Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 375,515	$ 311,732
Marketable securities	39,288	37,121
Tuition receivable, net	47,340	55,694
Income taxes receivable	10,518	0
Other current assets	17,660	15,814
Total current assets	490,321	420,361
Property and equipment, net	118,462	122,677
Right-of-use lease assets	97,484
Marketable securities, non-current	25,737	37,678
Intangible assets, net	300,678	328,344
Goodwill	732,104	732,540
Other assets	19,784	19,429
Total assets	1,784,570	1,661,029
Current liabilities:
Accounts payable and accrued expenses	86,066	85,979
Income taxes payable	0	419
Contract liabilities	40,919	38,733
Lease liabilities	26,834
Total current liabilities	153,819	125,131
Deferred income tax liabilities	66,323	59,358
Lease liabilities, non-current	86,998
Other long-term liabilities	39,554	51,316
Total liabilities	346,694	235,805
Commitments and contingencies
Stockholders’ equity:
Common stock, par value $0.01; 32,000,000 shares authorized; 21,743,498 and 21,948,563 shares issued and outstanding at December 31, 2018 and June 30, 2019, respectively	219	217
Additional paid-in capital	1,305,148	1,306,653
Accumulated other comprehensive income	449	32
Retained earnings	132,060	118,322
Total stockholders’ equity	1,437,876	1,425,224
Total liabilities and stockholders’ equity	$ 1,784,570	$ 1,661,029