Basis of Presentation (Policies)

9 Months Ended

Sep. 30, 2013

Accounting Policies [Abstract]

Consolidation Policy

The Condensed Consolidated Financial Statements include the accounts of Northwest Pipe Company (the “Company”) and its subsidiaries in which the Company exercises control as of the financial statement date. Intercompany accounts and transactions have been eliminated.

Basis of Accounting

The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America. The financial information as of December 31, 2012 is derived from the audited consolidated financial statements presented in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 (the “2012 Form 10-K”). Certain information or footnote disclosures normally included in consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been condensed or omitted, pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). In the opinion of management, the accompanying Condensed Consolidated Financial Statements include all adjustments necessary (which are of a normal and recurring nature) for the fair statement of the results of the interim periods presented. The Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and notes thereto together with management’s discussion and analysis of financial condition and results of operations contained in the Company’s 2012 Form 10-K.