Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 9,467	$ 10,578
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of gain on sale of assets		(71)
Amortization of deferred rent	(417)	(477)
Amortization of deferred financing costs	66	66
Depreciation and amortization	5,035	4,370
Deferred income taxes	(1,842)	762
Stock-based compensation	2,688	2,427
Changes in assets and liabilities:
Tuition receivable, net	(2,249)	19
Other current assets	931	616
Other assets	115	397
Accounts payable and accrued expenses	(867)	(2,836)
Income taxes payable and income taxes receivable	3,995	7,089
Contract liabilities	1,192	2,441
Other long-term liabilities	(1,065)	(846)
Net cash provided by operating activities	17,049	24,535
Cash flows from investing activities:
Purchases of property and equipment	(4,233)	(3,841)
Net cash used in investing activities	(4,233)	(3,841)
Cash flows from financing activities:
Common dividends paid	(2,889)	(2,853)
Net cash used in financing activities	(2,889)	(2,853)
Net increase in cash and cash equivalents	9,927	17,841
Cash, cash equivalents, and restricted cash - beginning of period	156,448	129,758
Cash, cash equivalents, and restricted cash - end of period	166,375	147,599
Noncash transactions:
Purchases of property and equipment included in accounts payable	$ 2,385	$ 571