CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES
Net income	$ 31,633	$ 5,465
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	60,613	64,439
Amortization of intangibles	3,242	3,130
Pension settlement expense	5,405	1,834
Share-based compensation expense	5,362	3,579
Provision for losses on accounts receivable	1,647	1,658
Deferred income tax benefit	(7,409)	(5,770)
Gain on sale of property and equipment	(597)	(486)
Changes in operating assets and liabilities:
Receivables	(41,180)	(36,513)
Prepaid expenses	1,477	1,768
Other assets	(1,081)	(1,557)
Income taxes	9,981	6,868
Accounts payable, accrued expenses, and other liabilities	49,108	21,836
NET CASH PROVIDED BY OPERATING ACTIVITIES	118,201	66,251
INVESTING ACTIVITIES
Purchases of property, plant and equipment, net of financings	(23,756)	(13,078)
Proceeds from sale of property and equipment	2,701	1,857
Purchases of short-term investments	(25,347)	(21,230)
Proceeds from sale of short-term investments	17,478	21,713
Business acquisitions, net of cash acquired	(2,647)	(4,146)
Capitalization of internally developed software	(6,016)	(5,959)
NET CASH USED IN INVESTING ACTIVITIES	(37,587)	(20,843)
FINANCING ACTIVITIES
Payments on long-term debt	(28,024)	(31,775)
Net change in bank overdraft	2,304	(2,002)
Net change in restricted cash, cash equivalents, and short-term investments	517	7,757
Deferred financing costs	(61)	(61)
Payment of common stock dividends	(2,458)	(2,418)
Proceeds from the exercise of stock options	1,136
NET CASH USED IN FINANCING ACTIVITIES	(26,586)	(28,499)
NET INCREASE IN CASH AND CASH EQUIVALENTS	54,028	16,909
Cash and cash equivalents at beginning of period	105,354	90,702
CASH AND CASH EQUIVALENTS AT END OF PERIOD	159,382	107,611
NONCASH INVESTING ACTIVITIES
Accruals for equipment received	9,632	264
Equipment financed	$ 41,002	$ 36