CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	[1]
Current assets:
Cash and cash equivalents	$ 928,517	$ 899,509
Marketable securities-available-for-sale	269,865	270,136
Accounts receivable	316,310	266,299
Inventory	5,869	6,482
Prepaid expenses and other current assets	77,523	62,428
Total current assets	1,598,084	1,504,854
Restricted cash and investments	1,000	925
Long term investments	131,330	134,356
Inventory	6,701	7,966
Property and equipment, net	267,586	259,763
Other intangible assets, net	226,132	236,901
Goodwill	155,593	155,593
Other assets, net	10,731	2,224
Total assets	2,397,157	2,302,582
Current liabilities:
Accounts payable	75,559	67,671
Accrued compensation	41,704	74,550
Interest payable	33	33
Accrued and other current liabilities	213,888	198,901
Convertible senior notes	7,554	7,393
Acquisition-related contingent consideration	29,501	26,848
Total current liabilities	368,239	375,396
Convertible senior notes	17,016	16,608
Acquisition-related contingent consideration	258,499	260,152
Other liabilities	20,480	19,797
Total liabilities	664,234	671,953
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; none issued or outstanding as of June 30, 2018 and December 31, 2017
Common stock, $0.001 par value; 400,000,000 shares authorized; 212,409,152 and 211,262,906 shares issued and outstanding as of June 30, 2018 and December 31, 2017, respectively	212	211
Additional paid-in capital	3,718,518	3,627,433
Accumulated other comprehensive loss	(9,809)	(7,010)
Accumulated deficit	(1,975,998)	(1,990,005)
Total stockholders' equity	1,732,923	1,630,629
Total liabilities and stockholders' equity	$ 2,397,157	$ 2,302,582

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