Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 10,013,000	$ 25,639,000	$ 21,121,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,596,000	17,501,000	18,776,000
Stock-based compensation	5,960,000	7,180,000	6,246,000
Equity investment loss	1,464,000	515,000	2,430,000
Deferred income taxes	(1,973,000)	(917,000)	(2,494,000)
Loss on disposals of long-lived assets	556,000	882,000	2,093,000
Impairment of goodwill	7,336,000	0	0
Other	145,000	302,000	353,000
Changes in operating assets and liabilities:
Accounts receivable, net of allowance for bad debt	2,734,000	(6,923,000)	(187,000)
Prepaid expenses	(1,149,000)	(560,000)	571,000
Income tax receivable	(859,000)	(898,000)	0
Operating lease assets, net	120,000
Other assets	550,000	71,000	(653,000)
Accounts payable	(5,564,000)	266,000	1,991,000
Accrued compensation and benefits	653,000	3,298,000	(1,455,000)
Accrued liabilities	3,672,000	875,000	(740,000)
Income tax payable	0	(1,710,000)	1,151,000
Deferred revenue and student deposits	(884,000)	(1,342,000)	(1,265,000)
Net cash provided by operating activities	38,370,000	44,179,000	47,938,000
Investing activities
Capital expenditures	(7,255,000)	(9,430,000)	(14,788,000)
Proceeds from the sale of real property	0	0	1,493,000
Equity investments	0	0	(300,000)
Net cash used in investing activities	(7,255,000)	(9,430,000)	(13,595,000)
Financing activities
Cash paid for repurchase of common/restricted stock	(40,506,000)	(1,823,000)	(1,587,000)
Cash received from issuance of common stock	0	0	98,000
Net cash used in financing activities	(40,506,000)	(1,823,000)	(1,489,000)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(9,391,000)	32,926,000	32,854,000
Cash, cash equivalents, and restricted cash at beginning of period	212,131,000	179,205,000	146,351,000
Cash, cash equivalents, and restricted cash at end of period	202,740,000	212,131,000	179,205,000
Supplemental disclosures of cash flow information
Income taxes paid	$ 8,019,000	$ 12,712,000	$ 12,836,000