Basis of Presentation and Consolidation	12 Months Ended
Dec. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation and Consolidation	(2) Basis of Presentation and Consolidation Basis of Presentation Metaldyne Performance Group Inc. was formed through the reorganization of ASP HHI Holdings, Inc. (together with its subsidiaries, “HHI”), ASP MD Holdings, Inc. (together with its subsidiaries, “Metaldyne”) and ASP Grede Intermediate Holdings LLC (together with its subsidiaries, “Grede”) on August 4, 2014 (the “Combination”). The Combination occurred through mergers with three separate wholly owned merger subsidiaries of Metaldyne Performance Group Inc. (“MPG,” the “Company,” “we,” “our” and “us” and similar terms refer to Metaldyne Performance Group Inc. and all of its subsidiaries, including HHI, Metaldyne and Grede). In connection with the Combination, 13.4 million shares of MPG common stock were issued in exchange for the outstanding shares of HHI, Metaldyne and Grede. On November 18, 2014, the outstanding shares of MPG common stock were split at a 5-to-1 ratio (the “Stock Split”). After the Stock Split, 67.1 million shares were outstanding. The number of authorized shares was increased to 400.0 million. Consolidation The Combination has been accounted for as a reorganization of entities under common control in a manner similar to a pooling of interests, that is, the bases of accounting of HHI, Metaldyne and Grede were carried over to MPG. These financial statements reflect the retrospective application of the MPG capital structure and the Stock Split for all periods presented. All intercompany balances and transactions have been eliminated in consolidation.

(2) Basis of Presentation and Consolidation

Basis of Presentation

Metaldyne Performance Group Inc. was formed through the reorganization of ASP HHI Holdings, Inc. (together with its subsidiaries, “HHI”), ASP MD Holdings, Inc. (together with its subsidiaries, “Metaldyne”) and ASP Grede Intermediate Holdings LLC (together with its subsidiaries, “Grede”) on August 4, 2014 (the “Combination”). The Combination occurred through mergers with three separate wholly owned merger subsidiaries of Metaldyne Performance Group Inc. (“MPG,” the “Company,” “we,” “our” and “us” and similar terms refer to Metaldyne Performance Group Inc. and all of its subsidiaries, including HHI, Metaldyne and Grede). In connection with the Combination, 13.4 million shares of MPG common stock were issued in exchange for the outstanding shares of HHI, Metaldyne and Grede. On November 18, 2014, the outstanding shares of MPG common stock were split at a 5-to-1 ratio (the “Stock Split”). After the Stock Split, 67.1 million shares were outstanding. The number of authorized shares was increased to 400.0 million.

Consolidation

The Combination has been accounted for as a reorganization of entities under common control in a manner similar to a pooling of interests, that is, the bases of accounting of HHI, Metaldyne and Grede were carried over to MPG. These financial statements reflect the retrospective application of the MPG capital structure and the Stock Split for all periods presented.

All intercompany balances and transactions have been eliminated in consolidation.