Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
OPERATING ACTIVITIES:
Net income	$ 4,619	$ 2,490
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	29,536	28,193
Bad debt expense (recovery)	496	(224)
Stock compensation-net of excess tax benefits	315	303
Provision for deferred income taxes	2,972	1,638
Reclassification of other than temporary impairment in marketable equity securities	29	63
Recognized gain on sale of marketable equity securities	(24)	(1,985)
Gain on sale or disposal of equipment	(823)	(90)
Changes in operating assets and liabilities:
Accounts receivable	(11,075)	(6,405)
Prepaid expenses, deposits, inventories, and other assets	4,159	576
Income taxes receivable	(16)	(134)
Trade accounts payable	1,810	1,871
Accrued expenses and other liabilities	4,016	1,950
Net cash provided by operating activities	36,014	28,246
INVESTING ACTIVITIES:
Purchases of property and equipment	(55,694)	(66,003)
Proceeds from disposition of equipment	24,525	14,114
Change in restricted cash	(3,650)	(41)
Sales of marketable equity securities	13	3,558
Purchases of marketable equity securities, net of return of capital	22	(70)
Net cash used in investing activities	(34,784)	(48,442)
FINANCING ACTIVITIES:
Borrowings under line of credit	315,222	324,104
Repayments under line of credit	(320,639)	(327,238)
Borrowings of long-term debt	30,802	45,422
Repayments of long-term debt	(25,881)	(17,829)
Borrowings under margin account	103	8,908
Repayments under margin account	(626)	(4,015)
Repurchases of common stock	(470)
Dividends paid		(8,702)
Exercise of stock options	19	55
Net cash (used) provided by financing activities	(1,470)	20,705
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(240)	509
CASH AND CASH EQUIVALENTS-Beginning of period	507	180
CASH AND CASH EQUIVALENTS-End of period	267	689
Cash paid during the period for:
Interest	2,578	1,812
Income taxes	62	169
NONCASH INVESTING AND FINANCING ACTIVITIES-
Purchases of property and equipment included in accounts payable	$ 422	$ 6,707