized in March 31, Net Income 2017 2016 (in millions) Currency forward contracts Cost of Goods Sold $ 3.5 $ (0.5 ) Currency forward contracts Other Income, Net — (0.7 )

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of Net Benefit (Credits) Costs [Table Text Block]	The components of net periodic benefit cost (credit) are as follows: Pension Benefits Three Months Ended March 31, 2017 2016 (in millions) Service cost $ 0.8 $ 0.7 Interest cost 6.8 7.3 Expected asset return (10.5 ) (10.7 ) Amortized loss 1.7 1.4 Net periodic benefit credit $ (1.2 ) $ (1.3 ) Other Postretirement Benefits Three Months Ended March 31, 2017 2016 (in millions) Service cost $ 0.1 $ 0.1 Interest cost 3.3 3.5 Amortized loss 0.2 0.1 Amortized prior service credit (0.7 ) (0.7 ) Net periodic benefit cost $ 2.9 $ 3.0

Product Warranties (Tables)

Product Warranties (Tables)	3 Months Ended
	Mar. 31, 2017
Product Warranties Disclosures [Abstract]
Schedule of Product Warranty Liability [Table Text Block]	The following table provides a reconciliation of changes in the product warranty liability: Three Months Ended March 31, 2017 2016 (in millions) Beginning balance $ 42.9 $ 36.6 Accruals 5.5 3.9 Payments (0.9 ) (0.5 ) Adjustment to prior period accruals (0.2 ) (3.1 ) Foreign currency translation 0.2 0.1 Ending balance $ 47.5 $ 37.0

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of our basic and diluted EPS available to shareholders of common stock (excluding participating securities): Three Months Ended March 31, 2017 2016 (in millions, except per share data) Numerator Net income $ 78.4 $ 61.1 Less: Net income attributable to participating securities (1.9 ) (1.4 ) Net income attributable to common shareholders - Basic and Dilutive $ 76.5 $ 59.7 Denominators Basic common shares outstanding - Weighted-average shares outstanding 78.5 77.9 Less: Participating securities (1.9 ) (1.7 ) Weighted-average common shares outstanding 76.6 76.2 Effect of dilutive securities - Dilutive stock-based compensation 0.4 0.3 Diluted shares outstanding - Adjusted weighted-average shares after assumed conversions 77.0 76.5 Basic EPS $ 1.00 $ 0.78 Diluted EPS $ 0.99 $ 0.78 Certain exercisable stock options were excluded from the computations of diluted EPS because the exercise price of these options was greater than the average period market prices. There were no stock options excluded from the calculation of diluted EPS at March 31, 2017. The number of stock options outstanding, which were not included in the calculation of diluted EPS, was 0.2 million , with an exercise price of $26.02 , at March 31, 2016 .

Reclassifications out of Accu31

Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2017
Reclassifications out of Accumulated Other Comprehensive Income (Loss) [Abstract]
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	Reclassification adjustments and other activity impacting accumulated other comprehensive income (loss) during the three months ended March 31, 2017 and March 31, 2016 are as follows (in millions) : Defined Benefit Plans Foreign Currency Translation Adjustments Unrecognized Loss on Cash Flow Hedges Total Balance at December 31, 2016 $ (243.5 ) $ (122.4 ) $ (23.7 ) $ (389.6 ) Other comprehensive income (loss) before reclassifications (1.7 ) 11.9 12.7 22.9 Income tax effect of other comprehensive income (loss) before reclassifications 0.6 — — 0.6 Amounts reclassified from accumulated other comprehensive loss 1.2 (a) — 2.8 (b) 4.0 Income tax benefit reclassified into net income (0.4 ) — — (0.4 ) Net current period other comprehensive income (loss) (0.3 ) 11.9 15.5 27.1 Balance at March 31, 2017 $ (243.8 ) $ (110.5 ) $ (8.2 ) $ (362.5 ) Defined Benefit Plans Foreign Currency Translation Adjustments Unrecognized Loss on Cash Flow Hedges Total Balance at December 31, 2015 $ (223.9 ) $ (119.2 ) $ (13.4 ) $ (356.5 ) Other comprehensive income before reclassifications 5.7 15.0 1.4 22.1 Income tax effect of other comprehensive income before reclassifications (2.0 ) — — (2.0 ) Amounts reclassified from accumulated other comprehensive loss 0.8 (a) — 2.0 (b) 2.8 Income tax benefit reclassified into net income (0.3 ) — — (0.3 ) Net current period other comprehensive income 4.2 15.0 3.4 22.6 Balance at March 31, 2016 $ (219.7 ) $ (104.2 ) $ (10.0 ) $ (333.9 ) (a) The amount reclassified from AOCI included $1.4 million in cost of goods sold (COGS) and $(0.2) million in selling, general & administrative expenses (SG&A) for the three months ended March 31, 2017 and $1.1 million in COGS and $(0.3) million in SG&A for the three months ended March 31, 2016. (b) The amounts reclassified from AOCI are included in COGS.

