Significant Accounting Policies and Change in Accounting Principles	6 Months Ended
Sep. 30, 2011
Significant Accounting Policies and Change in Accounting Principles [Abstract]
Significant Accounting Policies and Change in Accounting Principles	Note 2: Significant Accounting Policies and Change in Accounting Principles Restricted cash: At September 30, 2011 and March 31, 2011, the Company had long-term restricted cash of $4,173 and $4,682, respectively, included in other noncurrent assets, consisting of $1,823 and $2,332, respectively, to secure long-term employee compensation arrangements for certain employees in Europe and $2,350 to collateralize insurance liabilities with an insurance carrier in North America. Joint venture: During the first quarter of fiscal 2012, the Company completed the formation of its joint venture with OneGene, Inc. to form Modine OneGene Corporation in South Korea. The Company and OneGene, Inc. made initial capital contributions of 1,000,000 Korean won ($936 U.S. equivalent) each during the first quarter of fiscal 2012. Modine is considered the primary beneficiary of the joint venture in accordance with applicable consolidation guidance. Accordingly, the results of Modine OneGene Corporation are consolidated by the Company. Revision of prior period financial statements: As described in Note 1 and Note 26 of the Notes to Consolidated Financial Statements in Modine's Annual Report on Form 10-K for the year ended March 31, 2011, the quarterly results for fiscal 2011 have been revised as a result of errors identified during fiscal 2011 which were not considered material individually or in the aggregate to previously issued financial statements but were considered significant to the quarters in which they were identified. For the three months ended September 30, 2010, cost of goods sold increased $1,858, selling, general and administrative expenses increased $260, provision for income taxes decreased $190 and earnings from continuing operations decreased $1,928 as a result of the revisions. For the six months ended September 30, 2010, net sales increased $363, cost of goods sold increased $1,919, gross profit decreased $1,556, selling, general and administrative expenses increased $611, provision for income taxes increased $139 and earnings from continuing operations decreased $2,306 as a result of the revisions. For the three and six months ended September 30, 2010, diluted earnings per share from continuing operations and diluted net earnings per share decreased $0.04 and $0.05, respectively, as a result of these revisions. Out of period adjustments: During the three months ended September 30, 2011, the Company identified two items that should have been recorded in the first quarter of fiscal 2012, but were instead corrected in the second quarter of fiscal 2012. Such errors overstated fiscal 2012 first quarter net income by approximately $438, and related to (1) an understatement of foreign currency transactions gains of $197, included in other expense (income) – net; and (2) an understatement of income tax expense of $635. The adjustments were not considered material to the financial statements of either the first quarter or second quarter of fiscal 2012. Accounting standards changes and new accounting pronouncements: In October 2009, the Financial Accounting Standards Board (FASB) issued updated guidance on revenue arrangements with multiple deliverables, which addresses the unit of accounting for multiple-deliverable arrangements and revises the method by which consideration is allocated among the units of accounting. The overall consideration is allocated to each deliverable by establishing a selling price for individual deliverables based on a hierarchy of evidence, including vendor-specific objective evidence, other third party evidence of the selling price, or the reporting entity's best estimate of the selling price of individual deliverables in the arrangement. This guidance was effective for the Company on a prospective basis on April 1, 2011. The adoption of this guidance did not have a material impact on the consolidated financial statements. In June 2011, the FASB issued an amendment to the accounting guidance for the presentation of comprehensive income. This amendment removes one of the three presentation options for presenting the components of other comprehensive income as part of the statement of changes in shareholders' equity and requires either a single continuous statement of net income and other comprehensive income or a two consecutive statement approach. This amendment shall be applied retrospectively and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2011. The Company is currently evaluating the impact of this amendment. In September 2011, the FASB issued an amendment to the accounting guidance for testing goodwill for impairment. The amendment provides an option for companies to first use a qualitative approach to test goodwill for impairment if certain conditions are met. If it is determined to be more likely than not that the fair value of the reporting unit is less than its carrying amount, entities must perform the quantitative analysis of the goodwill impairment test. The amendments are effective for goodwill impairment tests performed for fiscal years beginning after December 15, 2011. The Company is assessing this new guidance and currently does not anticipate a material impact on the consolidated financial statements.

