CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
OPERATING ACTIVITIES
Net income (loss)	$ (7,732)	$ 6,333	$ (32,421)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	85,493	73,742	71,565
Amortization of intangibles	2,261
Pension settlement expense		1,125	178
Share-based compensation expense	6,068	6,450	5,690
Provision for losses on accounts receivable	1,524	2,394	868
Deferred income tax provision (benefit)	(10,359)	3,056	(11,457)
Gain on sale of property and equipment	(735)	(2,360)	(981)
Changes in operating assets and liabilities:
Receivables	508	(6,067)	(32,211)
Prepaid expenses	305	(1,105)	144
Other assets	961	(635)	(1,568)
Income taxes	2,630	(776)	21,016
Accounts payable, accrued expenses, and other liabilities	3,610	18,695	5,464
NET CASH PROVIDED BY OPERATING ACTIVITIES	84,534	100,852	26,287
INVESTING ACTIVITIES
Purchases of property, plant and equipment, net of financings	(37,278)	(53,227)	(11,422)
Proceeds from sale of property and equipment	6,397	7,062	5,879
Purchases of short-term investments	(55,858)	(59,718)	(65,171)
Proceeds from sale of short-term investments	60,730	64,995	119,744
Business acquisition, net of cash acquired	(180,039)
Capitalization of internally developed software and other	(7,218)	(5,295)	(4,355)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(213,266)	(46,183)	44,675
FINANCING ACTIVITIES
Proceeds from issuance of long-term debt	100,000		11,416
Payments on long-term debt	(53,000)	(16,056)	(8,077)
Acquisition of noncontrolling interest		(4,084)
Net change in bank overdraft and other	(7,190)	7,811	(8,918)
Net change in restricted cash equivalents and short-term investments	43,035	(1,032)	(804)
Deferred financing costs	(1,487)	(174)	(35)
Payment of common stock dividends	(3,219)	(3,180)	(3,126)
Proceeds from the exercise of stock options		763	1,828
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	78,139	(15,952)	(7,716)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(50,593)	38,717	63,246
Cash and cash equivalents at beginning of period	141,295	102,578	39,332
CASH AND CASH EQUIVALENTS AT END OF PERIOD	90,702	141,295	102,578
NONCASH INVESTING ACTIVITIES
Accruals for equipment received	301	338
Equipment financed under capital leases and notes payable	$ 37,973	$ 30,410	$ 36,343