Nature of Operations and Summary of Significant Accounting Policies	9 Months Ended
Dec. 31, 2011
Notes To Financial Statements [Abstract]
Nature of Operations and Summary of Significant Accounting Policies	Nature of Operations and Summary of Significant Accounting Policies Nature of Operations STERIS Corporation, an Ohio corporation, develops, manufactures and markets infection prevention, contamination control, microbial reduction, and surgical and critical care support products and services for healthcare, pharmaceutical, scientific, research, industrial, and governmental Customers throughout the world. As used in this Quarterly Report, STERIS Corporation and its subsidiaries together are called “STERIS,” the “Company,” “we,” “us,” or “our,” unless otherwise noted. We operate in three reportable business segments: Healthcare, Life Sciences, and STERIS Isomedix Services (“Isomedix”). We describe our business segments in note 11 to our consolidated financial statements titled, “Business Segment Information.” Our fiscal year ends on March 31. References in this Quarterly Report to a particular “year” or “year-end” mean our fiscal year. The significant accounting policies applied in preparing the accompanying consolidated financial statements of the Company are summarized below: Interim Financial Statements We prepared the accompanying unaudited consolidated financial statements of the Company according to accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and the instructions to the Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. This means that they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Our unaudited interim consolidated financial statements contain all material adjustments (consisting of normal recurring accruals and adjustments) management believes are necessary to fairly state our financial condition, results of operations, and cash flows for the periods presented. These interim consolidated financial statements should be read together with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended March 31, 2011, filed with the Securities and Exchange Commission (“SEC”) on May 27, 2011. The Consolidated Balance Sheet at March 31, 2011 was derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Principles of Consolidation We use the consolidation method to report our investment in our subsidiaries. Therefore, the accompanying consolidated financial statements include the accounts of the Company and its wholly-owned and majority-owned subsidiaries. We eliminate inter-company accounts and transactions when we consolidate these accounts. Use of Estimates We make certain estimates and assumptions when preparing financial statements according to U.S. GAAP that affect the reported amounts of assets and liabilities at the financial statement dates and the reported amounts of revenues and expenses during the periods presented. These estimates and assumptions involve judgments with respect to many factors that are difficult to predict and are beyond our control. Actual results could be materially different from these estimates. We revise the estimates and assumptions as new information becomes available. This means that operating results for the three and nine month periods ended December 31, 2011 are not necessarily indicative of results that may be expected for future quarters or for the full fiscal year ending March 31, 2012. Recently Adopted Accounting Pronouncements In September 2011, the FASB issued an accounting standard update titled “Testing Goodwill for Impairment,” which allows an entity the option of performing a qualitative assessment to determine whether it is necessary to perform the current two-step annual impairment test. The guidance permits an entity to assess qualitative factors to determine if it is more-likely-than-not that the fair value of the reporting unit exceeds the carrying amount to determine if the two-step impairment test is required. The guidance does not change how goodwill is calculated or the requirement to test goodwill annually for impairment. The new guidance is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011, with early adoption permitted. The early adoption of this standard did not have an impact on our consolidated financial position, results of operations or cash flows. In June 2011, the FASB issued new guidance titled "Comprehensive Income," which altered the presentation of comprehensive income. More specifically, the updated guidance permits an entity to present components of net income and other comprehensive income in either one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive statements. The guidance now eliminates the current option to report other comprehensive income and its components in the statement of changes in equity. These changes to the presentation of comprehensive income do not change the components that are recognized in net income or other comprehensive income under current accounting guidance. This guidance is effective for fiscal years and interim periods beginning after December 15, 2011 and will become effective for us at the beginning of our first quarter of fiscal 2013. The adoption of this standard will not have an impact on our consolidated financial position, results of operations