CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net (loss) income	$ (2,514)	$ 29,744
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	46,231	19,775
Deferred income taxes	1,266	134
Share-based compensation	36,360	25,004
Gain on investments, net	(489)	(2,388)
Impairment loss on equity investment in a private company	0	3,189
Changes in assets and liabilities, net of effect of acquisition:
Accounts receivable	(16,886)	3,918
Inventories	10,598	(22,513)
Prepaid expenses and other assets	3,598	419
Accounts payable	9,679	8,755
Accrued liabilities and other liabilities	5,583	21,063
Net cash provided by operating activities	93,426	87,100
Cash flows from investing activities:
Purchase of severance-related insurance policies	(546)	(381)
Purchase of short-term investments	(153,486)	(188,161)
Proceeds from sales of short-term investments	200,457	98,742
Proceeds from maturities of short-term investments	97,388	30,717
Purchase of property and equipment	(15,755)	(20,413)
Purchase of equity investments in private companies	(107)	0
Acquisition net of cash acquired of $87.5 million	(698,501)	0
Net cash used in investing activities	(570,550)	(79,496)
Cash flows from financing activities:
Proceeds from term debt	280,000	0
Principal payments on term debt	(7,000)	0
Term debt issuance costs	(5,521)	0
Principal payments on capital lease obligations	(491)	(556)
Proceeds from exercise of share awards	10,438	9,829
Net cash provided by financing activities	277,426	9,273
Net (decrease) increase in cash and cash equivalents	(199,698)	16,877
Cash and cash equivalents at beginning of period	263,199	51,326
Cash and cash equivalents at end of period	$ 63,501	$ 68,203