Condensed Consolidated Statements of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 52,689	$ 53,391
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	8,087	6,870
Bad debt provisions	3	9
Realized gains on sales of short term investments	(1,521)	(539)
Deferred income taxes	(1,974)	(3,464)
Compensation expense related to restricted stock	1,224	496
Changes in assets and liabilities:
Accounts receivable and revenue earned in excess of billings	(13,803)	(28,880)
Other assets	(5,819)	(3,127)
Accrued payroll and other liabilities	2,985	9,173
Deferred revenue	(1,006)	(233)
Net cash provided by operating activities	40,865	33,696
CASH FLOWS FROM INVESTING ACTIVITIES:
Property and equipment expenditures	(31,243)	(8,893)
Purchase of mutual funds	(101,338)	(179,347)
Purchase of term deposits with banks	(55,802)	(35,846)
Proceeds from sales of mutual funds	115,080	172,610
Maturities of term deposits with banks	45,023	27,840
Net cash used in investing activities	(28,280)	(23,636)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from issuance of common stock		580
Tax benefit on stock options exercised	(2)
Dividends paid	(4,989)	(4,969)
Net cash used in financing activities	(4,991)	(4,389)
Effect of foreign currency exchange rate changes on cash	1,557	(1,493)
Change in cash and cash equivalents	9,151	4,178
Cash and cash equivalents, beginning of period	78,505	87,822
Cash and cash equivalents, end of period	87,656	92,000
Non cash investing and financing activities:
Cash dividends declared but unpaid	2,754	2,486
Cash paid for income taxes	$ 6,525	$ 7,760