Business acquisitions

3 Months Ended

Mar. 31, 2017

Business Combinations [Abstract]

Business acquisitions

Business acquisitions

Acquisition of Mt. Holly aluminum smelter

In 2014, our wholly-owned subsidiary, Berkeley Aluminum Inc. (“Berkeley”, which already owned 49.7% of the Mt. Holly smelter) entered into a stock purchase agreement (the "Stock Purchase Agreement") with Alumax Inc. ("Alumax"), a wholly-owned subsidiary of Alcoa Inc. ("Alcoa"), pursuant to which Berkeley acquired all of the issued and outstanding shares of Alumax of South Carolina, Inc. ("Alumax of SC") and thereby became the owner of 100% of the Mt. Holly smelter.  Pursuant to the terms of the Stock Purchase Agreement, Berkeley acquired all of the issued and outstanding shares of capital stock of Alumax of SC for $67,500 in cash subject to a contingent earn-out payment, working capital and other similar adjustments.  We received payments from Alcoa of $12,500 in settlement of the contingent consideration in March 2016, $11,313 for economic and working capital adjustments in April 2015 and $2,400 at closing which was primarily for post-employment benefits.  The total net cash consideration paid to Alcoa after final resolution of all post-closing adjustments, including the earn-out provision, was $41,487.  Immediately following the consummation of the transaction, Berkeley merged with and into Alumax of SC with Alumax of SC surviving and changing its name to Century Aluminum of South Carolina, Inc.