Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 147,652	$ 95,867	$ 109,637
Adjustments to reconcile net income to net
Asset impairment	14,263	2,994
Gain on sale of asset	(22,086)
Depreciation and amortization expense	16,887	19,734	16,766
Bad debt expense	33,215	41,574	44,344
Compensation expense related to share-based awards	8,078	8,751	14,972
Deferred income taxes	3,761	(720)	15,330
Changes in operating assets and liabilities:
Student receivables, gross	15,929	6,380	6,631
Allowance for credit losses	(38,573)	(38,992)	(47,417)
Receivables, other	(3,922)	(1,670)	5,396
Inventories, prepaid expenses, and other current assets	(2,994)	2,640	3,285
Other non-current assets	478	843	72
Accounts payable	(4,878)	1,922	(2,744)
Accrued expenses and other non-current liabilities	(19,235)	22,332	(3,404)
Deferred revenue	(34,375)	(11,767)	30,724
Right of use asset and lease liability	(2,175)	(1,702)	(2,476)
Net cash provided by operating activities	112,025	148,186	191,116
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of available-for-sale investments	(314,279)	(492,100)	(269,739)
Sales of available-for-sale investments	238,184	262,277	391,659
Purchases of property and equipment	(6,411)	(12,620)	(10,453)
Business acquisitions, net of cash acquired		(84,308)	(57,143)
Earnout payment related to business acquisition	(6,000)
Net cash (used in) provided by investing activities	(88,506)	(326,751)	54,324
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchase of treasury stock	(8,301)	(23,117)	(25,296)
Issuance of common stock	2,545	1,197	861
Payments of employee tax associated with stock compensation	(2,209)	(1,612)	(5,511)
Payments of cash dividends	(14,417)
Release of cash held in escrow	(1,000)	(4,197)
Net cash used in financing activities	(23,382)	(27,729)	(29,946)
NET INCREASE (DECREASE) IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	137	(206,294)	215,494
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of the year	118,884	325,178	109,684
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of the year	119,021	118,884	325,178
Supplemental Cash Flow Information:
Income taxes paid	41,763	28,940	23,224
Supplemental Non-Cash Disclosures:
Amount placed in escrow to secure indemnification obligations from business acquisitions		8,500	1,210
Non-cash additions to property and equipment	$ 329	$ (1,953)	2,287
Right of use assets obtained in exchange for lease liabilities			$ 727