XML 74 R60.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Other Employee Benefit Plans (Details) - USD ($) |  | 12 Months Ended
--- | --- | ---
Jan. 01, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Percentage of company matching contribution to 401(K) plan |  | 50.00% |  |
Defined contribution plan employer matching contribution percent |  | 3.00% |  |
Company's contributions to 401(K) plan |  | $ 1,300,000 | $ 1,100,000 | $ 1,100,000
Common stock shares purchase price limit for employees as percentage of market value under Employee Stock Purchase Plan |  | 90.00% |  |
Employee stock purchase plan maximum percentage of purchase employee can make on eligible compensation |  | 10.00% |  |
Maximum number of shares available for purchase by participating employees |  | 2,500,000 |  |
Forecast |  |  |  |
Maximum annual contribution to 401(k) plan by employees, effective January 1, 2017 | $ 18,500 |  |  |

X
- Definition Employee stock purchase plan, maximum percentage of purchase an employee can make on eligible compensation. + References No definition available. + Details
Name: | stra_EmployeeStockPurchasePlanMaximumPercentageOfPurchaseEmployeeCanMakeOnEligibleCompensation
Namespace Prefix: | stra_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Employee stock purchase plan, percentage of purchase price from market value. + References No definition available. + Details
Name: | stra_EmployeeStockPurchasePlanPercentageOfPurchasePriceFromMarketValue
Namespace Prefix: | stra_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of discretionary contributions made by an employer to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage employer matches of the employee's percentage contribution matched. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum amount the employee may contribute to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This item represents the number of shares provided to the Employee Stock Ownership Plan (ESOP) during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 40 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=65895303&loc=d3e17540-113929 + Details
Name: | us-gaap_EmployeeStockOwnershipPlanESOPSharesContributedToESOP
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |