Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues	$ 680,153	$ 646,034	$ 591,732
Costs and expenses:
Operating	437,332	426,626	387,272
Selling	111,578	104,871	97,794
General and administrative	48,171	42,793	40,170
Depreciation	37,365	37,818	35,530
Amortization of intangible assets	1,742	1,908	1,791
Gain on sale of assets, net	(1,802)	(783)	(437)
Costs and Expenses	634,386	613,233	562,120
Income from operations	45,767	32,801	29,612
Other income (expense):
Interest expense	(2,698)	(3,794)	(2,803)
Interest income	200	43	46
Litigation settlement	0	(2,900)	0
Other	(2,611)	(2,850)	(2,521)
Income before income taxes	40,658	23,300	24,334
Income taxes	16,063	9,235	10,281
Net income	$ 24,595	$ 14,065	$ 14,053
Share data:
Earnings per share--basic:	$ 1.74	$ 1.00	$ 0.97
Earnings per share--diluted:	$ 1.68	$ 0.97	$ 0.93
Weighted-average shares outstanding:
Basic	14,102,366	14,006,093	14,511,100
Diluted	14,608,857	14,536,872	15,031,194
Dividends declared per share	$ 0.18	$ 0.17	$ 0.17