Variable Interest Entities - Schedule of Fair Value and Carrying Value of Assets and Liabilities of the CUSO (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Variable Interest Entity [Line Items]
Restricted cash	$ 5,538	$ 6,015	$ 6,328
Current portion of CUSO Student Loans	9,787	8,480	9,541
CUSO Student Loans, excluding current portion, less allowance for loan losses of $2,412, $1,796 and $2,480	54,912	62,161	76,528
Total assets	622,391	663,654	739,247
Current portion of CUSO secured borrowing obligation	18,065	23,591	20,963
Other current liabilities	29,631	31,973	28,602
CUSO secured borrowing obligation, excluding current portion	89,695	91,728	96,226
Total liabilities	460,335	502,518	591,324
CUSO [Member]
Variable Interest Entity [Line Items]
Restricted cash	3,244	3,968	2,790
Current portion of CUSO Student Loans	4,251	2,734	3,066
CUSO Student Loans, excluding current portion, less allowance for loan losses of $2,412, $1,796 and $2,480	12,716	16,174	18,932
Other assets	285	257	202
Total assets	20,496	23,133	24,990
Current portion of CUSO secured borrowing obligation	18,065	23,591	20,963
Other current liabilities	153	154	182
CUSO secured borrowing obligation, excluding current portion	89,695	91,728	98,002
Total liabilities	$ 107,913	$ 115,473	$ 119,147