Consolidated Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 20,410	$ 31,833
Accounts receivable, trade, less allowance of $8,797 and $10,298, respectively	235,763	251,023
Other receivables	17,769	17,241
Inventories and supplies	15,670	16,415
Prepaid taxes, licenses and permits	11,953	15,657
Income taxes receivable	14,709	20,052
Other current assets	27,504	27,281
Total current assets	343,778	379,502
Property and equipment	1,951,258	1,908,600
Less – accumulated depreciation	750,068	754,130
Property and equipment, net	1,201,190	1,154,470
Other non-current assets	64,597	51,675
Total assets	1,609,565	1,585,647
Current liabilities:
Accounts payable	78,069	70,643
Self insurance reserve, current	65,387	64,106
Accrued payroll	25,292	25,233
Other current liabilities	21,892	23,720
Total current liabilities	190,640	183,702
Long-term debt, net of current portion	75,000	75,000
Other long-term liabilities	20,823	19,832
Self insurance reserve, noncurrent	120,945	125,195
Deferred income taxes	$ 252,187	$ 246,264
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value, 200,000,000 shares authorized; 80,533,536 shares issued; 72,043,671 and 71,998,750 shares outstanding, respectively	$ 805	$ 805
Paid-in capital	101,217	102,734
Retained earnings	1,038,736	1,022,966
Accumulated other comprehensive loss	(13,742)	(13,063)
Treasury stock, at cost; 8,489,865 and 8,534,786 shares, respectively	(177,046)	(177,788)
Total stockholders’ equity	949,970	935,654
Total liabilities and stockholders’ equity	$ 1,609,565	$ 1,585,647