or cash flows. In April 2011, the FASB issued new guidance titled "Fair Value Measurement," intended to achieve common fair value measurement and disclosure requirements between GAAP and International Financial Reporting Standards. This new guidance amends current fair value measurement and disclosure guidance to include increased transparency regarding valuation inputs and investment categorization. This new guidance is effective for annual and interim periods beginning after December 15, 2011 and will become effective for us at the beginning of our first quarter of fiscal 2013. The adoption of this standard will not have an impact on our consolidated financial position, results of operations or cash flows. In December 2010, the FASB issued an accounting standard update titled “When to Perform Step 2 of the Goodwill Impairment Test for Reporting Units with Zero or Negative Carrying Amounts," amending Accounting Standards Codification (ASC) Topic 350, “Intangibles - Goodwill and Other.” This guidance amends the ASC requiring entities that have a reporting unit with zero or negative carrying value to assess whether qualitative factors indicate that it is more likely than not that an impairment of goodwill exists. If the entity concludes that it is more likely than not that an impairment exists, the entity must then measure the goodwill impairment. The new guidance, amending the ASC is effective for fiscal 2012 and was applied during our annual goodwill impairment testing in the third quarter of fiscal 2012 and did not impact our results. In October 2009, the FASB issued an accounting standard update titled “Multiple-Deliverable Revenue Arrangements,” amending Accounting Standards Codification (ASC) Topic 605, “Revenue Recognition.” This guidance amends the ASC requiring entities to eliminate the residual method of allocation for multiple-deliverable revenue arrangements, requiring arrangement consideration be allocated at the inception of an arrangement to all deliverables using the relative selling price method. The guidance also established a selling price hierarchy for determining the selling price of a deliverable, which includes: (1) vendor-specific objective evidence if available, (2) third-party evidence if vendor-specific objective evidence is not available, and (3) estimated selling price if neither vendor-specific nor third-party evidence is available. The guidance was adopted and applied prospectively for multiple element revenue arrangements that are new or materially modified beginning on or after April 1, 2011. The adoption of this guidance did not impact our financial position or results of operations. Significant Accounting Policies A detailed description of our significant and critical accounting policies, estimates, and assumptions is included in our consolidated financial statements included in our Annual Report on Form 10-K for the year ended March 31, 2011, filed with the SEC on May 27, 2011. Our significant and critical accounting policies, estimates, and assumptions have not changed materially from March 31, 2011. The Accrued SYSTEM 1 Rebate Program (the “Rebate Program”), initially recognized during the first quarter of fiscal 2011, is based upon the quantity of SYSTEM 1 processors eligible for rebates and the estimated value of rebates to be provided upon their return. Rebates of $102,313 were recognized as contra-revenue consistent with other returns and allowances offered to Customers. The estimated cost of $7,691 to facilitate the disposal of the returned SYSTEM 1 processors has been recognized as cost of revenues. Both components are recorded as current liabilities. The key assumptions involved in the estimates associated with the Rebate Program include: the number and age of SYSTEM 1 processors eligible for rebates under the Rebate Program, the number of Customers that will elect to participate in the Rebate Program, the proportion of Customers that will choose each rebate option, and the estimated per unit costs of disposal. The number and age of SYSTEM 1 processors has been estimated based on our historical sales and service records and we have assumed that 100% of eligible Customers will elect to participate in the Rebate Program. In order to estimate the portion of Customers that will choose each available rebate option, we first assessed trends in sales of the proprietary consumable products utilized in the SYSTEM 1 processor. We noted a decline of approximately 19% in shipments of SYSTEM 1 consumables during the period between the notice by FDA to healthcare facility administrators and infection control practitioners and the announcement of the Rebate Program, which indicated that a portion of our Customers had already transitioned away from the SYSTEM 1 technology during that period. The remaining 81% provided the best available indication of the portion of Customers projected to elect the rebate for the SYSTEM 1E processor. Order and quote data for fiscal 2011 provided indications of the proportion of Customers that are expected to choose each of the other rebate options. The per unit costs associated with disposal were estimated based on the service hours involved and quotes from our vendors using existing freight and disposal contracts.