Supplemental Guarantor Conden32

Supplemental Guarantor Condensed Consolidating Financial Statements (Tables)	3 Months Ended
	Mar. 31, 2017
Supplemental Guarantor Condensed Consolidating Financial Statements [Abstract]
Supplemental Guarantor Consolidating Income Statement [Table Text Block]	Condensed Consolidating Statements of Income Three Months Ended March 31, (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2017 Net sales External $ — $ 296.6 $ 50.1 $ 703.2 $ — $ 1,049.9 Intercompany — 0.3 66.7 4.9 (71.9 ) — Total net sales — 296.9 116.8 708.1 (71.9 ) 1,049.9 Cost of goods sold — 277.2 94.9 539.0 (71.9 ) 839.2 Gross profit — 19.7 21.9 169.1 — 210.7 Selling, general and administrative expenses — 73.8 — 9.0 — 82.8 Restructuring and acquisition-related costs — 15.3 — 0.7 — 16.0 Operating income (loss) — (69.4 ) 21.9 159.4 — 111.9 Non-operating income (expense), net — (26.2 ) 2.4 (2.2 ) — (26.0 ) Income (loss) before income taxes — (95.6 ) 24.3 157.2 — 85.9 Income tax expense (benefit) — (2.8 ) 0.1 10.2 — 7.5 Earnings (loss) from equity in subsidiaries 78.4 91.6 (0.6 ) — (169.4 ) — Net income (loss) before royalties 78.4 (1.2 ) 23.6 147.0 (169.4 ) 78.4 Royalties — 79.6 — (79.6 ) — — Net income after royalties 78.4 78.4 23.6 67.4 (169.4 ) 78.4 Other comprehensive income, net of tax 27.1 27.1 10.5 26.4 (64.0 ) 27.1 Comprehensive income $ 105.5 $ 105.5 $ 34.1 $ 93.8 $ (233.4 ) $ 105.5 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2016 Net sales External $ — $ 283.2 $ 54.8 $ 631.2 $ — $ 969.2 Intercompany — 1.6 59.7 3.7 (65.0 ) — Total net sales — 284.8 114.5 634.9 (65.0 ) 969.2 Cost of goods sold — 276.3 92.5 491.4 (65.0 ) 795.2 Gross profit — 8.5 22.0 143.5 — 174.0 Selling, general and administrative expenses — 67.5 — 8.1 — 75.6 Operating income (loss) — (59.0 ) 22.0 135.4 — 98.4 Non-operating income (expense), net — (24.3 ) 3.0 (0.7 ) — (22.0 ) Income (loss) before income taxes — (83.3 ) 25.0 134.7 — 76.4 Income tax expense — 7.8 0.1 7.4 — 15.3 Earnings (loss) from equity in subsidiaries 61.1 92.9 (9.6 ) — (144.4 ) — Net income before royalties 61.1 1.8 15.3 127.3 (144.4 ) 61.1 Royalties — 59.3 — (59.3 ) — — Net income after royalties 61.1 61.1 15.3 68.0 (144.4 ) 61.1 Other comprehensive income, net of tax 22.6 22.6 15.7 19.8 (58.1 ) 22.6 Comprehensive income $ 83.7 $ 83.7 $ 31.0 $ 87.8 $ (202.5 ) $ 83.7
Supplemental Guarantor Consolidating Balance Sheet [Table Text Block]	Condensed Consolidating Balance Sheets (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated March 31, 2017 Assets Current assets Cash and cash equivalents $ — $ 1,413.3 $ — $ 130.1 $ — $ 1,543.4 Accounts receivable, net — 175.3 23.9 503.3 — 702.5 Intercompany receivables — 312.0 350.5 9.0 (671.5 ) — Inventories, net — 44.0 31.6 146.0 — 221.6 Prepaid expenses and other — 30.7 0.3 75.0 — 106.0 Total current assets — 1,975.3 406.3 863.4 (671.5 ) 2,573.5 Property, plant and equipment, net — 209.9 104.8 828.3 — 1,143.0 Goodwill — — 147.8 86.0 — 233.8 Intercompany notes and accounts receivable — 341.6 243.9 — (585.5 ) — Other assets and deferred charges — 666.7 38.4 206.6 — 911.7 Investment in subsidiaries 962.9 1,682.1 — — (2,645.0 ) — Total assets $ 962.9 $ 4,875.6 $ 941.2 $ 1,984.3 $ (3,902.0 ) $ 4,862.0 Liabilities and Stockholders’ Equity Current liabilities Current portion of long-term debt $ — $ — $ — $ 3.4 $ — $ 3.4 Accounts payable — 162.6 43.6 321.7 — 527.9 Intercompany payables — 346.2 159.8 165.5 (671.5 ) — Accrued expenses and other — 113.6 4.5 123.3 — 241.4 Total current liabilities — 622.4 207.9 613.9 (671.5 ) 772.7 Intercompany notes and accounts payable 327.1 17.3 2.0 239.1 (585.5 ) — Long-term debt, net — 2,520.1 4.0 57.4 — 2,581.5 Investment in subsidiaries obligation — — 109.9 — (109.9 ) — Other long-term liabilities — 752.9 0.7 118.4 — 872.0 Total liabilities 327.1 3,912.7 324.5 1,028.8 (1,366.9 ) 4,226.2 Total stockholders’ equity 635.8 962.9 616.7 955.5 (2,535.1 ) 635.8 Total liabilities and stockholders’ equity $ 962.9 $ 4,875.6 $ 941.2 $ 1,984.3 $ (3,902.0 ) $ 4,862.0 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated December 31, 2016 Assets Current assets Cash and cash equivalents $ — $ 84.3 $ 1.6 $ 395.3 $ — $ 481.2 Accounts receivable, net — 126.7 21.9 411.4 — 560.0 Intercompany receivables — 442.6 326.0 9.1 (777.7 ) — Inventories, net — 46.0 29.1 144.4 — 219.5 Prepaid expenses and other — 29.4 0.5 45.9 — 75.8 Total current assets — 729.0 379.1 1,006.1 (777.7 ) 1,336.5 Property, plant and equipment, net — 213.7 102.9 777.1 — 1,093.7 Goodwill — — 147.8 6.2 — 154.0 Intercompany notes and accounts receivable — 343.9 242.2 — (586.1 ) — Other assets and deferred charges — 662.6 37.1 164.2 — 863.9 Investment in subsidiaries 851.8 1,559.0 — — (2,410.8 ) — Total assets $ 851.8 $ 3,508.2 $ 909.1 $ 1,953.6 $ (3,774.6 ) $ 3,448.1 Liabilities and Stockholders’ Equity Current liabilities Current portion of long-term debt $ — $ — $ — $ 3.3 $ — $ 3.3 Accounts payable — 80.6 35.8 265.9 — 382.3 Intercompany payables — 324.8 153.4 299.5 (777.7 ) — Accrued expenses and other — 142.2 4.3 119.4 — 265.9 Total current liabilities — 547.6 193.5 688.1 (777.7 ) 651.5 Intercompany notes and accounts payable 321.8 14.6 7.5 242.2 (586.1 ) — Long-term debt, net — 1,339.7 4.1 57.1 — 1,400.9 Investment in subsidiaries obligation — — 124.7 — (124.7 ) — Other long-term liabilities — 754.5 0.6 110.6 — 865.7 Total liabilities 321.8 2,656.4 330.4 1,098.0 (1,488.5 ) 2,918.1 Total stockholders’ equity 530.0 851.8 578.7 855.6 (2,286.1 ) 530.0 Total liabilities and stockholders’ equity $ 851.8 $ 3,508.2 $ 909.1 $ 1,953.6 $ (3,774.6 ) $ 3,448.1
Supplemental Guarantor Consolidating Statement of Cash Flows [Table Text Block]	Condensed Consolidating Statements of Cash Flows Three Months Ended March 31, (in millions) Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2017 Net cash provided by (used in) operating activities $ — $ 161.8 $ 5.3 $ (104.8 ) $ — $ 62.3 Investing activities Purchases of property, plant and equipment — (11.6 ) (5.2 ) (18.1 ) — (34.9 ) Proceeds from sale of property, plant and equipment — 0.2 — 0.6 — 0.8 Purchase buyouts of leased equipment — (2.3 ) — — — (2.3 ) Proceeds from sale of business, net — 7.5 (1.6 ) — — 5.9 Acquisition of business, net — — — (144.1 ) — (144.1 ) Net cash used in investing activities — (6.2 ) (6.8 ) (161.6 ) — (174.6 ) Financing activities Net debt activity — 1,199.8 (0.1 ) (0.5 ) — 1,199.2 Debt issuance costs — (21.2 ) — — — (21.2 ) Purchase of treasury stock (5.2 ) — — — — (5.2 ) Intercompany activity 5.2 (5.2 ) — — — — Net cash provided by (used in) financing activities — 1,173.4 (0.1 ) (0.5 ) — 1,172.8 Effect of exchange rate changes on cash — — — 1.7 — 1.7 Net increase (decrease) in cash and cash equivalents — 1,329.0 (1.6 ) (265.2 ) — 1,062.2 Cash and cash equivalents at beginning of period — 84.3 1.6 395.3 — 481.2 Cash and cash equivalents at end of period $ — $ 1,413.3 $ — $ 130.1 $ — $ 1,543.4 Holdings AAM Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Elims Consolidated 2016 Net cash provided by (used in) operating activities $ — $ 66.8 $ 5.1 $ (45.7 ) $ — $ 26.2 Investing activities Purchases of property, plant and equipment — (7.9 ) (5.2 ) (37.5 ) — (50.6 ) Proceeds from sale of property, plant and equipment — — 0.2 0.4 — 0.6 Net cash used in investing activities — (7.9 ) (5.0 ) (37.1 ) — (50.0 ) Financing activities Net debt activity — (0.2 ) (0.1 ) 4.9 — 4.6 Purchase of treasury stock (3.5 ) — — — — (3.5 ) Intercompany activity 3.5 (3.5 ) — — — — Net cash provided by (used in) financing activities — (3.7 ) (0.1 ) 4.9 — 1.1 Effect of exchange rate changes on cash — — — 2.2 — 2.2 Net increase (decrease) in cash and cash equivalents — 55.2 — (75.7 ) — (20.5 ) Cash and cash equivalents at beginning of period — 52.0 — 230.5 — 282.5 Cash and cash equivalents at end of period $ — $ 107.2 $ — $ 154.8 $ — $ 262.0

