Other Long-Term Liabilities - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2020	Dec. 31, 2019
Other Liabilities, Noncurrent [Abstract]
Deferred payment arrangements value	$ 1.4	$ 2.2
Funds received from investor	$ 2.8

The value of the deferred payment arrangement with one of the sellers in connection with an acquisition.

No definition available.

Name:	stra_DeferredPaymentArrangementValue
Namespace Prefix:	stra_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant