CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ (16,832)	$ 9,523
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	76,564	73,264
Deferred income taxes	(704)	1,266
Share-based compensation	50,993	49,127
Gain on investments, net	(2,632)	(1,190)
Changes in assets and liabilities, net of effect of acquisitions:
Accounts receivable	8,420	(32,698)
Inventories	2,349	12,624
Prepaid expenses and other assets	(5,802)	5,343
Accounts payable	(14,876)	4,876
Accrued liabilities and other liabilities	(3,104)	15,132
Net cash provided by operating activities	94,376	137,267
Cash flows from investing activities:
Purchase of severance-related insurance policies	(983)	(865)
Purchase of short-term investments	(139,861)	(218,642)
Proceeds from sales of short-term investments	95,414	209,456
Proceeds from maturities of short-term investments	31,008	130,187
Purchase of property and equipment	(35,243)	(32,748)
Purchase of intangible assets	(1,836)	(6,060)
Purchase of investments in private companies	(13,500)	(1,284)
Acquisition, net of cash acquired	(872)	(693,692)
Net cash used in investing activities	(65,873)	(613,648)
Cash flows from financing activities:
Proceeds from term debt	0	280,000
Principal payments on term debt	(46,000)	(27,000)
Term debt issuance costs	0	(5,521)
Payments on capital lease and intangible asset financings	(5,969)	(491)
Proceeds from issuances of ordinary shares through employee equity incentive plans	25,102	21,649
Net cash provided by (used in) financing activities	(26,867)	268,637
Net increase (decrease) in cash and cash equivalents	1,636	(207,744)
Cash and cash equivalents at beginning of period	56,780	263,199
Cash and cash equivalents at end of period	58,416	55,455
Supplemental disclosure of non-cash investing and financing activities
Intangible assets financed with debt	12,892	6,989
Unpaid additions to property and equipment	8,042	1,778
Transfer from inventory to property and equipment	$ 1,565	$ 3,073