Contingencies	9 Months Ended
Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Structural Systems has been directed by California environmental agencies to investigate and take corrective action for groundwater contamination at its facilities located in El Mirage and Monrovia, California. Based on currently available information, Ducommun has established an accrual for its estimated liability for such investigation and corrective action of $1.5 million at both September 30, 2017 and December 31, 2016, which is reflected in other long-term liabilities on its condensed consolidated balance sheets. Structural Systems also faces liability as a potentially responsible party for hazardous waste disposed at landfills located in Casmalia and West Covina, California. Structural Systems and other companies and government entities have entered into consent decrees with respect to these landfills with the United States Environmental Protection Agency and/or California environmental agencies under which certain investigation, remediation and maintenance activities are being performed. Based on currently available information, Ducommun preliminarily estimates that the range of its future liabilities in connection with the landfill located in West Covina, California is between $0.4 million and $3.1 million. Ducommun has established an accrual for its estimated liability, in connection with the West Covina landfill of $0.4 million at September 30, 2017, which is reflected in other long-term liabilities on its condensed consolidated balance sheet. Ducommun’s ultimate liability in connection with these matters will depend upon a number of factors, including changes in existing laws and regulations, the design and cost of construction, operation and maintenance activities, and the allocation of liability among potentially responsible parties. In the normal course of business, Ducommun and its subsidiaries are defendants in certain other litigation, claims and inquiries, including matters relating to environmental laws. In addition, Ducommun makes various commitments and incurs contingent liabilities. While it is not feasible to predict the outcome of these matters, Ducommun does not presently expect that any sum it may be required to pay in connection with these matters would have a material adverse effect on its condensed consolidated financial position, results of operations or cash flows.

Contingencies

Structural Systems has been directed by California environmental agencies to investigate and take corrective action for groundwater contamination at its facilities located in El Mirage and Monrovia, California. Based on currently available information, Ducommun has established an accrual for its estimated liability for such investigation and corrective action of $1.5 million at both September 30, 2017 and December 31, 2016, which is reflected in other long-term liabilities on its condensed consolidated balance sheets.

Structural Systems also faces liability as a potentially responsible party for hazardous waste disposed at landfills located in Casmalia and West Covina, California. Structural Systems and other companies and government entities have entered into consent decrees with respect to these landfills with the United States Environmental Protection Agency and/or California environmental agencies under which certain investigation, remediation and maintenance activities are being performed. Based on currently available information, Ducommun preliminarily estimates that the range of its future liabilities in connection with the landfill located in West Covina, California is between $0.4 million and $3.1 million. Ducommun has established an accrual for its estimated liability, in connection with the West Covina landfill of $0.4 million at September 30, 2017, which is reflected in other long-term liabilities on its condensed consolidated balance sheet. Ducommun’s ultimate liability in connection with these matters will depend upon a number of factors, including changes in existing laws and regulations, the design and cost of construction, operation and maintenance activities, and the allocation of liability among potentially responsible parties.

In the normal course of business, Ducommun and its subsidiaries are defendants in certain other litigation, claims and inquiries, including matters relating to environmental laws. In addition, Ducommun makes various commitments and incurs contingent liabilities. While it is not feasible to predict the outcome of these matters, Ducommun does not presently expect that any sum it may be required to pay in connection with these matters would have a material adverse effect on its condensed consolidated financial position, results of operations or cash flows.