2.4.0.814090 - Disclosure - Retirement Savings Plan (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$D2012http://www.sec.gov/CIK0001035688duration2012-01-01T00:00:002012-12-31T00:00:00PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2011http://www.sec.gov/CIK0001035688duration2011-01-01T00:00:002011-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$D2010http://www.sec.gov/CIK0001035688duration2010-01-01T00:00:002010-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3sem_DefinedContributionPlansDisclosuresLineItemssem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Retirement savings plan2false 4us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.250.25falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepurePercentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.No definition available.false0Matching contribution by the employer (as a percent)3false 4us-gaap_DefinedContributionPlanMaximumAnnualContributionPerEmployeePercentus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.060.06falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepureMaximum percentage of employee gross pay, by the terms of the plan, that the employer may contribute to a defined contribution plan.No definition available.false0Matching contribution of the employees (as a percent)4false 4sem_DefinedContributionPlanEmployersMatchingContributionVestingPeriodsem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse003 yearsfalsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:durationItemTypenaRepresents the vesting period of the employer's matching contributions to the defined contribution plan.No definition available.false0Vesting period5false 4us-gaap_DefinedContributionPlanCostRecognizedus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse82000008.2USD$falsetruefalse2truefalsefalse76000007.6USD$falsetruefalse3truefalsefalse60000006.0USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe amount of the cost recognized during the period for defined contribution plans.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 11 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Expense incurred6false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4false truefalseD2012_EmployeesOtherThanHighlyCompensatedEmployeesMember_MaximumMemberhttp://www.sec.gov/CIK0001035688duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseEmployees who are not classified as HCE'sus-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTitleOfIndividualAxisxbrldihttp://xbrl.org/2006/xbrldisem_EmployeesOtherThanHighlyCompensatedEmployeesMemberus-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTitleOfIndividualAxisexplicitMemberfalsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0Employees who are not classified as HCE's | Maximum7true 3sem_DefinedContributionPlansDisclosuresLineItemssem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Retirement savings plan8false 4sem_DefinedContributionPlanContributionPerEmployeePercentsem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.300.30falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepureRepresents the percentage of contribution by employees to a defined contribution plan.No definition available.false0Contribution by employees (as a percent)9false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse5false truefalseD2012_HighlyCompensatedEmployeesMember_MaximumMemberhttp://www.sec.gov/CIK0001035688duration2012-01-01T00:00:002012-12-31T00:00:00falsefalseHCEus-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTitleOfIndividualAxisxbrldihttp://xbrl.org/2006/xbrldisem_HighlyCompensatedEmployeesMemberus-gaap_DeferredCompensationArrangementWithIndividualPostretirementBenefitsByTitleOfIndividualAxisexplicitMemberfalsefalseMaximumus-gaap_RangeAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_MaximumMemberus-gaap_RangeAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0nanafalse0HCE | Maximum10true 3sem_DefinedContributionPlansDisclosuresLineItemssem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Retirement savings plan11false 4sem_DefinedContributionPlanContributionPerEmployeePercentsem_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.060.06falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalsenum:percentItemTypepureRepresents the percentage of contribution by employees to a defined contribution plan.No definition available.false0Contribution by employees (as a percent)falseRetirement Savings Plan (Details) (USD $)HundredThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.selectmedicalcorp.com/role/DisclosureRetirementSavingsPlanDetails311