Share Repurchase Program (Detai

Share Repurchase Program (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2016	Mar. 31, 2017	May 05, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Stock Repurchase Program, Authorized Amount			$ 100
Treasury Stock, Value, Acquired, Cost Method	$ 1.5
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 98.5

Restructuring and Acquisition34

Restructuring and Acquisition-Related Costs (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Mar. 31, 2017
Restructuring Reserve [Roll Forward]
Restructuring Reserve	$ 9.8
Restructuring Charges	6.8
Payments for Restructuring	(2.6)
Restructuring Reserve, Settled without Cash	0
Restructuring Reserve, Accrual Adjustment	0
Restructuring Reserve	14	$ 14
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	9.2
Restructuring Charges	5.6	15.8
Payments for Restructuring	(1.5)
Restructuring Reserve, Settled without Cash	0
Restructuring Reserve, Accrual Adjustment	0
Restructuring Reserve	13.3	13.3
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	0.6
Restructuring Charges	1.2	1.8
Payments for Restructuring	(1.1)
Restructuring Reserve, Settled without Cash	0
Restructuring Reserve, Accrual Adjustment	0
Restructuring Reserve	$ 0.7	$ 0.7

Restructuring and Acquisition35

Restructuring and Acquisition-Related Costs Restructuring Reserve Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2017USD ($)	Mar. 31, 2017USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 6.8
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	1.2	$ 1.8
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	5.6	15.8
Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining	20	20
Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost Remaining	$ 15	$ 15

Restructuring and Acquisition36

Restructuring and Acquisition-Related Costs Business Combinations, Separately Recognized Transactions Table (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Restructuring and Related Activities [Abstract]
Business Combination, Acquisition Related Costs	$ 3.3
Business Combination, Integration Related Costs	5.9
Business Combination, Acquisition & Integration Related Costs	9.2
Restructuring and acquisition-related costs	$ 16	$ 0

USM Acquisition Table (Details)

USM Acquisition Table (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 01, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Adjusted purchase price, net of cash acquired	$ 144.1	$ 0
Goodwill	233.8			$ 154
USM Mexico Manufacturing LLC [Member]
Business Acquisition [Line Items]
Contractual purchase price	162.5
Adjustments to contractual purchase price for capital equipment			$ 4.9
Adjustment to contractual purchase price for settlement of existing accounts payable balance			(22.8)
Cash acquired			(0.5)
Adjusted purchase price, net of cash acquired	$ 144.1
Accounts receivable			1.1
Inventories			4.8
Prepaid expenses and other			2.4
Property, plant and equipment			39.1
Intangible assets			31.7
Total assets acquired			79.1
Accounts payable			10.8
Accrued expenses and other			2.7
Deferred income tax liabilities			1.2
Net assets acquired			64.4
Goodwill			$ 79.7

Business Combinations Acquisiti

Business Combinations Acquisition of MPG Narrative (Details) - USD ($) $ in Millions	Apr. 06, 2017	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Proceeds from Issuance of Long-term Debt		$ 1,209.4	$ 6.2
Metaldyne Performance Group, Inc. [Member]
Business Acquisition [Line Items]
Contractual purchase price		1,500
Proposed Business Acquisition Net Debt to be Assumed by Acquiring Entity		1,700
Noncash or Part Noncash Acquisition, Debt Assumed		1,900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		200
Notes Issued		1,200
Business Acquisition, Pro Forma Revenue		1,800	$ 1,700
6.25% Notes due 2025 [Member] | Metaldyne Performance Group, Inc. [Member]
Business Acquisition [Line Items]
Notes Issued		$ 700
Debt Instrument, Interest Rate, Stated Percentage		6.25%
6.50% Notes due 2027 [Member] | Metaldyne Performance Group, Inc. [Member]
Business Acquisition [Line Items]
Notes Issued		$ 500
Debt Instrument, Interest Rate, Stated Percentage		6.50%
Term Loan A [Member] | Metaldyne Performance Group, Inc. [Member]
Business Acquisition [Line Items]
Proceeds from Issuance of Long-term Debt	$ 100
Term Loan B [Member] | Metaldyne Performance Group, Inc. [Member]
Business Acquisition [Line Items]
Proceeds from Issuance of Long-term Debt	$ 1,550

