CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 441,372	$ 389,103
Accounts receivable	321,421	312,127
Unbilled services	141,020	114,095
Inventory	48,199	74,698
Deferred income taxes	54,635	52,078
Prepaid expenses and other current assets	173,917	144,809
Total Current Assets	1,180,564	1,086,910
Property and equipment, net	872,261	849,551
Goodwill	109,820	127,779
Other assets	48,637	43,768
Total Assets	2,211,282	2,108,008
Current Liabilities:
Accounts payable	38,958	36,393
Accrued payroll and benefits	118,928	142,229
Accrued expenses and other current liabilities	141,344	119,308
Unearned revenue	234,152	202,210
Short-term debt	340,000	30,000
Income taxes payable	6,875	6,889
Total Current Liabilities	880,257	537,029
Deferred income taxes	21,299	42,295
Other liabilities	67,016	70,889
Total Liabilities	968,572	650,213
Commitments and Contingent Liabilities
Stockholders' Equity:
Preferred Stock - Par value $1.00 per share; 10,000,000 shares authorized; no shares issued and outstanding at September 30, 2012 and December 31, 2011	0	0
Common Stock - Par value $0.01 per share; 140,000,000 shares authorized;78,807,030 and 78,127,480 shares issued and outstanding, including those held in treasury, at September 30, 2012 and December 31, 2011, respectively	788	781
Paid-in capital	725,727	689,584
Retained earnings	1,566,729	1,505,894
Accumulated other comprehensive income	15,004	4,622
Treasury stock at cost (24,098,057 and 17,284,287 shares at September 30, 2012 and December 31, 2011, respectively)	(1,065,538)	(743,086)
Total Stockholders' Equity	1,242,710	1,457,795
Total Liabilities and Stockholders' Equity	$ 2,211,282	$ 2,108,008