Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows provided by operating activities:
Net income	$ 58,078	$ 78,112
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation	3,190	3,019
Depreciation and amortization	5,724	5,426
Amortization of intangible assets	2,105	2,105
Deferred income taxes	1,480	1,776
Other, including fixed asset impairments	719	65
Changes in assets and liabilities:
Accounts receivable and interest receivable from university partners	(31,943)	(29,601)
Other assets	(5,312)	(6,166)
Right-of-use assets and lease liabilities	179	165
Accounts payable	5,427	971
Accrued liabilities	2,377	10,714
Income taxes receivable/payable	16,074	16,305
Deferred revenue	12,162	6,936
Net cash provided by operating activities	70,260	89,827
Cash flows used in investing activities:
Capital expenditures	(6,784)	(8,911)
Additions of amortizable content	(95)	(90)
Purchases of investments	(62,834)	(31,337)
Proceeds from sale or maturity of investments		5,519
Net cash used in investing activities	(69,713)	(34,819)
Cash flows (used in) provided by financing activities:
Principal payments on notes payable		(8,286)
Repurchase of common shares including shares withheld in lieu of income taxes	(399,555)	(69,342)
Net proceeds from exercise of stock options		2,680
Net cash used in financing activities	(399,555)	(74,948)
Net decrease in cash and cash equivalents and restricted cash	(399,008)	(19,940)
Cash and cash equivalents and restricted cash, beginning of period	600,941	245,769
Cash and cash equivalents and restricted cash, end of period	201,933	225,829
Supplemental disclosure of cash flow information
Cash paid for interest		895
Cash paid for income taxes	306	230
Supplemental disclosure of non-cash investing and financing activities
Purchases of property and equipment included in accounts payable	1,442	876
ROU Asset and Liability recognition	$ 1,980	$ 1,586