Business Combinations Goodwill

Business Combinations Goodwill Rollforward (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 154
Acquisition of USM Mexico	79.7
Foreign currency translation	0.1
Ending balance	$ 233.8

Business Combinations Intangibl

Business Combinations Intangibles Acquired Table (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	13 years
USM Mexico Manufacturing LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 31.7
Technology-Based Intangible Assets [Member] | USM Mexico Manufacturing LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	29.5
Customer-Related Intangible Assets [Member] | USM Mexico Manufacturing LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 2.2

Business Combinations Intangi41

Business Combinations Intangible Assets Table (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 70.2	$ 37
Finite-Lived Intangible Assets, Accumulated Amortization	(10.1)	(8.5)
Finite-Lived Intangible Assets, Net	60.1	28.5
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	33.1	31.7
Finite-Lived Intangible Assets, Accumulated Amortization	(9.9)	(8.5)
Finite-Lived Intangible Assets, Net	23.2	23.2
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	5.4	5.3
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Finite-Lived Intangible Assets, Net	5.4	5.3
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	29.5	0
Finite-Lived Intangible Assets, Accumulated Amortization	(0.2)	0
Finite-Lived Intangible Assets, Net	29.3	0
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2.2	0
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Finite-Lived Intangible Assets, Net	$ 2.2	$ 0

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Inventory [Line Items]
Raw materials and work-in-progress	$ 220.4	$ 212.7
Finished goods	28.9	33.8
Gross inventories	249.3	246.5
Inventory valuation reserves	(27.7)	(27)
Inventories, net	$ 221.6	$ 219.5

Schedule of Long-Term Debt (Det

Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 2,616.3	$ 1,415.9
Current portion of long-term debt	3.4	3.3
Long-term debt	2,612.9	1,412.6
Long-term debt, net	2,581.5	1,400.9
Total Debt Instruments excluding Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Unamortized Debt Issuance Expense	31.4	11.7
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	0	0
Unsecured Debt [Member] | 7.75% Notes [Member]
Debt Instrument [Line Items]
Notes payable	$ 200	200
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Unsecured Debt [Member] | 6.625% Notes [Member]
Debt Instrument [Line Items]
Notes payable	$ 550	550
Debt Instrument, Interest Rate, Stated Percentage	6.625%
Unsecured Debt [Member] | 6.50% Notes due 2027 [Member]
Debt Instrument [Line Items]
Notes payable	$ 500	0
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Unsecured Debt [Member] | 6.25% Notes due 2025 [Member]
Debt Instrument [Line Items]
Notes payable	$ 700	0
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Unsecured Debt [Member] | 6.25% Notes Due 2021 [Member]
Debt Instrument [Line Items]
Notes payable	$ 400	400
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Unsecured Debt [Member] | 5.125% Notes [Member]
Debt Instrument [Line Items]
Notes payable	$ 200	200
Debt Instrument, Interest Rate, Stated Percentage	5.125%
Foreign Credit Facilities [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	$ 60.9	60.4
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Capital lease obligations	$ 5.4	$ 5.5

Existing Revolving Credit Facil

Existing Revolving Credit Facility Narrative (Details) - Revolving Credit Facility [Member] $ in Millions	Mar. 31, 2017USD ($)
Long-Term Debt Narrative [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 523.5
Line of Credit Facility, Remaining Borrowing Capacity	507.3
Line of Credit Facility, Standby Letters of Credit Issued Against the Facility	$ 16.2

Long-Term Debt Issuance of New

Long-Term Debt Issuance of New Notes Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Debt Instrument [Line Items]
Payments of Debt Issuance Costs	$ 21.2	$ 0
6.25% Notes Due 2025 & 6.50% Notes Due 2027 [Member]
Debt Instrument [Line Items]
Payments of Debt Issuance Costs	19.6
Metaldyne Performance Group, Inc. [Member]
Debt Instrument [Line Items]
Notes Issued	1,200
Metaldyne Performance Group, Inc. [Member] | 6.25% Notes due 2025 [Member]
Debt Instrument [Line Items]
Notes Issued	$ 700
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Metaldyne Performance Group, Inc. [Member] | 6.50% Notes due 2027 [Member]
Debt Instrument [Line Items]
Notes Issued	$ 500
Debt Instrument, Interest Rate, Stated Percentage	6.50%

Long-Term Debt New Senior Secur

Long-Term Debt New Senior Secured Credit Facilities Narrative (Details) - USD ($) $ in Millions	Apr. 06, 2017	Mar. 31, 2017	Mar. 31, 2016
Debt Instrument [Line Items]
Payments of Debt Issuance Costs		$ 21.2	$ 0
Line of Credit Facility, Interest Rate Description		The Term Loan A Facility and the Revolving Credit Facility will mature on April 6, 2022, and the Term Loan B Facility will mature on April 6, 2024. Borrowings under the New Senior Secured Credit Facilities bear interest at rates based on the applicable Eurodollar rate or alternate base rate, as AAM may elect, in each case plus an applicable margin determined based on AAM’s total net leverage ratio. The alternate base rate is the greatest of (a) the JPMorgan Chase Bank, N.A. prime rate, (b) the Federal Reserve Bank of New York rate plus 0.50% and (c) the adjusted Eurodollar rate plus 1.00%. The applicable margin for Eurodollar-based loans under the New Senior Secured Credit Facilities will be between 1.25% and 2.25% with respect to any loan under the Term Loan A Facility, 2.25% with respect to any loan under the Term Loan B Facility, and between 2.00% and 3.00% with respect to any loan under the Revolving Credit Facility. The applicable margin for loans subject to alternate base rate will be between 0.25% and 1.25% with respect to any loan under the Term Loan A Facility, 1.25% with respect to any loan under the Term Loan B Facility, and between 1.00% and 2.00% with respect to any loan under the Revolving Credit Facility.
Line of Credit Facility, Borrowing Capacity, Description		The Credit Agreement permits AAM, Inc. to incur incremental term loan borrowings and/or increase commitments under the Revolving Credit Facility, subject to certain limitations and the satisfaction of certain conditions, in an aggregate amount not to exceed (i) $600 million, plus (ii) certain voluntary prepayments, plus (iii) additional amounts subject to pro forma compliance with a first lien net leverage ratio for Holdings and its restricted subsidiaries.
Proceeds from Issuance of Long-term Debt		$ 1,209.4	$ 6.2
New Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Payments of Debt Issuance Costs		$ 1.6
Metaldyne Performance Group, Inc. [Member] | Term Loan A [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt	$ 100
Metaldyne Performance Group, Inc. [Member] | Term Loan B [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt	1,550
Metaldyne Performance Group, Inc. [Member] | New Multi-Currency Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 900
Metaldyne Performance Group, Inc. [Member] | 7.375% Notes - MPG [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.375%

