UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 9,577	$ 35,239
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred financing costs	138	83
Amortization of investment discount/premium	24	65
Depreciation and amortization	34,571	25,733
Deferred income taxes	(8,898)	(2,108)
Stock-based compensation	3,900	3,025
Impairment of right-of-use lease assets	14,388	453
Changes in assets and liabilities:
Tuition receivable, net	(13,417)	3,553
Other assets	(9,897)	(3,090)
Accounts payable and accrued expenses	(10,276)	(7,028)
Income taxes payable and income taxes receivable	12,777	12,314
Contract liabilities	46,872	1,901
Other liabilities	(978)	(1,445)
Net cash provided by operating activities	78,781	68,695
Cash flows from investing activities:
Purchases of property and equipment	(12,650)	(14,258)
Purchases of marketable securities	0	(1,863)
Proceeds from marketable securities	1,930	9,905
Other investments	(72)	(118)
Net cash used in investing activities	(10,792)	(6,334)
Cash flows from financing activities:
Common dividends paid	(14,778)	(13,327)
Net payments for stock awards	(2,326)	(25,089)
Repurchase of common stock	0	(247)
Net cash used in financing activities	(17,104)	(38,663)
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(866)	0
Net increase in cash, cash equivalents, and restricted cash	50,019	23,698
Cash, cash equivalents, and restricted cash — beginning of period	202,020	420,497
Cash, cash equivalents, and restricted cash — end of period	252,039	444,195
Noncash transactions:
Non-cash additions to property and equipment	7,526	1,392
Right-of-use lease assets obtained in exchange for operating lease liabilities	$ 46,147	$ 3,504