Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities:
Net earnings	$ 349,480	$ 287,950
Adjustments to reconcile net earnings to net cash from operating activities:
(Recoveries) provisions for losses on accounts receivable	(416)	1,199
Deferred income tax (benefit) expense	(3,236)	8,151
Stock compensation expense	11,603	11,185
Depreciation and amortization	12,975	12,987
Other, net	455	551
Changes in operating assets and liabilities:
Increase in accounts receivable	(132,348)	(252,914)
Increase in accounts payable and accrued liabilities	140,191	233,238
Decrease (increase) in deferred contract costs	173,930	(71,258)
(Decrease) increase in contract liabilities	(193,357)	79,590
Increase in income taxes payable, net	46,259	46,638
Decrease (increase) in other, net	8,410	(1,488)
Net cash from operating activities	413,946	355,829
Investing Activities:
Purchase of property and equipment	(14,412)	(8,391)
Other, net	79	(34)
Net cash from investing activities	(14,333)	(8,425)
Financing Activities:
Proceeds from borrowing on lines of credit, net	19,490	(85)
Proceeds from issuance of common stock	5,751	19,757
Repurchases of common stock	0	(85,997)
Payments for taxes related to net share settlement of equity awards	(7,482)	(1,275)
Net cash from financing activities	17,759	(67,600)
Effect of exchange rate changes on cash and cash equivalents	(6,438)	(14,202)
Change in cash and cash equivalents	410,934	265,602
Cash and cash equivalents at beginning of period	1,728,692	1,527,791
Cash and cash equivalents at end of period	2,139,626	1,793,393
Taxes Paid:
Income taxes	$ 77,960	$ 46,607