Condensed Consolidated Balance Sheets - USD ($) $ in Thousands		Jun. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents, unrestricted		$ 87,343	$ 105,684
Restricted cash		4,000	4,000
Total cash, cash equivalents and restricted cash		91,343	109,684
Short-term investments		389,310	300,676
Total cash and cash equivalents, restricted cash and short-term investments		480,653	410,360
Student receivables, gross		91,457	84,599
Allowance for credit losses		(39,775)	(39,917)
Student receivables, net		51,682	44,682
Receivables, other		2,568	2,873
Prepaid expenses		10,986	8,209
Inventories		619	596
Other current assets		2,637	341
Total current assets		549,145	467,061
NON-CURRENT ASSETS:
Property and equipment, net of accumulated depreciation of $107,628 and $101,380 as of June 30, 2021 and December 31, 2020, respectively		24,807	27,761
Right of use asset, net		40,821	44,773
Goodwill		118,312	118,312
Intangible assets, net of amortization of $5,844 and $4,178 as of June 30, 2021 and December 31, 2020, respectively		13,856	15,522
Student receivables, gross		4,568	3,533
Allowance for credit losses		(3,101)	(2,230)
Student receivables, net		1,467	1,303
Deferred income tax assets, net		31,782	40,351
Other assets		6,229	6,434
TOTAL ASSETS	[1]	786,419	721,517
CURRENT LIABILITIES:
Lease liability-operating		9,779	9,789
Accounts payable		11,533	13,259
Accrued expenses:
Payroll and related benefits		19,495	22,661
Advertising and marketing costs		11,615	10,249
Income taxes		1,522	1,402
Other		18,614	11,921
Deferred revenue		45,214	34,534
Total current liabilities		117,772	103,815
NON-CURRENT LIABILITIES:
Lease liability-operating		40,565	43,405
Other liabilities		14,470	18,390
Total non-current liabilities		55,035	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; 87,884,843 and 87,264,910 shares issued, 70,082,105 and 70,062,364 shares outstanding as of June 30, 2021 and December 31, 2020, respectively		879	873
Additional paid-in capital		666,470	658,423
Accumulated other comprehensive income		20	364
Retained earnings		199,737	142,335
Treasury stock, at cost; 17,802,738 and 17,202,546 shares as of June 30, 2021 and December 31, 2020, respectively		(253,494)	(246,088)
Total stockholders' equity		613,612	555,907
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY		$ 786,419	$ 721,517

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