Consolidated Statements of Cash Flow (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net income	$ 22,853	$ 24,595	$ 14,065
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	38,231	37,365	37,818
Amortization	1,980	1,742	1,908
Gain on sale of assets	(1,294)	(1,802)	(783)
Deferred income taxes	1,716	(3,607)	3,428
Other	(3,228)	3,493	(1,501)
Changes in operating assets and liabilities:
Accounts receivable	10,307	(24,294)	(10,347)
Accounts payable and accrued expenses	(2,308)	(1,145)	6,152
Self-insurance accruals	(5,021)	4,468	2,855
Other assets, net	(6,926)	3,121	827
Adjustments to reconcile net income to net cash provided by operating activities	33,457	19,341	40,357
Net cash provided by operating activities	56,310	43,936	54,422
Capital expenditures:
Equipment	(42,462)	(29,294)	(34,370)
Land and buildings	(2,743)	(440)	(331)
Proceeds from sales of property and equipment	2,080	2,955	1,535
Purchases of businesses	(80)	(4,400)	(962)
Net cash used in investing activities	(43,205)	(31,179)	(34,128)
Financing activities
Revolving credit facility borrowings/(payments), net	(4,200)	4,200	(10,000)
Borrowings/(payments) of notes payable	1,442	1,155	(1,821)
Payments of long-term debt and capital leases	(583)	(649)	(955)
Purchase of common shares for treasury	(21,887)	(18,103)	(14,222)
Sale of common shares from treasury	9,582	10,735	7,316
Cash received on common-share subscriptions	1,285	1,841	0
Dividends	(2,530)	(2,556)	(2,362)
Net cash used in financing activities	(16,891)	(3,377)	(22,044)
Increase (Decrease) in cash and cash equivalents	(3,786)	9,380	(1,750)
Cash and cash equivalents, beginning of year	19,647	10,267	12,017
Cash and cash equivalents, end of year	$ 15,861	$ 19,647	$ 10,267