Note 2: Significant Accounting Policies and Change in Accounting Principles

Restricted cash: At September 30, 2011 and March 31, 2011, the Company had long-term restricted cash of $4,173 and $4,682, respectively, included in other noncurrent assets, consisting of $1,823 and $2,332, respectively, to secure long-term employee compensation arrangements for certain employees in Europe and $2,350 to collateralize insurance liabilities with an insurance carrier in North America.

Joint venture: During the first quarter of fiscal 2012, the Company completed the formation of its joint venture with OneGene, Inc. to form Modine OneGene Corporation in South Korea. The Company and OneGene, Inc. made initial capital contributions of 1,000,000 Korean won ($936 U.S. equivalent) each during the first quarter of fiscal 2012. Modine is considered the primary beneficiary of the joint venture in accordance with applicable consolidation guidance. Accordingly, the results of Modine OneGene Corporation are consolidated by the Company.

Revision of prior period financial statements: As described in Note 1 and Note 26 of the Notes to Consolidated Financial Statements in Modine's Annual Report on Form 10-K for the year ended March 31, 2011, the quarterly results for fiscal 2011 have been revised as a result of errors identified during fiscal 2011 which were not considered material individually or in the aggregate to previously issued financial statements but were considered significant to the quarters in which they were identified. For the three months ended September 30, 2010, cost of goods sold increased $1,858, selling, general and administrative expenses increased $260, provision for income taxes decreased $190 and earnings from continuing operations decreased $1,928 as a result of the revisions. For the six months ended September 30, 2010, net sales increased $363, cost of goods sold increased $1,919, gross profit decreased $1,556, selling, general and administrative expenses increased $611, provision for income taxes increased $139 and earnings from continuing operations decreased $2,306 as a result of the revisions. For the three and six months ended September 30, 2010, diluted earnings per share from continuing operations and diluted net earnings per share decreased $0.04 and $0.05, respectively, as a result of these revisions.

Out of period adjustments: During the three months ended September 30, 2011, the Company identified two items that should have been recorded in the first quarter of fiscal 2012, but were instead corrected in the second quarter of fiscal 2012. Such errors overstated fiscal 2012 first quarter net income by approximately $438, and related to (1) an understatement of foreign currency transactions gains of $197, included in other expense (income) – net; and (2) an understatement of income tax expense of $635. The adjustments were not considered material to the financial statements of either the first quarter or second quarter of fiscal 2012.

Accounting standards changes and new accounting pronouncements: In October 2009, the Financial Accounting Standards Board (FASB) issued updated guidance on revenue arrangements with multiple deliverables, which addresses the unit of accounting for multiple-deliverable arrangements and revises the method by which consideration is allocated among the units of accounting. The overall consideration is allocated to each deliverable by establishing a selling price for individual deliverables based on a hierarchy of evidence, including vendor-specific objective evidence, other third party evidence of the selling price, or the reporting entity's best estimate of the selling price of individual deliverables in the arrangement. This guidance was effective for the Company on a prospective basis on April 1, 2011. The adoption of this guidance did not have a material impact on the consolidated financial statements.

In June 2011, the FASB issued an amendment to the accounting guidance for the presentation of comprehensive income. This amendment removes one of the three presentation options for presenting the components of other comprehensive income as part of the statement of changes in shareholders' equity and requires either a single continuous statement of net income and other comprehensive income or a two consecutive statement approach. This amendment shall be applied retrospectively and is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2011. The Company is currently evaluating the impact of this amendment.

In September 2011, the FASB issued an amendment to the accounting guidance for testing goodwill for impairment. The amendment provides an option for companies to first use a qualitative approach to test goodwill for impairment if certain conditions are met. If it is determined to be more likely than not that the fair value of the reporting unit is less than its carrying amount, entities must perform the quantitative analysis of the goodwill impairment test. The amendments are effective for goodwill impairment tests performed for fiscal years beginning after December 15, 2011. The Company is assessing this new guidance and currently does not anticipate a material impact on the consolidated financial statements.