Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 67,888	$ 72,992	$ 211,889	$ 220,757
Costs and expenses:
Instructional costs and services	27,268	28,186	83,908	86,839
Selling and promotional	15,873	14,139	45,007	43,004
General and administrative	22,021	19,298	59,209	55,780
Loss on disposals of long-lived assets	394	196	524	882
Impairment of goodwill	1,481	0	7,336	0
Depreciation and amortization	3,764	4,289	11,758	13,158
Total costs and expenses	70,801	66,108	207,742	199,663
(Loss) income from operations before interest income and income taxes	(2,913)	6,884	4,147	21,094
Interest income, net	1,019	774	3,207	1,928
(Loss) income before income taxes	(1,894)	7,658	7,354	23,022
Income tax (benefit) expense	(239)	1,848	1,596	5,993
Equity investment income (loss)	17	(311)	(1,464)	(483)
Net (loss) income	$ (1,638)	$ 5,499	$ 4,294	$ 16,546
Net (loss) income per common share:
Basic (in dollars per share)	$ (0.10)	$ 0.33	$ 0.26	$ 1.01
Diluted (in dollars per share)	$ (0.10)	$ 0.33	$ 0.26	$ 1.00
Weighted average number of common shares:
Basic (in shares)	15,966,789	16,423,548	16,335,097	16,397,483
Diluted (in shares)	16,120,779	16,658,159	16,486,837	16,627,532