Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 136,111	$ 224,410
Adjustments to reconcile net income to net cash provided by operating activities:
Allowance for credit losses	6,713	3,535
Depreciation	31,509	31,740
Amortization of cloud computing implementation costs	7,569	372
Amortization of intangible assets	668	683
Stock-based compensation	26,560	22,914
Deferred income taxes	(4,289)	(2,015)
Changes in assets and liabilities:
Accounts receivable	153,913	(50,943)
Capitalized cloud computing implementation costs	(18,846)	(11,914)
Accounts payable and accrued expenses	23,095	(15,047)
Accrued payroll and benefit cost	12,461	32,144
Income taxes payable	43,723	4,702
Other assets and liabilities, net	6,755	7,246
Net cash flows provided by operating activities	425,942	247,827
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(22,264)	(28,625)
Payments for employee deferred compensation plans	(49,098)	(40,336)
Redemptions from employee deferred compensation plans	28,347	21,232
Net cash flows used in investing activities	(43,015)	(47,729)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of notes payable	(107)	(98)
Repurchases of common stock	(69,977)	(133,617)
Dividends paid	(78,916)	(73,960)
Net cash flows used in financing activities	(149,000)	(207,675)
Effect of exchange rate fluctuations	(2,920)	438
Change in cash and cash equivalents	231,007	(7,139)
Cash and cash equivalents at beginning of period	270,478	276,579
Cash and cash equivalents at end of period	501,485	269,440
Non-cash items:
Stock repurchases awaiting settlement	$ 0	$ 5,691