CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 298,476	$ 159,784
Accounts receivable trade, net	794,785	701,512
Other receivables	2,933	3,022
Prepaid taxes	4,357	2,191
Prepaid expenses and other current assets	18,115	27,779
TOTAL CURRENT ASSETS	1,118,666	894,288
Restricted investments	19,056	24,256
Property and equipment, net	712,571	681,451
Right-of-use assets - operating leases	45,997	44,036
Right-of-use assets - financing leases	2,230	1,252
Other intangibles, net	183,883	196,672
Goodwill	577,340	576,913
Other assets	19,502	18,426
TOTAL ASSETS	2,679,245	2,437,294
CURRENT LIABILITIES:
Accounts payable trade	423,608	424,923
Accounts payable other	17,192	12,493
Accrued payroll	54,903	56,938
Accrued other	109,918	82,827
Lease liability - operating leases	12,214	11,364
Lease liability - financing leases	2,036	1,251
Current portion of long-term debt	98,774	97,273
TOTAL CURRENT LIABILITIES	718,645	687,069
Long-term debt	188,058	177,479
Non-current liabilities	43,077	41,572
Lease liability - operating leases	36,409	34,916
Lease liability - financing leases	173	0
Deferred taxes	157,694	155,944
STOCKHOLDERS' EQUITY:
Preferred stock:$.01 par value; 2,000,000 shares authorized; no shares issued or outstanding in 2022 and 2021	0	0
Additional paid-in capital	195,603	189,256
Purchase price in excess of predecessor basis, net of tax benefit of $10,306	(15,458)	(15,458)
Retained earnings	1,614,983	1,424,634
Accumulated other comprehensive loss	(203)	(207)
Treasury stock; at cost, 7,244,215 shares in 2022 and 7,317,058 shares in 2021	(260,155)	(258,330)
TOTAL STOCKHOLDERS' EQUITY	1,535,189	1,340,314
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	2,679,245	2,437,294
Class A Common Stock [Member]
STOCKHOLDERS' EQUITY:
Common stock	412	412
Class B Common Stock [Member]
STOCKHOLDERS' EQUITY:
Common stock	$ 7	$ 7