Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 870,486	$ 1,412,517
Short-term investments	15,415	28,271
Accounts receivable, net of allowance for doubtful accounts of $16,378 and $18,228	662,401	576,313
Other current assets	258,685	232,027
Total current assets	1,806,987	2,249,128
Long-term investments	0	9,243
Property, plant and equipment, net	10,682,826	9,394,602
Goodwill	4,852,549	4,411,762
Intangible assets, net	2,383,377	2,384,972
Other assets	562,332	241,750
Total assets	20,288,071	18,691,457
Current liabilities:
Accounts payable and accrued expenses	739,117	719,257
Accrued property, plant and equipment	276,314	220,367
Current portion of capital lease and other financing obligations	98,219	78,705
Current portion of mortgage and loans payable	73,288	64,491
Current portion of senior notes	150,557	0
Other current liabilities	123,824	159,914
Total current liabilities	1,461,319	1,242,734
Capital lease and other financing obligations, less current portion	1,386,260	1,620,256
Mortgage and loans payable, less current portion	1,327,477	1,393,118
Senior notes, less current portion	8,318,782	6,923,849
Other liabilities	634,060	661,710
Total liabilities	13,127,898	11,841,667
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock, $0.001 par value per share: 300,000,000 shares authorized; 80,390,472 and 79,038,062 shares outstanding	81	79
Additional paid-in capital	10,592,960	10,121,323
Treasury stock, at cost; 397,120 and 402,342 shares	(145,216)	(146,320)
Accumulated dividends	(3,145,430)	(2,592,792)
Accumulated other comprehensive loss	(922,148)	(785,189)
Retained earnings	779,926	252,689
Total stockholders' equity	7,160,173	6,849,790
Total liabilities and stockholders' equity	$ 20,288,071	$ 18,691,457