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v3.19.2

Segment Reporting - Additional Information (Details) | 6 Months Ended
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Jun. 30, 2019 segment
Segment Reporting [Abstract] |
Number of operating segments that meet threshold to qualify as reportable segments | 2

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- Definition Represents the number of operating segments that meet the quantitative thresholds to qualify as reportable segments. + References No definition available. + Details
Name: | stra_NumberOfOperatingSegmentsThatMeetThresholdToQualifyAsReportableSegments
Namespace Prefix: | stra_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_SegmentReportingAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration