Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating Activities:
Net earnings	$ 382,226	$ 316,974	$ 731,706	$ 604,924
Adjustments to reconcile net earnings to net cash from operating activities:
Provisions for losses on accounts receivable	4,763	1,090	4,347	2,289
Deferred income tax (benefit) expense	(8,622)	1,850	(11,858)	10,001
Stock compensation expense	25,518	30,909	37,121	42,094
Depreciation and amortization	14,254	12,675	27,229	25,662
Other, net	(1,746)	346	(1,291)	897
Changes in operating assets and liabilities:
Decrease (increase) in accounts receivable	378,291	(410,783)	245,943	(663,697)
(Decrease) increase in accounts payable and accrued expenses	(133,171)	99,944	7,020	333,182
Decrease (increase) in deferred contract costs	37,138	(150,382)	211,068	(221,640)
(Decrease) increase in contract liabilities	(45,574)	174,504	(238,931)	254,094
Decrease in income taxes payable, net	(93,430)	(47,994)	(47,171)	(1,356)
(Increase) decrease in other, net	(1,001)	1,164	7,409	(324)
Net cash from operating activities	558,646	30,297	972,592	386,126
Investing Activities:
Purchase of property and equipment	(38,158)	(6,539)	(52,570)	(14,930)
Other, net	(134)	138	(55)	104
Net cash from investing activities	(38,292)	(6,401)	(52,625)	(14,826)
Financing Activities:
Proceeds from borrowing on lines of credit, net	28,571	174	48,061	89
Proceeds from issuance of common stock	5,682	22,711	11,433	42,468
Repurchases of common stock	(549,065)	(62,472)	(549,065)	(148,469)
Dividends paid	(109,828)	(98,387)	(109,828)	(98,387)
Payments for taxes related to net share settlement of equity awards	(11,851)	(13,893)	(19,333)	(15,168)
Net cash from financing activities	(636,491)	(151,867)	(618,732)	(219,467)
Effect of exchange rate changes on cash and cash equivalents	(46,518)	8,699	(52,956)	(5,503)
Change in cash and cash equivalents	(162,655)	(119,272)	248,279	146,330
Cash and cash equivalents at beginning of period	2,139,626	1,793,393	1,728,692	1,527,791
Cash and cash equivalents at end of period	1,976,971	1,674,121	1,976,971	1,674,121
Taxes Paid:
Income taxes	$ 236,791	$ 143,959	$ 314,751	$ 190,536