Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 75,661	$ 57,063
Accounts receivable, net of allowance for doubtful accounts of $41,786 and $38,916, respectively	295,756	263,327
Other current assets	92,407	107,537
Total current assets	463,824	427,927
Property and equipment, net	2,966,215	2,703,695
Goodwill	2,730,362	2,681,188
Intangible assets, net	86,951	83,310
Deferred tax assets - noncurrent	3,689	3,780
Derivative instruments	26,176	73,509
Other assets	65,369	51,317
Total assets	6,342,586	6,024,726
Current liabilities:
Current portion of long-term debt	34,805	34,805
Accounts payable	95,105	80,034
Accrued salaries and benefits	99,893	105,068
Other accrued liabilities	111,403	122,958
Total current liabilities	341,206	342,865
Long-term debt	3,234,146	3,253,004
Deferred tax liabilities - noncurrent	81,672	78,520
Other liabilities	179,329	164,859
Total liabilities	3,836,353	3,839,248
Redeemable noncontrolling interests	18,648	17,754
Equity:
Preferred stock, $0.01 par value; 10,000,000 shares authorized, no shares issued
Common stock, $0.01 par value; 180,000,000 shares authorized; 87,045,124 and 86,688,199 issued and outstanding as of September 30, 2017 and December 31, 2016, respectively	870	867
Additional paid-in capital	2,512,951	2,496,288
Accumulated other comprehensive loss	(385,180)	(549,570)
Retained earnings	358,944	220,139
Total equity	2,487,585	2,167,724
Total liabilities and equity	$ 6,342,586	$ 6,024,726