Nature of Operations and Summary of Significant Accounting Policies

Nature of Operations

STERIS Corporation, an Ohio corporation, develops, manufactures and markets infection prevention, contamination control, microbial reduction, and surgical and critical care support products and services for healthcare, pharmaceutical, scientific, research, industrial, and governmental Customers throughout the world. As used in this Quarterly Report, STERIS Corporation and its subsidiaries together are called “STERIS,” the “Company,” “we,” “us,” or “our,” unless otherwise noted.

We operate in three reportable business segments: Healthcare, Life Sciences, and STERIS Isomedix Services (“Isomedix”). We describe our business segments in note 11 to our consolidated financial statements titled, “Business Segment Information.” Our fiscal year ends on March 31. References in this Quarterly Report to a particular “year” or “year-end” mean our fiscal year. The significant accounting policies applied in preparing the accompanying consolidated financial statements of the Company are summarized below:

Interim Financial Statements

We prepared the accompanying unaudited consolidated financial statements of the Company according to accounting principles generally accepted in the United States (“U.S. GAAP”) for interim financial information and the instructions to the Quarterly Report on Form 10-Q and Rule 10-01 of Regulation S-X. This means that they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Our unaudited interim consolidated financial statements contain all material adjustments (consisting of normal recurring accruals and adjustments) management believes are necessary to fairly state our financial condition, results of operations, and cash flows for the periods presented.

These interim consolidated financial statements should be read together with the consolidated financial statements and related notes included in our Annual Report on Form 10-K for the year ended March 31, 2011, filed with the Securities and Exchange Commission (“SEC”) on May 27, 2011. The Consolidated Balance Sheet at March 31, 2011 was derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements.

Principles of Consolidation

We use the consolidation method to report our investment in our subsidiaries. Therefore, the accompanying consolidated financial statements include the accounts of the Company and its wholly-owned and majority-owned subsidiaries. We eliminate inter-company accounts and transactions when we consolidate these accounts.

Use of Estimates

We make certain estimates and assumptions when preparing financial statements according to U.S. GAAP that affect the reported amounts of assets and liabilities at the financial statement dates and the reported amounts of revenues and expenses during the periods presented. These estimates and assumptions involve judgments with respect to many factors that are difficult to predict and are beyond our control. Actual results could be materially different from these estimates. We revise the estimates and assumptions as new information becomes available. This means that operating results for the three and nine month periods ended December 31, 2011 are not necessarily indicative of results that may be expected for future quarters or for the full fiscal year ending March 31, 2012.

Recently Adopted Accounting Pronouncements

In September 2011, the FASB issued an accounting standard update titled “Testing Goodwill for Impairment,” which allows an entity the option of performing a qualitative assessment to determine whether it is necessary to perform the current two-step annual impairment test. The guidance permits an entity to assess qualitative factors to determine if it is more-likely-than-not that the fair value of the reporting unit exceeds the carrying amount to determine if the two-step impairment test is required. The guidance does not change how goodwill is calculated or the requirement to test goodwill annually for impairment. The new guidance is effective for annual and interim goodwill impairment tests performed for fiscal years beginning after December 15, 2011, with early adoption permitted. The early adoption of this standard did not have an impact on our consolidated financial position, results of operations or cash flows.

In June 2011, the FASB issued new guidance titled "Comprehensive Income," which altered the presentation of comprehensive income. More specifically, the updated guidance permits an entity to present components of net income and other comprehensive income in either one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive statements. The guidance now eliminates the current option to report other comprehensive income and its components in the statement of changes in equity. These changes to the presentation of comprehensive income do not change the components that are recognized in net income or other comprehensive income under current accounting guidance. This guidance is effective for fiscal years and interim periods beginning after December 15, 2011 and will become effective for us at the beginning of our first quarter of fiscal 2013. The adoption of this standard will not have an impact on our consolidated financial position, results of operations or cash flows.

