Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 83,849	$ 104,628
Short term investments	250,549	215,798
Accounts receivable, net of allowances for doubtful accounts of $1,727 and $2,407 at March 31, 2012 and December 31, 2011,respectively	96,544	88,573
Revenue earned in excess of billings	15,480	5,131
Deferred income taxes and other current assets	54,662	46,353
Total current assets	501,084	460,483
Property and equipment	189,824	179,576
Less accumulated depreciation and amortization	80,154	73,574
Property and equipment, net	109,670	106,002
Goodwill	906	906
Non current Term Deposits with Banks	136	130
Deferred income taxes and other non current assets	31,780	29,727
TOTAL ASSETS	643,576	597,248
LIABILITIES AND SHAREHOLDERS' EQUITY
Accounts payable	16,554	12,299
Accrued payroll and related costs	36,658	45,949
Income taxes payable	5,711	3,080
Accrued liabilities	16,780	20,309
Deferred revenue	5,823	9,692
Dividends payable	2,734	2,733
Total current liabilities	84,260	94,062
Other non current liabilities	10,946	9,997
TOTAL LIABILITIES	95,206	104,059
SHAREHOLDERS' EQUITY
Total shareholders' equity	548,370	493,189
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 643,576	$ 597,248