Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Operating Activities:
Net earnings	$ 175,151	$ 195,793	$ 345,551	$ 421,791
Adjustments to reconcile net earnings to net cash from operating activities:
Provisions for losses (recoveries) on accounts receivable	1,644	(167)	2,038	905
Deferred income tax benefit	(6,917)	(3,560)	(4,623)	(1,524)
Stock compensation expense	25,704	18,595	38,076	31,083
Depreciation and amortization	14,979	15,506	30,140	30,767
Other, net	1,885	2,564	3,870	3,723
Changes in operating assets and liabilities:
(Increase) decrease in accounts receivable	(286,085)	174,321	(346,627)	682,927
Increase (decrease) in accounts payable and accrued liabilities	211,692	(149,986)	295,283	(352,909)
(Increase) decrease in deferred contract costs	(122,258)	18,166	(186,320)	85,787
Increase (decrease) in contract liabilities	135,067	(23,803)	204,375	(108,250)
Decrease in income taxes payable, net	(29,854)	(93,817)	(7,168)	(93,726)
Increase in other, net	5,761	4,834	9,078	4,284
Net cash from operating activities	126,769	158,446	383,673	704,858
Investing Activities:
Purchase of property and equipment	(7,943)	(10,481)	(18,124)	(20,607)
Other, net	66	(794)	163	(219)
Net cash from investing activities	(7,877)	(11,275)	(17,961)	(20,826)
Financing Activities:
Proceeds from borrowings on lines of credit	4,082	7,054	4,126	18,549
Payments on borrowings on lines of credit	(2,823)	(5,743)	(20,109)	(32,145)
Proceeds from issuance of common stock	6,449	9,176	14,478	18,464
Repurchases of common stock	(102,300)	(687,689)	(462,824)	(901,191)
Dividends paid	(102,638)	(102,263)	(102,638)	(102,263)
Payments for taxes related to net share settlement of equity awards	(10,163)	(12,056)	(15,348)	(19,501)
Net cash from financing activities	(207,393)	(791,521)	(582,315)	(1,018,087)
Effect of exchange rate changes on cash and cash equivalents	(10,102)	(7,857)	(24,427)	(1,489)
Change in cash and cash equivalents	(98,603)	(652,207)	(241,030)	(335,544)
Cash and cash equivalents at beginning of period	1,370,456	2,350,794	1,512,883	2,034,131
Cash and cash equivalents at end of period	1,271,853	1,698,587	1,271,853	1,698,587
Taxes Paid:
Income taxes	$ 96,739	$ 173,670	$ 133,603	$ 244,456