Student Receivables - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Student receivables, net of allowance for doubtful accounts	$ 1,131	$ 942
Minimum [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Student receivables write-off period, days past due	90 days