CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net income	$ 214,851	$ 172,862
Adjustments to reconcile net income to net cash provided by operating activities:
Asset impairments	226	0
Depreciation and amortization	21,480	20,591
Amortization of intangible assets	24,513	20,032
Amortization of debt issuance expenses	961	976
Share-based compensation expense	13,245	13,665
Deferred income taxes	(13,982)	2,421
Non-cash interest expense associated with forward starting swaps	3,275	4,284
Termination of the U.S. pension plan	9,688	0
Changes in (net of the effect from acquisitions):
Receivables	(46,257)	34,253
Inventories	(20,936)	(9,529)
Other current assets	125	(18,421)
Trade accounts payable	22,569	(6,842)
Deferred revenue	15,502	20,346
Accrued expenses	1,217	(3,084)
Other - net	(881)	2,659
Net cash flows provided by operating activities	245,596	254,213
Cash flows from investing activities
Purchases of property, plant and equipment	(30,593)	(21,085)
Acquisition of businesses, net of cash acquired	(575,606)	(120,839)
Note receivable from collaborative partner	(4,200)	0
Proceeds from disposal of fixed assets	242	2,114
Other - net	905	(636)
Net cash flows used in investing activities	(609,252)	(140,446)
Cash flows from financing activities
Borrowings under revolving credit facilities	0	150,000
Payments under revolving credit facilities	0	(150,000)
Payment of make-whole redemption premium	(6,659)	(6,756)
Debt issuance costs	(4,611)	(4,166)
Dividends paid	(79,242)	(76,498)
Proceeds from stock option exercises	10,687	13,111
Repurchases of common stock	0	(110,342)
Shares surrendered for tax withholding	(5,534)	(12,148)
Other - net	(60)	(251)
Net cash flows provided by financing activities	63,961	2,050
Effect of exchange rate changes on cash and cash equivalents	(11,776)	(2,050)
Net (decrease) increase in cash	(311,471)	113,767
Cash and cash equivalents at beginning of year	1,025,851	632,581
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance	714,380	746,348
Cash paid for:
Interest	17,157	16,089
Income taxes	72,681	21,781
3.00% Senior Notes, due May 2030
Cash flows from financing activities
Proceeds from Issuance of Senior Notes	0	499,100
2.625% Senior Notes, due June 2031
Cash flows from financing activities
Proceeds from Issuance of Senior Notes	499,380	0
4.5% Senior Notes
Cash flows from financing activities
Payment of Senior Notes	0	(300,000)
4.20% Senior Notes, due December 2021
Cash flows from financing activities
Payment of Senior Notes	$ (350,000)	$ 0