CONSOLIDATED STATEMENTS OF INCOME (unaudited) (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
Income Statement [Abstract]
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
Costs and expenses:
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
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 loan program guarantees	82,335	4,826	0	3,803	88,970	5,095	3,906	3,054	90,964	101,025	23,500
Provision for PEAKS Trust student loan losses	8,648	16,382	4,319	0					29,349	0	0
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
(Loss) on consolidation of PEAKS Trust	0	0	0	(73,248)					(73,248)	0	0
Interest income	33	16	25	34	40	125	502	681	108	1,348	2,902
Interest (expense)	(7,144)	(7,190)	(7,369)	(3,574)	(901)	(1,021)	(1,254)	(547)	(25,277)	(3,723)	(1,825)
Income (loss) 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 (loss)	$ (39,381)	$ 9,424	$ 20,204	$ (17,271)	$ (10,074)	$ 42,458	$ 45,941	$ 60,645	$ (27,024)	$ 138,970	$ 309,086
Earnings (loss) 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
Weighted average shares outstanding:
Basic									23,412	23,880	27,429
Diluted									23,412	23,999	27,655