Student Receivables - Changes in Current and Non-Current Receivables Allowance (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Receivables [Abstract]
Balance, Beginning of Period		$ 24,836	$ 22,534
Charges to Expense	[1]	11,722	7,013
Amounts Written-off		(8,629)	(6,996)
Balance, End of Period		$ 27,929	$ 22,551

[1] Charges to expense include an offset for recoveries of amounts previously written off of $0.9 million and $1.3 million for the quarters ended March 31, 2019 and 2018, respectively.