CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OPERATING ACTIVITIES
Net income (loss)	$ 15,811	$ (7,732)	$ 6,333
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	84,215	85,493	73,742
Amortization of intangibles	4,174	2,261	0
Pension settlement expense	2,111	0	1,125
Share-based compensation expense	5,494	6,068	6,450
Provision for losses on accounts receivable	2,065	1,524	2,394
Deferred income tax provision (benefit)	(10,367)	(10,359)	3,056
Gain on sale of property and equipment	(153)	(735)	(2,360)
Changes in operating assets and liabilities:
Receivables	(24,200)	508	(6,067)
Prepaid expenses	(1,670)	305	(1,105)
Other assets	(1,015)	961	(635)
Income taxes	8,468	2,630	(776)
Accounts payable, accrued expenses, and other liabilities	8,571	3,610	18,695
NET CASH PROVIDED BY OPERATING ACTIVITIES	93,504	84,534	100,852
INVESTING ACTIVITIES
Purchases of property, plant and equipment, net of financings	(26,369)	(37,278)	(53,227)
Proceeds from sale of property and equipment	2,194	6,397	7,062
Purchases of short-term investments	(39,605)	(55,858)	(59,718)
Proceeds from sale of short-term investments	32,718	60,730	64,995
Business acquisition, net of cash acquired	(4,146)	(180,039)	0
Capitalization of internally developed software and other	(7,668)	(7,218)	(5,295)
NET CASH USED IN INVESTING ACTIVITIES	(42,876)	(213,266)	(46,183)
FINANCING ACTIVITIES
Borrowings under credit facilities	0	100,000	0
Payments on long-term debt	(43,176)	(53,000)	(16,056)
Acquisition of noncontrolling interest	0	0	(4,084)
Net change in bank overdraft and other	(37)	(7,190)	7,811
Net change in restricted cash, cash equivalents, and short-term investments	7,756	43,035	(1,032)
Deferred financing costs	(71)	(1,487)	(174)
Payment of common stock dividends	(3,233)	(3,219)	(3,180)
Proceeds from the exercise of stock options	2,785	0	763
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(35,976)	78,139	(15,952)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	14,652	(50,593)	38,717
Cash and cash equivalents at beginning of period	90,702	141,295	102,578
CASH AND CASH EQUIVALENTS AT END OF PERIOD	105,354	90,702	141,295
NONCASH INVESTING ACTIVITIES
Accruals for equipment received	324	301	338
Equipment financed under notes payable and capital leases	$ 36	$ 37,973	$ 30,410