CONSOLIDATED STATEMENTS OF STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
OPERATING ACTIVITIES
Net income	$ 198,205	$ 152,582
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	65,926	58,505
Provision for deferred income taxes	3,701	(6,972)
Provision for bad debts	12,820	10,216
Stock-based compensation expense	18,151	10,891
Other, net	2,052	(951)
Changes in operating assets and liabilities	39,752	19,619
Net cash provided by operating activities	340,607	243,890
INVESTING ACTIVITIES
Cash used for acquisitions of companies, net of cash acquired	(79,880)	(431,249)
Purchases of equipment and property	(17,690)	(18,701)
Proceeds from sales of franchises	430	612
Other	2,609	1,370
Net cash used in investing activities	(94,531)	(447,968)
FINANCING ACTIVITIES
Payment of contingent consideration	(24,168)	(13,572)
Repayment of term loan	(20,000)	(27,000)
Repayment on revolving commitment	(169,500)	(45,000)
Borrowings on term loan		250,000
Borrowings on revolving commitment	68,000	148,000
Cash paid for common stock purchased	(8,085)	(9,935)
Dividends paid	(91,745)	(103,093)
Net cash (used in)/provided by financing activities	(245,498)	199,400
Effect of exchange rate changes on cash	586	(6,445)
Net increase/(decrease) in cash and cash equivalents	1,164	(11,143)
Cash and cash equivalents at beginning of period	94,276	115,485
Cash and cash equivalents at end of period	95,440	104,342
Supplemental disclosure of cash flow information:
Non-cash additions to operating lease right-of-use assets	$ 67,877	$ 54,657