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Revenue - Additional Information (Details) - USD ($)
Mar. 31, 2020
Dec. 31, 2019
Mar. 31, 2019
Revenue from Contract with Customer [Abstract]      
Contract assets $ 0 $ 0  
Deferred revenue 19,974,000 17,426,000  
Future revenue 11,800,000 9,600,000  
Student deposits 8,200,000 $ 7,800,000  
Interest receivable $ 4,000   $ 5,000