Consolidated Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 13,736	$ 31,833
Accounts receivable, trade, less allowance of $9,080 and $10,298, respectively	252,512	251,023
Other receivables	13,536	17,241
Inventories and supplies	14,446	16,415
Prepaid taxes, licenses and permits	6,949	15,657
Income taxes receivable	13,110	20,052
Other current assets	63,568	27,281
Total current assets	377,857	379,502
Property and equipment	2,011,888	1,908,600
Less – accumulated depreciation	728,503	754,130
Property and equipment, net	1,283,385	1,154,470
Other non-current assets	65,137	51,675
Total assets	1,726,379	1,585,647
Current liabilities:
Checks issued in excess of cash balances	2,665	0
Accounts payable	72,735	70,643
Insurance and claims accruals	71,056	64,106
Accrued payroll	29,608	25,233
Other current liabilities	18,249	23,720
Total current liabilities	194,313	183,702
Long-term debt, net of current portion	150,000	75,000
Other long-term liabilities	18,275	19,832
Insurance and claims accruals, net of current portion	114,125	125,195
Deferred income taxes	271,206	246,264
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value, 200,000,000 shares authorized; 80,533,536 shares issued; 72,061,210 and 71,998,750 shares outstanding, respectively	805	805
Paid-in capital	103,648	102,734
Retained earnings	1,067,315	1,022,966
Accumulated other comprehensive loss	(16,589)	(13,063)
Treasury stock, at cost; 8,472,326 and 8,534,786 shares, respectively	(176,719)	(177,788)
Total stockholders’ equity	978,460	935,654
Total liabilities and stockholders’ equity	$ 1,726,379	$ 1,585,647