CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net income	$ 65,554	$ 128,644
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	149,211	135,700
Deferred income taxes	9,220	(630)
Gain on disposal of property and equipment	(30,229)	(41,138)
Non-cash equity compensation	6,291	6,085
Insurance and claims accruals, net of current portion	(5,049)	4,874
Loss (gain) on investments in equity securities, net	2	(14,289)
Loss from equity method investment	844	0
Other	(2,445)	(4,142)
Changes in certain working capital items:
Accounts receivable, net	81,221	(21,125)
Other current assets	16,255	20,728
Accounts payable	(4,493)	30,091
Other current liabilities	(4,592)	22,729
Net cash provided by operating activities	281,790	267,527
Cash flows from investing activities:
Additions to property and equipment	(361,312)	(227,334)
Proceeds from sales of property and equipment	107,121	73,911
Net cash invested in acquisition	(188)	705
Investment in equity securities	0	(20,250)
Payment to acquire equity method investment	(2,645)	0
Issuance of notes receivable	(25,000)	0
Decrease in notes receivable	1,707	3,288
Net cash used in investing activities	(280,317)	(169,680)
Cash flows from financing activities:
Repayments of short-term debt	(3,750)	(2,500)
Repayments of long-term debt	(50,000)	(100,000)
Proceeds from issuance of long-term debt	0	120,000
Change in checks issued in excess of cash balances	11,530	6,032
Dividends on common stock	(16,459)	(15,702)
Repurchases of common stock	0	(102,113)
Tax withholding related to net share settlements of restricted stock awards	(5,517)	(3,658)
Net cash used in financing activities	(64,196)	(97,941)
Effect of exchange rate fluctuations on cash	1,985	322
Net increase (decrease) in cash and cash equivalents	(60,738)	228
Cash and cash equivalents, beginning of period	107,240	54,196
Cash and cash equivalents, end of period	46,502	54,424
Supplemental disclosures of cash flow information:
Interest paid	16,643	3,236
Income taxes paid	11,438	31,096
Supplemental schedule of non-cash investing and financing activities:
Notes receivable issued upon sale of property and equipment	1,504	2,350
Change in fair value of interest rate swaps	(1,074)	4,914
Property and equipment acquired included in accounts payable	5,774	8,431
Property and equipment disposed included in other receivables	0	1,205
Dividends accrued but not yet paid at end of period	8,874	8,244
Contingent consideration associated with acquisitions	$ (800)	$ 0