CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
REVENUES
Customer services	$ 638,204	$ 553,329	$ 1,173,758	$ 1,041,230
COSTS AND EXPENSES
Cost of services provided	297,862	255,622	559,414	506,774
Depreciation and amortization	23,306	21,925	46,902	43,522
Sales, general and administrative	183,482	171,253	345,690	329,115
Gain on sale of assets, net	(891)	(451)	(33,151)	(726)
Interest expense, net	506	1,460	1,112	3,625
INCOME BEFORE INCOME TAXES	133,939	103,520	253,791	158,920
PROVISION FOR INCOME TAXES	35,085	28,162	62,294	40,294
NET INCOME	$ 98,854	$ 75,358	$ 191,497	$ 118,626
NET INCOME PER SHARE - BASIC AND DILUTED	$ 0.20	$ 0.15	$ 0.39	$ 0.24
DIVIDENDS PAID PER SHARE	$ 0.08	$ 0.05	$ 0.16	$ 0.13
Weighted average shares outstanding - basic and diluted	491,999,000	491,645,000	491,950,000	491,585,000