Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Revenue	$ 313,139	$ 327,910	$ 350,020
Costs and expenses:
Instructional costs and services	117,013	118,848	123,765
Selling and promotional	59,095	62,397	69,229
General and administrative	68,666	73,047	74,958
Loss on disposals of long-lived assets	5,147	817	115
Loss on assets held for sale	823	0	0
Impairment of goodwill	4,735	0	0
Depreciation and amortization	19,384	20,520	16,121
Total costs and expenses	274,863	275,629	284,188
Income from continuing operations before interest income and income taxes	38,276	52,281	65,832
Interest income, net	116	115	361
Income from continuing operations before income taxes	38,392	52,396	66,193
Income tax expense	14,940	20,072	25,150
Equity investment income (loss)	703	90	(166)
Net income	$ 24,155	$ 32,414	$ 40,877
Net income per common share:
Basic (in dollars per share)	$ 1.50	$ 1.94	$ 2.36
Diluted (in dollars per share)	$ 1.49	$ 1.93	$ 2.33
Weighted average number of shares outstanding:
Basic (in shares)	16,068	16,676	17,357
Diluted (in shares)	16,214	16,798	17,543