Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 56,400	$ 52,183
Accounts receivable, net of allowance of $997 and $782, respectively	212,634	254,188
Prepaid expenses and other current assets	19,566	21,119
Total current assets	288,600	327,490
Property and equipment, net of accumulated depreciation of $1,512,573 and $1,475,951, respectively	2,825,203	2,802,449
Goodwill	44,779	40,927
Non-current deferred tax assets	11,194	12,814
Other assets	94,674	88,718
Total assets	3,264,450	3,272,398
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	269,458	277,804
Income taxes payable	3,957	3,034
Current portion of long-term debt	12,429	10,000
Total current liabilities	285,844	290,838
Long-term debt, net	1,455,265	1,437,187
Deferred revenue	36,327	39,735
Other liabilities	52,804	53,030
Total liabilities	1,830,240	1,820,790
Commitments and contingencies
Preferred stock – $0.01 par value; 50,000 shares authorized; none issued and outstanding at March 31, 2018 and December 31, 2017, respectively	0	0
Common stock – $0.01 par value; 300,000 shares authorized; 118,544 and 118,204 shares issued and outstanding at March 31, 2018 and December 31, 2017, respectively	1,185	1,182
Additional paid-in capital	1,795,671	1,794,713
Accumulated deficit	(360,618)	(344,287)
Accumulated other comprehensive loss	(2,028)
Total stockholders' equity	1,434,210	1,451,608
Total liabilities and stockholders' equity	$ 3,264,450	$ 3,272,398