Long-Term Debt Other Debt Discl

Long-Term Debt Other Debt Disclosures Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate	6.70%	6.60%
Foreign Credit Facilities [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 60.9	$ 60.4
Debt Instrument, Unused Borrowing Capacity, Amount	$ 91.2

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, at carrying value	$ 1,388.9	$ 187.2
Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents, at fair value	1,388.9	187.2
Designated as Hedging Instrument [Member] | Prepaid expenses and other [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	1	0
Designated as Hedging Instrument [Member] | Prepaid expenses and other [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	1	0
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	0.7	0
Designated as Hedging Instrument [Member] | Other Noncurrent Assets [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	0.7	0
Designated as Hedging Instrument [Member] | Accrued expenses and other [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	7	12.3
Designated as Hedging Instrument [Member] | Accrued expenses and other [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	7	12.3
Designated as Hedging Instrument [Member] | Postretirement benefits and other long-term liabilities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	2.9	11.4
Designated as Hedging Instrument [Member] | Postretirement benefits and other long-term liabilities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	2.9	11.4
Not Designated as Hedging Instrument [Member] | Prepaid expenses and other [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	3	0
Not Designated as Hedging Instrument [Member] | Prepaid expenses and other [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	3	0
Not Designated as Hedging Instrument [Member] | Accrued expenses and other [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	0	1.4
Not Designated as Hedging Instrument [Member] | Accrued expenses and other [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Currency forward contracts	$ 0	$ 1.4

Fair Value of Debt (Details)

Fair Value of Debt (Details) - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Revolving Credit Facility [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of Credit Facility, Amount Outstanding	$ 0	$ 0
Revolving Credit Facility [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Line of Credit Facility, Amount Outstanding	0	0
7.75% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	200	200
7.75% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	220.3	221
6.625% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	550	550
6.625% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	564.5	566.1
6.50% Notes due 2027 [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	500	0
6.50% Notes due 2027 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	500.2	0
6.25% Notes due 2025 [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	700	0
6.25% Notes due 2025 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	695.2	0
6.25% Notes Due 2021 [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	400	400
6.25% Notes Due 2021 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	410	412
5.125% Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	200	200
5.125% Notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes payable	$ 202	$ 201.7

Derivatives Narrative (Details)

Derivatives Narrative (Details) $ in Millions	Mar. 31, 2017USD ($)
Forward Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, Notional Amount	$ 176.3

Schedule of Derivatives (Detail

Schedule of Derivatives (Details) - Forward Contracts [Member] - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2018
Other Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Description of Location of Loss on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments in Financial Statements	Other Income, Net
Derivative Instruments Not Designated as Hedging Instruments, Loss	$ 0	$ (0.7)
Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Description of Location of Loss on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments in Financial Statements	Cost of Goods Sold
Derivative Instruments Not Designated as Hedging Instruments, Loss	$ 3.5	(0.5)
Cost of Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Income Statement Location Loss Reclassified from Accumulated OCI	Cost of Goods Sold
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ (2.8)	$ (2)
Cost of Sales [Member] | Cash Flow Hedging [Member] | Scenario, Forecast [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Cash flow hedge loss to be reclassified within twelve months			$ (6)

Schedule of Employee Benefit Pl

Schedule of Employee Benefit Plans Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 0.8	$ 0.7
Interest cost	6.8	7.3
Expected asset return	(10.5)	(10.7)
Amortized loss	1.7	1.4
Net periodic benefit credit	(1.2)	(1.3)
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.1	0.1
Interest cost	3.3	3.5
Amortized loss	0.2	0.1
Amortized prior service credit	(0.7)	(0.7)
Net periodic benefit cost	$ 2.9	$ 3

Employee Benefit Plans and Othe

Employee Benefit Plans and Other Postretirement Benefit Plans Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Pension Plan, Liabilities, Noncurrent		$ 111	$ 113.5
Other Postretirement Defined Benefit Plan, Liabilities, Noncurrent		$ 543.6	$ 542.6
Scenario, Forecast [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year	$ 16

Product Warranties (Details)

Product Warranties (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Product Warranty Rollforward
Beginning balance	$ 42.9	$ 36.6
Accruals	5.5	3.9
Payments	(0.9)	(0.5)
Adjustment to prior period accruals	(0.2)	(3.1)
Foreign currency translation	0.2	0.1
Ending balance	$ 47.5	$ 37

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Income tax expense	$ 7.5	$ 15.3
Effective income tax rate, continuing operations	8.70%	20.00%
Unrecognized tax benefit liability, including penalties and accrued interest	$ 38.5		$ 30.7
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		$ 26.1
Metaldyne Performance Group, Inc. [Member]
Notes Issued	1,200
6.25% Notes due 2025 [Member] | Metaldyne Performance Group, Inc. [Member]
Notes Issued	$ 700
Debt Instrument, Interest Rate, Stated Percentage	6.25%
6.50% Notes due 2027 [Member] | Metaldyne Performance Group, Inc. [Member]
Notes Issued	$ 500
Debt Instrument, Interest Rate, Stated Percentage	6.50%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator
Net income	$ 78.4	$ 61.1
Less: Net income attributable to participating securities	(1.9)	(1.4)
Net income attributable to common shareholders - Basic and Dilutive	$ 76.5	$ 59.7
Denominators
Basic - Weighted-average shares outstanding	78.5	77.9
Basic - Less: Participating securities	(1.9)	(1.7)
Basic - Weighted-average common shares outstanding	76.6	76.2
Effect of dilutive securities - dilutive stock-based compensation	0.4	0.3
Diluted - Adjusted weighted-average shares after assumed conversions	77	76.5
Basic EPS	$ 1	$ 0.78
Diluted EPS	$ 0.99	$ 0.78

Earnings Per Share Narrative (D

Earnings Per Share Narrative (Details) shares in Millions	3 Months Ended
	Mar. 31, 2016$ / sharesshares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares	0.2
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnings Per Share, Exercise Prices of Stock Options Excluded from the Calculation of Diluted EPS | $ / shares	$ 26.02

