Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
OPERATING ACTIVITIES:
Net income	$ 2,226	$ 1,609
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	19,860	18,554
Bad debt expense	420	2
Stock compensation-net of excess tax benefits	276	254
Provision for deferred income taxes	1,406	986
Reclassification of unrealized loss on marketable equity securities	27	44
Recognized gain on sale of marketable equity securities	(27)	(1,043)
Gain on sale or disposal of equipment	(355)	(243)
Changes in operating assets and liabilities:
Accounts receivable	(11,263)	(5,617)
Prepaid expenses, deposits, inventories, and other assets	4,094	2,617
Income taxes payable	(10)	(71)
Trade accounts payable	3,548	3,346
Accrued expenses and other liabilities	3,823	1,923
Net cash provided by operating activities	24,025	22,361
INVESTING ACTIVITIES:
Purchases of property and equipment	(40,545)	(42,986)
Proceeds from disposition of equipment	13,879	10,936
Change in restricted cash	(2,973)	771
Sales of marketable equity securities	13	2,152
Purchases of marketable equity securities, net of return of capital	11	45
Net cash used in investing activities	(29,615)	(29,082)
FINANCING ACTIVITIES:
Borrowings under line of credit	209,926	209,827
Repayments under line of credit	(206,986)	(219,156)
Borrowings of long-term debt	22,177	35,498
Repayments of long-term debt	(19,171)	(13,479)
Borrowings under margin account	78	8,773
Repayments under margin account	(406)	(2,392)
Repurchases of common stock	(470)
Dividends paid		(8,702)
Exercise of stock options		55
Net cash provided by financing activities	5,148	10,424
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(442)	3,703
CASH AND CASH EQUIVALENTS - Beginning of period	507	180
CASH AND CASH EQUIVALENTS - End of period	65	3,883
Cash paid during the period for:
Interest	1,722	1,190
Income taxes	46	158
NONCASH INVESTING AND FINANCING ACTIVITIES-
Purchases of property and equipment included in accounts payable	$ 10,966	$ 4,231