Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets
Cash and cash equivalents	$ 30,367	$ 86,778
Accounts receivable (less allowance for doubtful accounts of $3,434 at March 31, 2012 and $3,346 at December 31, 2011)	133,760	156,396
Inventory	6,108	7,110
Prepaid expenses	10,378	8,955
Current deferred income tax asset	7,594	9,590
Other current assets	7,507	6,688
Total current assets	195,714	275,517
Property, plant and equipment (less accumulated depreciation of $236,099 at March 31, 2012 and $231,221 at December 31, 2011)	68,954	71,583
Goodwill	565,651	565,651
Other intangible assets (less accumulated amortization of $15,945 at March 31, 2012 and $15,741 at December 31, 2011)	14,785	14,989
Other assets	5,595	4,774
Total assets	850,699	932,514
Liabilities and Stockholders' Equity
Current maturities of long-term debt	10,719	69,188
Accounts payable	39,251	46,373
Accrued payroll and related expenses	13,713	22,227
Customer advances and deferred revenue	35,837	36,731
Income taxes payable	1,844	4,594
Other current liabilities	20,295	25,956
Total current liabilities	121,659	205,069
Long-term debt	107,187	110,250
Other long-term liabilities (including deferred income taxes of $94,909 at March 31, 2012 and $92,448 at December 31, 2011)	171,912	170,840
Total liabilities	400,758	486,159
Stockholders' equity
Common stock, $1 par value per share, 250,000,000 shares authorized. 118,672,601 shares issued at March 31, 2012 and 118,487,455 shares issued at December 31, 2011	118,673	118,487
Additional paid-in capital	341,455	341,149
Retained earnings	1,277,654	1,276,266
Less treasury stock: 55,681,846 shares at cost at March 31, 2012 and 55,668,137 shares at cost at December 31, 2011	(1,244,305)	(1,244,224)
Accumulated other comprehensive loss	(43,536)	(45,323)
Total stockholders' equity	449,941	446,355
Total liabilities and stockholders' equity	$ 850,699	$ 932,514