Reclassifications out of Accu58

Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined benefit plans - Beginning balance	$ (243.5)
Defined benefit plans, net current period other comprehensive income (loss)	(0.3)	$ 4.2
Defined benefit plans - Ending balance	(243.8)
Foreign currency translation adjustments - Beginning balance	(122.4)
Foreign currency translation adjustments, net current period other comprehensive income (loss)	11.9	15
Foreign currency translation adjustments - Ending balance	(110.5)
Unrecognized loss on cash flow hedges - Beginning balance	(23.7)
Unrecognized loss on cash flow hedges, net current period other comprehensive income (loss)	15.5	3.4
Unrecognized loss on cash flow hedges - Ending balance	(8.2)
Other comprehensive income	27.1	22.6
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Defined benefit plans - Beginning balance	(243.5)	(223.9)
Defined benefit plans, other comprehensive income (loss), before reclassifications	(1.7)	5.7
Income tax effect of other comprehensive income (loss) before reclassifications	0.6	(2)
Defined benefit plans, amounts reclassified from accumulated other comprehensive loss	1.2	0.8
Income taxes reclassified into net income	(0.4)	(0.3)
Defined benefit plans, net current period other comprehensive income (loss)	(0.3)	4.2
Defined benefit plans - Ending balance	(243.8)	(219.7)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Foreign currency translation adjustments - Beginning balance	(122.4)	(119.2)
Foreign currency translation adjustments, other comprehensive income (loss) arising during period	11.9	15
Foreign currency translation adjustments, amounts reclassified from accumulated other comprehensive loss	0	0
Foreign currency translation adjustments, net current period other comprehensive income (loss)	11.9	15
Foreign currency translation adjustments - Ending balance	(110.5)	(104.2)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member]
Unrecognized loss on cash flow hedges - Beginning balance	(23.7)	(13.4)
Unrecognized loss on cash flow hedges, other comprehensive income (loss) arising during period	12.7	1.4
Unrecognized loss on cash flow hedges, amounts reclassified from accumulated other comprehensive loss	2.8	2
Unrecognized loss on cash flow hedges, net current period other comprehensive income (loss)	15.5	3.4
Unrecognized loss on cash flow hedges - Ending balance	(8.2)	(10)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated other comprehensive income (loss), net of tax - Beginning balance	(389.6)	(356.5)
Other comprehensive income (loss) arising during period, total	22.9	22.1
Other Comprehensive Income (Loss) before Reclassifications, Tax	0.6	(2)
Reclassification from AOCI, Current Period, Tax	4	2.8
Reclassification from AOCI, Current Period, Tax	(0.4)	(0.3)
Other comprehensive income	27.1	22.6
Accumulated other comprehensive income (loss), net of tax - Ending balance	$ (362.5)	$ (333.9)

Reclassifications out of Accu59

Reclassifications out of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cost of Sales [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Defined benefit plans, amounts reclassified from accumulated other comprehensive income (loss)	$ 1.4	$ 1.1
Selling, General and Administrative Expenses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Defined benefit plans, amounts reclassified from accumulated other comprehensive income (loss)	$ (0.2)	$ (0.3)

Supplemental Guarantor Conden60

Supplemental Guarantor Condensed Consolidating Financial Statements Supplemental Guarantor Condensed Consolidating Financial Statements Narrative (Details)	Mar. 31, 2017
Debt Instrument [Line Items]
Ownership in Subsidiary, Percentage	100.00%
Unsecured Debt [Member] | 7.75% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.75%
Unsecured Debt [Member] | 6.625% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%
Unsecured Debt [Member] | 6.50% Notes due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Unsecured Debt [Member] | 6.25% Notes due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Unsecured Debt [Member] | 6.25% Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.25%
Unsecured Debt [Member] | 5.125% Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.125%

Supplemental Guarantor Conden61

Supplemental Guarantor Condensed Consolidating Financial Statements Supplemental Guarantor Condensed Consolidating Statements of Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net sales
External	$ 1,049.9	$ 969.2
Intercompany	0	0
Total net sales	1,049.9	969.2
Cost of goods sold	839.2	795.2
Gross profit	210.7	174
Selling, general and administrative expenses	82.8	75.6
Restructuring and acquisition-related costs	16	0
Operating income (loss)	111.9	98.4
Non-operating income (expense), net	(26)	(22)
Income (loss) before income taxes	85.9	76.4
Income tax expense (benefit)	7.5	15.3
Earnings (loss) from equity in subsidiaries	0	0
Net income (loss) before royalties	78.4	61.1
Royalties	0	0
Net income after royalties	78.4	61.1
Other comprehensive income, net of tax	27.1	22.6
Comprehensive income	105.5	83.7
Holdings [Member]
Net sales
External	0	0
Intercompany	0	0
Total net sales	0	0
Cost of goods sold	0	0
Gross profit	0	0
Selling, general and administrative expenses	0	0
Restructuring and acquisition-related costs	0
Operating income (loss)	0	0
Non-operating income (expense), net	0	0
Income (loss) before income taxes	0	0
Income tax expense (benefit)	0	0
Earnings (loss) from equity in subsidiaries	78.4	61.1
Net income (loss) before royalties	78.4	61.1
Royalties	0	0
Net income after royalties	78.4	61.1
Other comprehensive income, net of tax	27.1	22.6
Comprehensive income	105.5	83.7
AAM Inc. [Member]
Net sales
External	296.6	283.2
Intercompany	0.3	1.6
Total net sales	296.9	284.8
Cost of goods sold	277.2	276.3
Gross profit	19.7	8.5
Selling, general and administrative expenses	73.8	67.5
Restructuring and acquisition-related costs	15.3
Operating income (loss)	(69.4)	(59)
Non-operating income (expense), net	(26.2)	(24.3)
Income (loss) before income taxes	(95.6)	(83.3)
Income tax expense (benefit)	(2.8)	7.8
Earnings (loss) from equity in subsidiaries	91.6	92.9
Net income (loss) before royalties	(1.2)	1.8
Royalties	79.6	59.3
Net income after royalties	78.4	61.1
Other comprehensive income, net of tax	27.1	22.6
Comprehensive income	105.5	83.7
Guarantor Subsidiaries [Member]
Net sales
External	50.1	54.8
Intercompany	66.7	59.7
Total net sales	116.8	114.5
Cost of goods sold	94.9	92.5
Gross profit	21.9	22
Selling, general and administrative expenses	0	0
Restructuring and acquisition-related costs	0
Operating income (loss)	21.9	22
Non-operating income (expense), net	2.4	3
Income (loss) before income taxes	24.3	25
Income tax expense (benefit)	0.1	0.1
Earnings (loss) from equity in subsidiaries	(0.6)	(9.6)
Net income (loss) before royalties	23.6	15.3
Royalties	0	0
Net income after royalties	23.6	15.3
Other comprehensive income, net of tax	10.5	15.7
Comprehensive income	34.1	31
Non-Guarantor Subsidiaries [Member]
Net sales
External	703.2	631.2
Intercompany	4.9	3.7
Total net sales	708.1	634.9
Cost of goods sold	539	491.4
Gross profit	169.1	143.5
Selling, general and administrative expenses	9	8.1
Restructuring and acquisition-related costs	0.7
Operating income (loss)	159.4	135.4
Non-operating income (expense), net	(2.2)	(0.7)
Income (loss) before income taxes	157.2	134.7
Income tax expense (benefit)	10.2	7.4
Earnings (loss) from equity in subsidiaries	0	0
Net income (loss) before royalties	147	127.3
Royalties	(79.6)	(59.3)
Net income after royalties	67.4	68
Other comprehensive income, net of tax	26.4	19.8
Comprehensive income	93.8	87.8
Consolidation, Eliminations [Member]
Net sales
External	0	0
Intercompany	(71.9)	(65)
Total net sales	(71.9)	(65)
Cost of goods sold	(71.9)	(65)
Gross profit	0	0
Selling, general and administrative expenses	0	0
Restructuring and acquisition-related costs	0
Operating income (loss)	0	0
Non-operating income (expense), net	0	0
Income (loss) before income taxes	0	0
Income tax expense (benefit)	0	0
Earnings (loss) from equity in subsidiaries	(169.4)	(144.4)
Net income (loss) before royalties	(169.4)	(144.4)
Royalties	0	0
Net income after royalties	(169.4)	(144.4)
Other comprehensive income, net of tax	(64)	(58.1)
Comprehensive income	$ (233.4)	$ (202.5)

