CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 69,420	$ 40,546
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred taxes	7,789	(6,113)
Depreciation and amortization	7,867	4,792
Stock-based compensation	14,812	12,524
Net tax benefits from stock-based awards	0	7,220
Excess tax benefit from share-based payment arrangements	0	(8,082)
Equity in losses of investee	1,121	0
Other non-cash operating activities	2,079	3,754
Changes in assets and liabilities, net of effects of acquisitions:
Accounts receivable	(24,525)	(20,839)
Inventories	(7,923)	(3,155)
Prepaid expenses and other assets	(527)	(618)
Accounts payable	5,522	447
Accrued and other long-term liabilities	(39,702)	(14,544)
Deferred revenues	11,688	14,748
Net cash provided by operating activities	47,621	30,680
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisitions, net of cash acquired	(8,953)	0
Purchase of property, plant and equipment	(59,569)	(20,207)
Purchase of marketable securities	(169,777)	(143,926)
Proceeds from maturities of marketable securities	87,003	128,524
Proceeds from sales of marketable securities	11,684	293
Loan advance to privately held companies	(8,000)	0
Other investing activities	2,314	0
Net cash used in investing activities	(145,298)	(35,316)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	7,288	5,384
Common stock repurchases	(3,793)	0
Excess tax benefit from share-based payment arrangements	0	8,082
Employees’ taxes paid upon the vesting of restricted stock units	(36,496)	(22,572)
Net cash used in financing activities	(33,001)	(9,106)
Effect of foreign exchange rate changes on cash and cash equivalents	2,430	446
Net decrease in cash and cash equivalents	(128,248)	(13,296)
Cash and cash equivalents, beginning of the period	389,275	167,714
Cash and cash equivalents, end of the period	261,027	154,418
SUPPLEMENTAL CASH FLOW INFORMATION:
Accounts payable or accrued liabilities related to property, plant and equipment	$ 7,662	$ 10,842