Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents, unrestricted		$ 86,031	$ 105,684
Restricted cash		4,000	4,000
Total cash, cash equivalents and restricted cash		90,031	109,684
Short-term investments		360,986	300,676
Total cash and cash equivalents, restricted cash and short-term investments		451,017	410,360
Student receivables, gross		82,592	84,599
Allowance for credit losses		(41,110)	(39,917)
Student receivables, net		41,482	44,682
Receivables, other		2,684	2,873
Prepaid expenses		10,023	8,209
Inventories		594	596
Other current assets		253	341
Total current assets		506,053	467,061
NON-CURRENT ASSETS:
Property and equipment, net of accumulated depreciation of $104,548 and $101,380 as of March 31, 2021 and December 31, 2020, respectively		25,696	27,761
Right of use asset, net		42,425	44,773
Goodwill		118,312	118,312
Intangible assets, net of amortization of $5,011 and $4,178 as of March 31, 2021 and December 31, 2020, respectively		14,689	15,522
Student receivables, gross		3,970	3,533
Allowance for credit losses		(2,675)	(2,230)
Student receivables, net		1,295	1,303
Deferred income tax assets, net		35,584	40,351
Other assets		6,311	6,434
TOTAL ASSETS	[1]	750,365	721,517
CURRENT LIABILITIES:
Lease liability-operating		9,677	9,789
Accounts payable		10,767	13,259
Accrued expenses:
Payroll and related benefits		15,207	22,661
Advertising and marketing costs		11,643	10,249
Income taxes		6,627	1,402
Other		12,294	11,921
Deferred revenue		37,004	34,534
Total current liabilities		103,219	103,815
NON-CURRENT LIABILITIES:
Lease liability-operating		40,423	43,405
Other liabilities		18,378	18,390
Total non-current liabilities		58,801	61,795
STOCKHOLDERS' EQUITY:
Preferred stock, $0.01 par value; 1,000,000 shares authorized; none issued or outstanding
Common stock, $0.01 par value; 300,000,000 shares authorized; 87,795,103 and 87,264,910 shares issued, 70,432,568 and 70,062,364 shares outstanding as of March 31, 2021 and December 31, 2020, respectively		878	873
Additional paid-in capital		662,485	658,423
Accumulated other comprehensive income		14	364
Retained earnings		173,088	142,335
Treasury stock, at cost; 17,362,535 and 17,202,546 shares as of March 31, 2021 and December 31, 2020, respectively		(248,120)	(246,088)
Total stockholders' equity		588,345	555,907
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY		$ 750,365	$ 721,517

[1] Total assets do not include intercompany receivable or payable activity between institutions and corporate and investments in subsidiaries.