Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Operating Activities:
Net earnings (losses)	$ 811,633	$ 751,779	$ 1,360,605
Adjustments to reconcile net earnings to net cash from operating activities:
Provisions for losses on accounts receivable	3,447	3,943	11,050
Deferred income tax benefit	(5,138)	(22,916)	(33,240)
Stock compensation expense	64,364	58,399	64,397
Depreciation and amortization	61,090	67,760	57,338
Other, net	(3,359)	8,461	1,252
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(531,616)	573,724	1,592,341
Increase (decrease) in accounts payable and accrued expenses	259,310	(300,345)	(798,123)
(Increase) decrease in deferred contract costs	(147,685)	36,952	714,960
Increase (decrease) in contract liabilities	179,553	(40,076)	(798,356)
Increase (decrease) in income taxes payable, net	26,388	(77,298)	(55,129)
Decrease (increase) in other, net	5,374	(7,192)	12,580
Net cash from operating activities	723,361	1,053,191	2,129,675
Investing Activities:
Purchase of property and equipment	(40,466)	(39,314)	(86,824)
Other, net	(57)	(119)	(890)
Net cash from investing activities	(40,523)	(39,433)	(87,714)
Financing Activities:
Proceeds from borrowing on lines of credit	15,000	32,199	81,756
Payments on borrowing on lines of credit	(35,058)	(38,143)	(30,289)
Proceeds from issuance of common stock	69,257	84,889	80,980
Repurchases of common stock	(855,061)	(1,392,886)	(1,581,908)
Dividends paid	(204,087)	(202,029)	(213,799)
Payments for taxes related to net share settlement of equity awards	(15,348)	(19,506)	(19,335)
Distribution to noncontrolling interest	0	(1,089)	(1,945)
Net cash from financing activities	(1,025,297)	(1,536,565)	(1,684,540)
Effect of exchange rate changes on cash and cash equivalents	(22,104)	1,559	(51,982)
Change in cash and cash equivalents	(364,563)	(521,248)	305,439
Cash and cash equivalents at beginning of period	1,512,883	2,034,131	1,728,692
Cash and cash equivalents at end of period	1,148,320	1,512,883	2,034,131
Supplemental Cash Flow Information:
Cash paid for income taxes	$ 257,170	$ 356,380	$ 566,533