CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 22,013,000	$ 14,624,000
Short-term investments	16,583,000	40,250,000
Accounts receivable, net of allowance for doubtful accounts of $250 at December 31, 2017 and 2016	33,138,000	16,031,000
Current maturities of notes receivable	695,000
Prepaid expenses and other current assets	4,677,000	4,822,000
Total current assets	77,106,000	75,727,000
Property and equipment	307,844,000	324,950,000
Less accumulated depreciation	(221,271,000)	(214,033,000)
Property and equipment, net	86,573,000	110,917,000
Notes receivable, net of current maturities	841,000
Intangibles, net	494,000	487,000
Long-term deferred tax assets, net	224,000	535,000
Total assets	165,238,000	187,666,000
Current liabilities:
Accounts payable	5,933,000	5,617,000
Accrued liabilities:
Payroll costs and other taxes	1,151,000	885,000
Other	4,314,000	2,983,000
Deferred revenue	3,699,000	3,155,000
Current maturities of notes payable and obligations under capital leases	2,712,000	2,357,000
Total current liabilities	17,809,000	14,997,000
Long-term liabilities:
Notes payable and obligations under capital leases, net of current maturities	5,153,000
Deferred tax liabilities, net	874,000	146,000
Other accrued liabilities	150,000	1,639,000
Total long-term liabilities	6,177,000	1,785,000
Commitments and contingencies
Stockholders' equity:
Preferred stock-par value $1.00 per share; 4,000,000 shares authorized, none outstanding
Common stock-par value $0.01 per share; 35,000,000 shares authorized, 21,836,617 and 21,704,851 shares issued, and 21,788,172 and 21,656,406 shares outstanding at December 31, 2017 and 2016, respectively	218,000	217,000
Additional paid-in capital	143,835,000	142,998,000
Retained (deficit) earnings	(2,021,000)	29,265,000
Treasury stock, at cost; 48,445 shares at December 31, 2017 and December 31, 2016
Accumulated other comprehensive loss, net	(780,000)	(1,596,000)
Total stockholders' equity	141,252,000	170,884,000
Total liabilities and stockholders' equity	$ 165,238,000	$ 187,666,000

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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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.