Supplemental Guarantor Conden62

Supplemental Guarantor Condensed Consolidating Financial Statements Supplemental Guarantor Condensed Consolidating Balance Sheets (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 1,543.4	$ 481.2	$ 262	$ 282.5
Accounts receivable, net	702.5	560
Intercompany receivables	0	0
Inventories, net	221.6	219.5
Prepaid expenses and other	106	75.8
Total current assets	2,573.5	1,336.5
Property, plant and equipment, net	1,143	1,093.7
Goodwill	233.8	154
Intercompany notes and accounts receivable	0	0
Other assets and deferred charges	911.7	863.9
Investment in subsidiaries	0	0
Total assets	4,862	3,448.1
Current liabilities
Current portion of long-term debt	3.4	3.3
Accounts payable	527.9	382.3
Intercompany payables	0	0
Accrued expenses and other	241.4	265.9
Total current liabilities	772.7	651.5
Intercompany notes and accounts payable	0	0
Long-term debt, net	2,581.5	1,400.9
Investment in Subsidiaries Obligation	0	0
Other long-term liabilities	872	865.7
Total liabilities	4,226.2	2,918.1
Total stockholders’ equity	635.8	530
Total liabilities and stockholders' equity	4,862	3,448.1
Holdings [Member]
Current assets
Cash and cash equivalents	0	0	0	0
Accounts receivable, net	0	0
Intercompany receivables	0	0
Inventories, net	0	0
Prepaid expenses and other	0	0
Total current assets	0	0
Property, plant and equipment, net	0	0
Goodwill	0	0
Intercompany notes and accounts receivable	0	0
Other assets and deferred charges	0	0
Investment in subsidiaries	962.9	851.8
Total assets	962.9	851.8
Current liabilities
Current portion of long-term debt	0	0
Accounts payable	0	0
Intercompany payables	0	0
Accrued expenses and other	0	0
Total current liabilities	0	0
Intercompany notes and accounts payable	327.1	321.8
Long-term debt, net	0	0
Investment in Subsidiaries Obligation	0	0
Other long-term liabilities	0	0
Total liabilities	327.1	321.8
Total stockholders’ equity	635.8	530
Total liabilities and stockholders' equity	962.9	851.8
AAM Inc. [Member]
Current assets
Cash and cash equivalents	1,413.3	84.3	107.2	52
Accounts receivable, net	175.3	126.7
Intercompany receivables	312	442.6
Inventories, net	44	46
Prepaid expenses and other	30.7	29.4
Total current assets	1,975.3	729
Property, plant and equipment, net	209.9	213.7
Goodwill	0	0
Intercompany notes and accounts receivable	341.6	343.9
Other assets and deferred charges	666.7	662.6
Investment in subsidiaries	1,682.1	1,559
Total assets	4,875.6	3,508.2
Current liabilities
Current portion of long-term debt	0	0
Accounts payable	162.6	80.6
Intercompany payables	346.2	324.8
Accrued expenses and other	113.6	142.2
Total current liabilities	622.4	547.6
Intercompany notes and accounts payable	17.3	14.6
Long-term debt, net	2,520.1	1,339.7
Investment in Subsidiaries Obligation	0	0
Other long-term liabilities	752.9	754.5
Total liabilities	3,912.7	2,656.4
Total stockholders’ equity	962.9	851.8
Total liabilities and stockholders' equity	4,875.6	3,508.2
Guarantor Subsidiaries [Member]
Current assets
Cash and cash equivalents	0	1.6	0	0
Accounts receivable, net	23.9	21.9
Intercompany receivables	350.5	326
Inventories, net	31.6	29.1
Prepaid expenses and other	0.3	0.5
Total current assets	406.3	379.1
Property, plant and equipment, net	104.8	102.9
Goodwill	147.8	147.8
Intercompany notes and accounts receivable	243.9	242.2
Other assets and deferred charges	38.4	37.1
Investment in subsidiaries	0	0
Total assets	941.2	909.1
Current liabilities
Current portion of long-term debt	0	0
Accounts payable	43.6	35.8
Intercompany payables	159.8	153.4
Accrued expenses and other	4.5	4.3
Total current liabilities	207.9	193.5
Intercompany notes and accounts payable	2	7.5
Long-term debt, net	4	4.1
Investment in Subsidiaries Obligation	109.9	124.7
Other long-term liabilities	0.7	0.6
Total liabilities	324.5	330.4
Total stockholders’ equity	616.7	578.7
Total liabilities and stockholders' equity	941.2	909.1
Non-Guarantor Subsidiaries [Member]
Current assets
Cash and cash equivalents	130.1	395.3	154.8	230.5
Accounts receivable, net	503.3	411.4
Intercompany receivables	9	9.1
Inventories, net	146	144.4
Prepaid expenses and other	75	45.9
Total current assets	863.4	1,006.1
Property, plant and equipment, net	828.3	777.1
Goodwill	86	6.2
Intercompany notes and accounts receivable	0	0
Other assets and deferred charges	206.6	164.2
Investment in subsidiaries	0	0
Total assets	1,984.3	1,953.6
Current liabilities
Current portion of long-term debt	3.4	3.3
Accounts payable	321.7	265.9
Intercompany payables	165.5	299.5
Accrued expenses and other	123.3	119.4
Total current liabilities	613.9	688.1
Intercompany notes and accounts payable	239.1	242.2
Long-term debt, net	57.4	57.1
Investment in Subsidiaries Obligation	0	0
Other long-term liabilities	118.4	110.6
Total liabilities	1,028.8	1,098
Total stockholders’ equity	955.5	855.6
Total liabilities and stockholders' equity	1,984.3	1,953.6
Consolidation, Eliminations [Member]
Current assets
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	0	0
Intercompany receivables	(671.5)	(777.7)
Inventories, net	0	0
Prepaid expenses and other	0	0
Total current assets	(671.5)	(777.7)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intercompany notes and accounts receivable	(585.5)	(586.1)
Other assets and deferred charges	0	0
Investment in subsidiaries	(2,645)	(2,410.8)
Total assets	(3,902)	(3,774.6)
Current liabilities
Current portion of long-term debt	0	0
Accounts payable	0	0
Intercompany payables	(671.5)	(777.7)
Accrued expenses and other	0	0
Total current liabilities	(671.5)	(777.7)
Intercompany notes and accounts payable	(585.5)	(586.1)
Long-term debt, net	0	0
Investment in Subsidiaries Obligation	(109.9)	(124.7)
Other long-term liabilities	0	0
Total liabilities	(1,366.9)	(1,488.5)
Total stockholders’ equity	(2,535.1)	(2,286.1)
Total liabilities and stockholders' equity	$ (3,902)	$ (3,774.6)

