CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
OPERATING ACTIVITIES
Net income	$ 180,695	$ 145,389
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	50,149	41,630
Provision for deferred income taxes	4,604	9,386
Provision for bad debts	9,509	7,222
Stock - based compensation expense	10,030	9,406
Other, net	(1,920)	(728)
Changes in operating assets and liabilities	(39,793)	(22,918)
Net cash provided by operating activities	213,274	189,387
INVESTING ACTIVITIES
Cash used for acquisitions of companies, net of cash acquired	(71,785)	(127,881)
Purchases of equipment and property	(19,645)	(17,217)
Proceeds from sales of franchises	343	437
Other	1,002	67
Net cash used in investing activities	(90,085)	(144,594)
FINANCING ACTIVITIES
Cash paid for common stock purchased	(9,533)	(8,193)
Dividends paid	(91,677)	(75,182)
Net cash used in financing activities	(101,210)	(83,375)
Effect of exchange rate changes on cash	(10,377)	9,194
Net increase/(decrease) in cash and cash equivalents	11,602	(29,388)
Cash and cash equivalents at beginning of period	107,050	142,785
Cash and cash equivalents at end of period	$ 118,652	$ 113,397