Student Receivables - Changes in Current and Non-Current Receivables Allowance (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Receivables [Abstract]
Balance, Beginning of Period		$ 22,551	$ 24,153	$ 22,534	$ 23,142
Charges to Expense	[1]	6,730	6,918	13,743	15,210
Amounts Written-off		(5,013)	(6,497)	(12,009)	(13,778)
Balance, End of Period		$ 24,268	$ 24,574	$ 24,268	$ 24,574

[1] Charges to expense include an offset for recoveries of amounts previously written off of $1.2 million for each of the quarters ended June 30, 2018 and 2017, and $2.5 million and $2.7 million for the years to date ended June 30, 2018 and 2017, respectively.