Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Revenue	$ 72,196	$ 76,745	$ 147,884	$ 160,711
Costs and expenses:
Instructional costs and services	29,834	28,903	58,790	58,611
Selling and promotional	14,008	14,984	29,443	31,453
General and administrative	16,632	16,909	34,388	33,578
Loss on disposals of long-lived assets	678	464	1,168	725
Depreciation and amortization	4,726	4,825	9,470	9,714
Total costs and expenses	65,878	66,085	133,259	134,081
Income from operations before interest income and income taxes	6,318	10,660	14,625	26,630
Interest income	15	37	26	74
Income before income taxes	6,333	10,697	14,651	26,704
Income tax expense	2,525	4,172	6,374	10,439
Equity investment income	21	71	61	671
Net income	$ 3,829	$ 6,596	$ 8,338	$ 16,936
Net Income per common share:
Basic (in dollars per share)	$ 0.24	$ 0.41	$ 0.51	$ 1.06
Diluted (in dollars per share)	$ 0.23	$ 0.41	$ 0.51	$ 1.05
Weighted average number of common shares:
Basic (in shares)	16,240,955	16,059,358	16,214,304	16,048,977
Diluted (in shares)	16,360,177	16,195,713	16,339,919	16,155,176