Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 165,867	$ 155,933
Tuition receivable, net	24,997	23,122
Other current assets	10,558	11,293
Total current assets	201,422	190,348
Property and equipment, net	73,686	73,763
Deferred income taxes	23,803	24,452
Goodwill	20,744	20,744
Other assets	12,155	11,971
Total assets	331,810	321,278
Current liabilities:
Accounts payable and accrued expenses	45,806	46,177
Income taxes payable	2,541	1,038
Contract liabilities	23,931	21,851
Total current liabilities	72,278	69,066
Other long-term liabilities	41,240	43,015
Total liabilities	113,518	112,081
Commitments and contingencies
Stockholders' equity:
Common stock, par value $0.01; 20,000,000 shares authorized; 11,167,425 and 11,300,671 shares issued and outstanding at December 31, 2017 and March 31, 2018, respectively	113	112
Additional paid-in capital	49,766	47,079
Retained earnings	168,413	162,006
Total stockholders' equity	218,292	209,197
Total liabilities and stockholders' equity	$ 331,810	$ 321,278

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.