CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 149,863	$ 61,435
Accounts receivable trade, net	421,139	477,088
Other receivables	3,282	22,021
Prepaid taxes	1,038	616
Prepaid expenses and other current assets	11,602	27,533
TOTAL CURRENT ASSETS	586,924	588,693
Restricted investments	21,972	19,236
Property and equipment, net	651,057	681,859
Right-of-use assets - operating leases	32,165
Right-of-use assets - financing leases	7,021
Other intangibles, net	127,878	134,788
Goodwill, net	484,568	483,584
Other assets	18,534	16,738
TOTAL ASSETS	1,930,119	1,924,898
CURRENT LIABILITIES:
Accounts payable trade	233,399	272,859
Accounts payable other	11,974	10,906
Accrued payroll	41,402	55,535
Accrued other	80,271	82,900
Lease liability - operating leases	8,468
Lease liability - financing leases	3,004	2,845
Current portion of long-term debt	98,601	101,713
TOTAL CURRENT LIABILITIES	477,119	526,758
Long-term debt	199,194	229,071
Non-current liabilities	34,537	29,619
Lease liability - operating leases	25,351
Lease liability - financing leases	3,384	4,739
Deferred taxes	157,952	153,877
STOCKHOLDERS' EQUITY:
Preferred stock, $.01 par value; 2,000,000 shares authorized; no shares issued or outstanding in 2019 and 2018
Additional paid-in capital	170,619	172,220
Purchase price in excess of predecessor basis, net of tax benefit of $10,306	(15,458)	(15,458)
Retained earnings	1,125,541	1,072,456
Accumulated other comprehensive loss	(178)	(182)
Treasury stock; at cost, 7,369,052 shares in 2019 and 7,431,083 shares in 2018	(248,361)	(248,621)
TOTAL STOCKHOLDERS' EQUITY	1,032,582	980,834
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,930,119	1,924,898
Class A Common Stock [Member]
STOCKHOLDERS' EQUITY:
Common stock	412	412
Class B Common Stock [Member]
STOCKHOLDERS' EQUITY:
Common stock	$ 7	$ 7