Description of Business	12 Months Ended
Dec. 31, 2012
Description of Business [Abstract]
Description of Business	Describtion of Business Description of Business Ampco-Pittsburgh Corporation (the “Corporation”) operates in two business segments. The Forged and Cast Rolls segment consists of Union Electric Steel Corporation (“Union Electric Steel” or “UES”) and Union Electric Steel UK Limited (“UES-UK”). Union Electric Steel is one of the world’s largest manufacturers of forged hardened steel rolls with principal operations in Pennsylvania and Indiana whereas UES-UK produces cast iron and steel rolls in England. Rolls are supplied to manufacturers of steel and aluminum throughout the world. The Air and Liquid Processing segment includes Aerofin, Buffalo Air Handling and Buffalo Pumps, all divisions of Air & Liquid Systems Corporation, a wholly-owned subsidiary of the Corporation. Aerofin produces custom-engineered finned tube heat exchange coils and related heat transfer products for a variety of industries including fossil fuel and nuclear power generation, automotive, industrial process and HVAC. Buffalo Air Handling makes custom-designed air handling systems for commercial, institutional and industrial building markets. Buffalo Pumps manufactures centrifugal pumps for the defense, refrigeration and power generation industries. The segment has operations in Virginia and New York with headquarters in Pennsylvania. The segment distributes a significant portion of its products through a common independent group of sales offices located throughout the U.S. and Canada.

Description of Business

12 Months Ended

Dec. 31, 2012

Description of Business

Ampco-Pittsburgh Corporation (the “Corporation”) operates in two business segments. The Forged and Cast Rolls segment consists of Union Electric Steel Corporation (“Union Electric Steel” or “UES”) and Union Electric Steel UK Limited (“UES-UK”). Union Electric Steel is one of the world’s largest manufacturers of forged hardened steel rolls with principal operations in Pennsylvania and Indiana whereas UES-UK produces cast iron and steel rolls in England. Rolls are supplied to manufacturers of steel and aluminum throughout the world. The Air and Liquid Processing segment includes Aerofin, Buffalo Air Handling and Buffalo Pumps, all divisions of Air & Liquid Systems Corporation, a wholly-owned subsidiary of the Corporation. Aerofin produces custom-engineered finned tube heat exchange coils and related heat transfer products for a variety of industries including fossil fuel and nuclear power generation, automotive, industrial process and HVAC. Buffalo Air Handling makes custom-designed air handling systems for commercial, institutional and industrial building markets. Buffalo Pumps manufactures centrifugal pumps for the defense, refrigeration and power generation industries. The segment has operations in Virginia and New York with headquarters in Pennsylvania. The segment distributes a significant portion of its products through a common independent group of sales offices located throughout the U.S. and Canada.