Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 347,511	$ 372,544
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	222,919	202,210
Stock-based compensation	16,362	14,331
Amortization included in interest expense	4,920	4,527
Gain on disposition of assets	(5,243)	(1,990)
Loss on extinguishment of debt	115	0
Equity in earnings of investee	(1,326)	(2,655)
Deferred tax expense	910	1,851
Provision for doubtful accounts	8,609	5,868
(Increase) decrease in:
Receivables	(33,755)	(29,510)
Prepaid expenses	(1,097)	(2,681)
Other assets	(2,237)	3,510
(Decrease) increase in:
Trade accounts payable	(1,430)	(895)
Accrued expenses	(8,049)	(12,773)
Operating lease liabilities	(25,838)	(18,881)
Other liabilities	7,049	1,649
Net cash provided by (used in) operating activities	529,420	537,105
Cash flows from investing activities:
Acquisitions	(120,324)	(287,860)
Capital expenditures	(132,152)	(116,808)
Proceeds from disposition of assets and investments	6,489	2,146
Decrease in notes receivable	62	58
Net cash (used in) provided by investing activities	(245,925)	(402,464)
Cash flows from financing activities:
Cash used for purchase of treasury stock	(5,989)	(10,506)
Net proceeds from issuance of common stock	10,401	15,301
Principal payments on long-term debt	(284)	(273)
Principal payments on financing leases	(998)	(998)
Payments on revolving credit facility	(243,000)	(575,000)
Proceeds received from revolving credit facility	333,000	400,000
Proceeds received from accounts receivable securitization program	72,000	140,000
Payments on accounts receivable securitization program	(74,900)	(115,000)
Proceeds received from senior credit facility term loans	0	350,000
Debt issuance costs	(2,951)	(1,564)
Distributions to non-controlling interest	(1,162)	(1,019)
Dividends/distributions	(382,853)	(355,783)
Net cash used in financing activities	(296,736)	(154,842)
Effect of exchange rate changes in cash and cash equivalents	17	(232)
Net decrease in cash and cash equivalents	(13,224)	(20,433)
Cash and cash equivalents at beginning of period	52,619	99,788
Cash and cash equivalents at end of period	39,395	79,355
Supplemental disclosures of cash flow information:
Cash paid for interest	125,117	84,611
Cash paid for foreign, state and federal income taxes	$ 9,093	$ 8,254