CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	[1]
Current assets:
Cash and cash equivalents	$ 894,427	$ 899,509
Marketable securities-available-for-sale	276,632	270,136
Accounts receivable	220,190	266,299
Inventory	4,632	6,482
Prepaid expenses and other current assets	73,674	62,428
Total current assets	1,469,555	1,504,854
Restricted cash and investments	947	925
Long term investments	165,972	134,356
Inventory	7,937	7,966
Property and equipment, net	264,610	259,763
Other intangible assets, net	231,517	236,901
Goodwill	155,593	155,593
Other assets, net	9,881	2,224
Total assets	2,306,012	2,302,582
Current liabilities:
Accounts payable	74,115	67,671
Accrued compensation	51,349	74,550
Interest payable	100	33
Accrued and other current liabilities	219,873	198,901
Convertible senior notes	7,460	7,393
Acquisition-related contingent consideration	28,175	26,848
Total current liabilities	381,072	375,396
Convertible senior notes	16,811	16,608
Acquisition-related contingent consideration	258,825	260,152
Other liabilities	21,260	19,797
Total liabilities	677,968	671,953
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; none issued or outstanding as of March 31, 2018 and December 31, 2017
Common stock, $0.001 par value; 400,000,000 shares authorized; 211,888,186 and 211,262,906 shares issued and outstanding as of March 31, 2018 and December 31, 2017, respectively	212	211
Additional paid-in capital	3,666,346	3,627,433
Accumulated other comprehensive loss	(10,122)	(7,010)
Accumulated deficit	(2,028,392)	(1,990,005)
Total stockholders' equity	1,628,044	1,630,629
Total liabilities and stockholders' equity	$ 2,306,012	$ 2,302,582

[1] The condensed consolidated balance sheet at December 31, 2017 has been derived from the audited financial statements at that date.