Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Summary of Significant Accounting Policies
Revenues	$ 376,145	$ 257,559	$ 747,105	$ 514,680
School operating losses included in the entity's revenue	24,200	11,200	$ 44,200	27,500
Minimum
Summary of Significant Accounting Policies
Duration of contracts providing access to curriculum via the entity's Web site			1 year
Maximum
Summary of Significant Accounting Policies
Duration of contracts providing access to curriculum via the entity's Web site			2 years
Primary Obligor
Summary of Significant Accounting Policies
Revenues	$ 102,400	$ 83,900	$ 212,100	$ 169,400