In April 2011, the FASB issued new guidance titled "Fair Value Measurement," intended to achieve common fair value measurement and disclosure requirements between GAAP and International Financial Reporting Standards. This new guidance amends current fair value measurement and disclosure guidance to include increased transparency regarding valuation inputs and investment categorization. This new guidance is effective for annual and interim periods beginning after December 15, 2011 and will become effective for us at the beginning of our first quarter of fiscal 2013. The adoption of this standard will not have an impact on our consolidated financial position, results of operations or cash flows.

In December 2010, the FASB issued an accounting standard update titled “When to Perform Step 2 of the Goodwill Impairment Test for Reporting Units with Zero or Negative Carrying Amounts," amending Accounting Standards Codification (ASC) Topic 350, “Intangibles - Goodwill and Other.” This guidance amends the ASC requiring entities that have a reporting unit with zero or negative carrying value to assess whether qualitative factors indicate that it is more likely than not that an impairment of goodwill exists. If the entity concludes that it is more likely than not that an impairment exists, the entity must then measure the goodwill impairment. The new guidance, amending the ASC is effective for fiscal 2012 and was applied during our annual goodwill impairment testing in the third quarter of fiscal 2012 and did not impact our results.

In October 2009, the FASB issued an accounting standard update titled “Multiple-Deliverable Revenue Arrangements,” amending Accounting Standards Codification (ASC) Topic 605, “Revenue Recognition.” This guidance amends the ASC requiring entities to eliminate the residual method of allocation for multiple-deliverable revenue arrangements, requiring arrangement consideration be allocated at the inception of an arrangement to all deliverables using the relative selling price method. The guidance also established a selling price hierarchy for determining the selling price of a deliverable, which includes: (1) vendor-specific objective evidence if available, (2) third-party evidence if vendor-specific objective evidence is not available, and (3) estimated selling price if neither vendor-specific nor third-party evidence is available. The guidance was adopted and applied prospectively for multiple element revenue arrangements that are new or materially modified beginning on or after April 1, 2011. The adoption of this guidance did not impact our financial position or results of operations.

Significant Accounting Policies

A detailed description of our significant and critical accounting policies, estimates, and assumptions is included in our consolidated financial statements included in our Annual Report on Form 10-K for the year ended March 31, 2011, filed with the SEC on May 27, 2011. Our significant and critical accounting policies, estimates, and assumptions have not changed materially from March 31, 2011.

The Accrued SYSTEM 1 Rebate Program (the “Rebate Program”), initially recognized during the first quarter of fiscal 2011, is based upon the quantity of SYSTEM 1 processors eligible for rebates and the estimated value of rebates to be provided upon their return. Rebates of $102,313 were recognized as contra-revenue consistent with other returns and allowances offered to Customers. The estimated cost of $7,691 to facilitate the disposal of the returned SYSTEM 1 processors has been recognized as cost of revenues. Both components are recorded as current liabilities. The key assumptions involved in the estimates associated with the Rebate Program include: the number and age of SYSTEM 1 processors eligible for rebates under the Rebate Program, the number of Customers that will elect to participate in the Rebate Program, the proportion of Customers that will choose each rebate option, and the estimated per unit costs of disposal.

The number and age of SYSTEM 1 processors has been estimated based on our historical sales and service records and we have assumed that 100% of eligible Customers will elect to participate in the Rebate Program. In order to estimate the portion of Customers that will choose each available rebate option, we first assessed trends in sales of the proprietary consumable products utilized in the SYSTEM 1 processor. We noted a decline of approximately 19% in shipments of SYSTEM 1 consumables during the period between the notice by FDA to healthcare facility administrators and infection control practitioners and the announcement of the Rebate Program, which indicated that a portion of our Customers had already transitioned away from the SYSTEM 1 technology during that period. The remaining 81% provided the best available indication of the portion of Customers projected to elect the rebate for the SYSTEM 1E processor. Order and quote data for fiscal 2011 provided indications of the proportion of Customers that are expected to choose each of the other rebate options. The per unit costs associated with disposal were estimated based on the service hours involved and quotes from our vendors using existing freight and disposal contracts.