Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income (loss)	$ (38,126)	$ 27,107
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Amortization of gain on sale of assets		(133)
Amortization of deferred rent	(1,362)	(1,351)
Amortization of deferred financing costs	209	197
Amortization of investment discount/premium	132
Depreciation and amortization	29,107	13,718
Deferred income taxes	(4,443)	(3,728)
Stock-based compensation	11,781	8,569
Fair value adjustments and impairment of intangible assets	19,304	(7,512)
Changes in assets and liabilities:
Tuition receivable, net	8,227	(454)
Other current assets	2,223	(2,155)
Other assets	(581)	1,200
Accounts payable and accrued expenses	(8,949)	9,711
Income taxes payable and income taxes receivable	(7,868)	(4,401)
Contract liabilities	(21,946)	5,386
Other long-term liabilities	(2,355)	(1,786)
Net cash provided by (used in) operating activities	(14,647)	44,368
Cash flows from investing activities:
Net cash acquired in acquisition	168,387
Purchases of property and equipment	(16,028)	(14,573)
Purchases of marketable securities	(11,346)
Maturities of marketable securities	5,842
Investments in partnership interests	(167)
Net cash (used in) provided by investing activities	146,688	(14,573)
Cash flows from financing activities:
Common dividends paid	(16,802)	(8,561)
Net proceeds from exercise of stock options	6,831
Taxes paid for restricted stock units	(459)
Payment of deferred financing costs	(1,162)
Net cash used in financing activities	(11,592)	(8,561)
Net increase in cash, cash equivalents, and restricted cash	120,449	21,234
Cash, cash equivalents, and restricted cash - beginning of period	156,448	129,758
Cash, cash equivalents, and restricted cash - end of period	276,897	150,992
Noncash transactions:
Purchases of property and equipment included in accounts payable	$ 2,975	$ 749