Supplemental Guarantor Conden63

Supplemental Guarantor Condensed Consolidating Financial Statements Supplemental Guarantor Condensed Consolidating Statements of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net cash provided by operating activities	$ 62.3	$ 26.2
Investing activities
Purchases of property, plant and equipment	(34.9)	(50.6)
Proceeds from sale of property, plant and equipment	0.8	0.6
Purchase buyouts of leased equipment	(2.3)	0
Proceeds from sale of business, net	5.9	0
Acquisition of business, net	(144.1)	0
Net cash used in investing activities	(174.6)	(50)
Financing activities
Net debt activity	1,199.2	4.6
Debt issuance costs	(21.2)	0
Purchase of treasury stock	(5.2)	(3.5)
Intercompany Activity - Financing	0	0
Net cash provided by financing activities	1,172.8	1.1
Effect of exchange rate changes on cash	1.7	2.2
Net increase (decrease) in cash and cash equivalents	1,062.2	(20.5)
Cash and cash equivalents at beginning of period	481.2	282.5
Cash and cash equivalents at end of period	1,543.4	262
Holdings [Member]
Net cash provided by operating activities	0	0
Investing activities
Purchases of property, plant and equipment	0	0
Proceeds from sale of property, plant and equipment	0	0
Purchase buyouts of leased equipment	0
Proceeds from sale of business, net	0
Acquisition of business, net	0
Net cash used in investing activities	0	0
Financing activities
Net debt activity	0	0
Debt issuance costs	0
Purchase of treasury stock	(5.2)	(3.5)
Intercompany Activity - Financing	5.2	3.5
Net cash provided by financing activities	0	0
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
AAM Inc. [Member]
Net cash provided by operating activities	161.8	66.8
Investing activities
Purchases of property, plant and equipment	(11.6)	(7.9)
Proceeds from sale of property, plant and equipment	0.2	0
Purchase buyouts of leased equipment	(2.3)
Proceeds from sale of business, net	7.5
Acquisition of business, net	0
Net cash used in investing activities	(6.2)	(7.9)
Financing activities
Net debt activity	1,199.8	(0.2)
Debt issuance costs	(21.2)
Purchase of treasury stock	0	0
Intercompany Activity - Financing	(5.2)	(3.5)
Net cash provided by financing activities	1,173.4	(3.7)
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	1,329	55.2
Cash and cash equivalents at beginning of period	84.3	52
Cash and cash equivalents at end of period	1,413.3	107.2
Guarantor Subsidiaries [Member]
Net cash provided by operating activities	5.3	5.1
Investing activities
Purchases of property, plant and equipment	(5.2)	(5.2)
Proceeds from sale of property, plant and equipment	0	0.2
Purchase buyouts of leased equipment	0
Proceeds from sale of business, net	(1.6)
Acquisition of business, net	0
Net cash used in investing activities	(6.8)	(5)
Financing activities
Net debt activity	(0.1)	(0.1)
Debt issuance costs	0
Purchase of treasury stock	0	0
Intercompany Activity - Financing	0	0
Net cash provided by financing activities	(0.1)	(0.1)
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	(1.6)	0
Cash and cash equivalents at beginning of period	1.6	0
Cash and cash equivalents at end of period	0	0
Non-Guarantor Subsidiaries [Member]
Net cash provided by operating activities	(104.8)	(45.7)
Investing activities
Purchases of property, plant and equipment	(18.1)	(37.5)
Proceeds from sale of property, plant and equipment	0.6	0.4
Purchase buyouts of leased equipment	0
Proceeds from sale of business, net	0
Acquisition of business, net	(144.1)
Net cash used in investing activities	(161.6)	(37.1)
Financing activities
Net debt activity	(0.5)	4.9
Debt issuance costs	0
Purchase of treasury stock	0	0
Intercompany Activity - Financing	0	0
Net cash provided by financing activities	(0.5)	4.9
Effect of exchange rate changes on cash	1.7	2.2
Net increase (decrease) in cash and cash equivalents	(265.2)	(75.7)
Cash and cash equivalents at beginning of period	395.3	230.5
Cash and cash equivalents at end of period	130.1	154.8
Consolidation, Eliminations [Member]
Net cash provided by operating activities	0	0
Investing activities
Purchases of property, plant and equipment	0	0
Proceeds from sale of property, plant and equipment	0	0
Purchase buyouts of leased equipment	0
Proceeds from sale of business, net	0
Acquisition of business, net	0
Net cash used in investing activities	0	0
Financing activities
Net debt activity	0	0
Debt issuance costs	0
Purchase of treasury stock	0	0
Intercompany Activity - Financing	0	0
Net cash provided by financing activities	0	0
Effect of exchange rate changes on cash	0	0
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0