Description of the Business	6 Months Ended
Jun. 30, 2011
Description of the Business/Summary of Accounting Policies [Abstract]
Description of the Business	Note 1 — Description of the Business The condensed consolidated financial statements included herein have been prepared by American Railcar Industries, Inc. (a North Dakota corporation) and subsidiaries (collectively the Company or ARI), without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosure normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. The condensed consolidated balance sheet as of December 31, 2010 has been derived from the audited consolidated balance sheets as of that date. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s latest annual report on Form 10-K for the year ended December 31, 2010. In the opinion of management, the information contained herein reflects all adjustments necessary to make the results of operations for the interim periods fairly stated. The results of operations of any interim period are not necessarily indicative of the results that may be expected for a fiscal year. ARI manufactures railcars, which are offered for sale or lease, custom designed railcar parts and other industrial products, primarily aluminum and special alloy steel castings. These products are sold to various types of companies including leasing companies, railroads, industrial companies and other non-rail companies. ARI provides railcar repair and maintenance services for railcar fleets. In addition, ARI provides fleet management and maintenance services for railcars owned by certain customers. Such services include inspecting and supervising the maintenance and repair of such railcars. The condensed consolidated financial statements of the Company include the accounts of ARI and its direct and indirect wholly-owned subsidiaries; Castings, LLC (Castings), ARI Component Venture, LLC (ARI Component), American Railcar Mauritius I (ARM I), American Railcar Mauritius II (ARM II) and ARI Longtrain, Inc. (Longtrain). From time to time, the Company makes investments through Longtrain. For further information on the Company’s other wholly-owned subsidiaries, refer to Note 8. All intercompany transactions and balances have been eliminated. The Company’s operations are located in the United States and Canada. The Company operates a railcar repair facility in Sarnia, Ontario Canada. Canadian revenues were 1.4% and 2.4% of total consolidated revenues for the three months ended June 30, 2011 and 2010, respectively. Canadian revenues were 1.6% and 2.4% of total consolidated revenues for the six months ended June 30, 2011 and 2010, respectively. Canadian assets were 1.9% and 1.7% of total consolidated assets as of June 30, 2011 and December 31, 2010, respectively. In addition, the Company’s subsidiaries ARM I and ARM II are located in Mauritius, through which the Company holds a 50% interest in an Indian joint venture. Refer to Note 8 for further information. Assets held by ARM I and ARM II were 1.4% and 1.5% of total consolidated assets as of June 30, 2011 and December 31, 2010, respectively.

Note 1 — Description of the Business

The condensed consolidated financial statements included herein have been prepared by American Railcar Industries, Inc. (a North Dakota corporation) and subsidiaries (collectively the Company or ARI), without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosure normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations, although the Company believes that the disclosures are adequate to make the information presented not misleading. The condensed consolidated balance sheet as of December 31, 2010 has been derived from the audited consolidated balance sheets as of that date. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s latest annual report on Form 10-K for the year ended December 31, 2010. In the opinion of management, the information contained herein reflects all adjustments necessary to make the results of operations for the interim periods fairly stated. The results of operations of any interim period are not necessarily indicative of the results that may be expected for a fiscal year.

ARI manufactures railcars, which are offered for sale or lease, custom designed railcar parts and other industrial products, primarily aluminum and special alloy steel castings. These products are sold to various types of companies including leasing companies, railroads, industrial companies and other non-rail companies. ARI provides railcar repair and maintenance services for railcar fleets. In addition, ARI provides fleet management and maintenance services for railcars owned by certain customers. Such services include inspecting and supervising the maintenance and repair of such railcars.

The condensed consolidated financial statements of the Company include the accounts of ARI and its direct and indirect wholly-owned subsidiaries; Castings, LLC (Castings), ARI Component Venture, LLC (ARI Component), American Railcar Mauritius I (ARM I), American Railcar Mauritius II (ARM II) and ARI Longtrain, Inc. (Longtrain). From time to time, the Company makes investments through Longtrain. For further information on the Company’s other wholly-owned subsidiaries, refer to Note 8. All intercompany transactions and balances have been eliminated.

The Company’s operations are located in the United States and Canada. The Company operates a railcar repair facility in Sarnia, Ontario Canada. Canadian revenues were 1.4% and 2.4% of total consolidated revenues for the three months ended June 30, 2011 and 2010, respectively. Canadian revenues were 1.6% and 2.4% of total consolidated revenues for the six months ended June 30, 2011 and 2010, respectively. Canadian assets were 1.9% and 1.7% of total consolidated assets as of June 30, 2011 and December 31, 2010, respectively. In addition, the Company’s subsidiaries ARM I and ARM II are located in Mauritius, through which the Company holds a 50% interest in an Indian joint venture. Refer to Note 8 for further information. Assets held by ARM I and ARM II were 1.4% and 1.5% of total consolidated assets as of June 30, 2011 and December 31, 2010, respectively.