Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 20,612	$ 34,802	$ 40,023
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of gain on sale of assets	(133)	(281)	(280)
Amortization of deferred rent	(1,780)	(1,441)	(345)
Amortization of deferred financing costs	262	262	1,229
Depreciation and amortization	18,733	17,817	18,104
Deferred income taxes	6,429	(8,697)	(4,006)
Stock-based compensation	11,627	10,767	10,213
Changes in assets and liabilities:
Tuition receivable, net	(3,250)	(1,453)	(1,991)
Other current assets	(527)	(3,949)	4,005
Other assets	1,582	(1,865)	22
Accounts payable and accrued expenses	4,468	(262)	(752)
Income taxes payable and income taxes receivable	(629)	(408)	1,835
Deferred revenue	8,212	7,018	12,465
Other long-term liabilities	(9,451)	(7,800)	(2,974)
Net cash provided by operating activities	56,155	44,510	77,548
Cash flows from investing activities:
Purchases of property and equipment	(18,051)	(13,161)	(12,692)
Cash used in acquisition, net of cash acquired		(7,635)
Net cash used in investing activities	(18,051)	(20,796)	(12,692)
Cash flows from financing activities:
Common dividends paid	(11,416)
Payments on term loan			(118,750)
Payments of contingent consideration		(1,358)	(650)
Payment of deferred financing costs			(850)
Net cash used in financing activities	(11,416)	(1,358)	(120,250)
Net increase in cash and cash equivalents	26,688	22,356	(55,394)
Cash and cash equivalents - beginning of year	129,245	106,889	162,283
Cash and cash equivalents - end of year	155,933	129,245	106,889
Noncash transactions:
Purchases of property and equipment included in accounts payable	$ 1,734	$ 349	$ 365