Revision of 2011 and 2012 Financial Statements - Effect of Revisions on Affected Line Items on Consolidated Statement of Income (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Income Data:
Revenue	$ 267,173	$ 259,617	$ 260,459	$ 285,062	$ 305,572	$ 313,791	$ 328,061	$ 339,209	$ 1,072,311	$ 1,286,633	$ 1,499,977
Cost of educational services	118,432	120,204	123,541	124,176	129,394	133,948	140,067	134,941	486,353	538,350	553,065
Student services and administrative expenses	101,303	96,182	98,335	101,721	88,995	104,647	105,895	101,319	397,541	400,856	414,156
Settlement cost									(46,000)	21,750	0
Asset impairment					15,166	0	0	0	0	15,166	0
Legal and other investigation costs	3,121	2,089	213	1,500	0	0	873	0	6,923	873	0
Loss related to private student loan programs										0
Loss related to loan program guarantees	82,335	4,826	0	3,803	88,970	5,095	3,906	3,054	90,964	101,025	23,500
Total costs and expenses									1,011,130	1,056,270	990,721
Operating income	(46,666)	19,934	34,051	53,862	(16,953)	70,101	77,320	99,895	61,181	230,363	509,256
Income before provision for income taxes	(53,777)	12,760	26,707	(22,926)	(17,814)	69,205	76,568	100,029	(37,236)	227,988	510,333
Provision for income taxes	(14,396)	3,336	6,503	(5,655)	(7,740)	26,747	30,627	39,384	(10,212)	89,018	201,247
Net income	(39,381)	9,424	20,204	(17,271)	(10,074)	42,458	45,941	60,645	(27,024)	138,970	309,086
Earnings per share:
Basic	$ (1.68)	$ 0.40	$ 0.86	$ (0.74)	$ (0.44)	$ 1.82	$ 1.96	$ 2.39	$ (1.15)	$ 5.82	$ 11.27
Diluted	$ (1.68)	$ 0.40	$ 0.80	$ (0.63)	$ (0.44)	$ 1.81	$ 1.95	$ 2.37	$ (1.15)	$ 5.79	$ 11.18
As Previously Reported [Member]
Statement of Income Data:
Revenue										1,287,209	1,499,949
Cost of educational services										539,223	553,065
Student services and administrative expenses										422,345	439,808
Settlement cost										21,750
Asset impairment										0
Legal and other investigation costs										0
Loss related to private student loan programs										71,102
Loss related to loan program guarantees										0	0
Total costs and expenses										1,054,420	992,873
Operating income										232,789	507,076
Income before provision for income taxes										230,414	508,153
Provision for income taxes										89,949	200,401
Net income										140,465	307,752
Earnings per share:
Basic										$ 5.88	$ 11.22
Diluted										$ 5.85	$ 11.13
Revisions [Member]
Statement of Income Data:
Revenue										(576)	(28)
Cost of educational services										0	0
Student services and administrative expenses										(21,489)	(25,652)
Settlement cost										0
Asset impairment										0
Legal and other investigation costs										0
Loss related to private student loan programs										0
Loss related to loan program guarantees										23,339	23,500
Total costs and expenses										1,850	(2,152)
Operating income										(2,426)	2,180
Income before provision for income taxes										(2,426)	2,180
Provision for income taxes										(931)	846
Net income										(1,495)	1,334
Reclassifications [Member]
Statement of Income Data:
Revenue										0
Cost of educational services										(873)
Student services and administrative expenses										0
Settlement cost										(21,750)
Asset impairment										15,166
Legal and other investigation costs										873
Loss related to private student loan programs										(71,102)
Loss related to loan program guarantees										77,686
Total costs and expenses										0
Operating income										0
Income before provision for income taxes										0
Provision for income taxes										0
Net income										$ 0