Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (155,900)	$ (133,964)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	30,503	26,581
Stock-based compensation	64,239	49,875
Non-cash interest expense related to convertible senior notes	8,780	0
Deferred income taxes	(11,053)	82
Other	938	509
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	43,144	32,736
Inventories	2,325	(2,554)
Prepaid expenses and other assets	(2,152)	127
Accounts payable	(3,391)	(4,219)
Accrued liabilities	902	2,068
Accrued transaction costs of acquiree	(7,727)	0
Accrued compensation	(8,989)	(2,675)
Deferred revenue	17,997	26,221
Other long-term liabilities	(2,132)	1,997
Net cash used in operating activities	(22,516)	(3,216)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment and demonstration units	(14,257)	(12,669)
Purchases of short-term investments	(88,805)	(39,857)
Proceeds from maturities of short-term investments	111,319	34,655
Business acquisitions, net of cash acquired	(204,926)	0
Lease deposits	(678)	(370)
Net cash used in investing activities	(197,347)	(18,241)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of debt of acquired business	(8,842)	0
Payment of shares withheld for taxes	(1,124)	0
Proceeds from exercise of equity awards	2,840	11,870
Net cash (used in) provided by financing activities	(7,126)	11,870
Net change in cash and cash equivalents	(226,989)	(9,587)
Cash and cash equivalents, beginning of period	402,102	146,363
Cash and cash equivalents, end of period	175,113	136,776
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for income taxes	1,888	536
Cash paid for interest	22	0
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Vesting of early exercised stock options	496	604
Common stock issued in connection with acquisitions	39,300	0
Contingent earn-out in connection with acquisitions	35,588	0
Purchases of property and equipment and demonstration units in accounts payable and accrued liabilities	$ 5,779	$ 5,382