CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 423,500	$ 636,899
Marketable securities, short-term	297,422	98,460
Accounts receivable, net of allowance for doubtful accounts of $4,998 and $2,378, respectively	520,094	439,009
Inventories	81,124	55,641
Prepaid expenses and other current assets	135,234	72,470
Total current assets	1,457,374	1,302,479
Marketable securities, long-term	44,969	9,112
Property, plant and equipment, net	599,611	521,329
Operating lease right-of-use assets	57,269	0
Equity method investments	0	45,913
Goodwill and intangible assets, net	78,852	81,949
Deferred tax assets	59,050	64,689
Other assets	48,892	26,987
Total assets	2,346,017	2,052,458
Current liabilities:
Accounts payable	61,950	64,256
Accrued liabilities	245,634	234,679
Deferred revenues	481,462	393,138
Total current liabilities	789,046	692,073
Income tax payable	98,182	78,008
Operating lease liabilities	59,140	0
Other long-term liabilities	25,967	29,486
Total liabilities	972,335	799,567
Commitments and contingencies (Notes 9 and 10)
Stockholders’ equity:
Preferred stock, $0.0001 par value (5,000 shares authorized; none issued)	0	0
Common stock, $0.0001 par value (200,000 shares authorized; 79,865 and 79,778 issued and outstanding, respectively)	8	8
Additional paid-in capital	874,275	877,514
Accumulated other comprehensive income (loss), net	(1,876)	(2,774)
Retained earnings	501,275	378,143
Total stockholders’ equity	1,373,682	1,252,891
Total liabilities and stockholders’ equity	$ 2,346,017	$ 2,052,458