XML 54 R41.htm IDEA: XBRL DOCUMENT v3.20.2
Revenue Recognition - Additional Information (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Revenue Recognition [Line Items]          
Length of academic year     210 days    
Revenue recognized estimated reserve based on historical evidence $ 1.2   $ 1.2   $ 1.1
ASC Topic 606 [Member]          
Revenue Recognition [Line Items]          
Revenue recognized for payments received from withdrawn students $ 0.3 $ 0.3 $ 0.6 $ 0.5  
Minimum [Member]          
Revenue Recognition [Line Items]          
Length of academic terms     56 days    
Maximum [Member]          
Revenue Recognition [Line Items]          
Length of academic terms     84 days