CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net income	$ 112,672	$ 101,998
Adjustments to reconcile net income to net cash provided by operating activities:
Asset impairments	136	0
Depreciation and amortization	10,554	10,453
Amortization of intangible assets	10,990	9,544
Amortization of debt issuance expenses	366	343
Share-based compensation expense	7,752	6,730
Deferred income taxes	561	2,012
Non-cash interest expense associated with forward starting swaps	859	1,545
Changes in (net of the effect from acquisitions):
Receivables	(46,289)	(24,190)
Inventories	(7,539)	(23,717)
Other current assets	3,350	(14,267)
Trade accounts payable	20,042	14,146
Deferred revenue	11,089	25,651
Accrued expenses	(11,592)	(23,870)
Other - net	(3,627)	(1,618)
Net cash flows provided by operating activities	109,324	84,760
Cash flows from investing activities
Purchases of property, plant and equipment	(14,609)	(12,762)
Acquisition of businesses, net of cash acquired	(106,236)	(120,839)
Proceeds from disposal of fixed assets	211	41
Other - net	1,100	(160)
Net cash flows used in investing activities	(119,534)	(133,720)
Cash flows from financing activities
Borrowings under revolving credit facilities	0	150,000
Dividends paid	(38,149)	(38,736)
Proceeds from stock option exercises	3,231	2,089
Repurchases of common stock	0	(108,907)
Shares surrendered for tax withholding	(5,460)	(12,119)
Other - net	(46)	(129)
Net cash flows used in financing activities	(40,424)	(7,802)
Effect of exchange rate changes on cash and cash equivalents	(17,075)	(6,600)
Net decrease in cash	(67,709)	(63,362)
Cash and cash equivalents at beginning of year	1,025,851	632,581
Cash and cash equivalents at end of period	958,142	569,219
Cash paid for:
Interest	483	276
Income taxes	$ 18,322	$ 10,492