CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 16,773	$ 57,552
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred revenue and recognition of unbilled receivables	(29,266)	(4,873)
Depreciation	4,422	2,398
Amortization of intangibles	10,986	10,987
Amortization of premium and discount on investments, net	(2,329)	(1,260)
Stock-based compensation to employees	6,163	5,404
Stock-based compensation to Board of Directors and Scientific Advisory Board	2,003	1,328
Earnout liability recorded for Adesis acquisition		469
Deferred income tax expense	19,312	7,408
Retirement plan expense	2,252	2,088
Decrease (increase) in assets:
Accounts receivable	16,772	(14,708)
Inventory	(19,778)	(7,123)
Other current assets	(9,058)	(799)
Other assets	(37,909)	(10)
Increase (decrease) in liabilities:
Accounts payable and accrued expenses	(13,123)	(1,916)
Other current liabilities	(25)	(821)
Deferred revenue	64,423	505
Other liabilities	18,334
Net cash provided by operating activities	49,952	56,629
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(13,420)	(9,717)
Purchases of investments	(260,711)	(255,224)
Proceeds from sale of investments	211,847	189,335
Net cash used in investing activities	(62,284)	(75,606)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	436	349
Repurchase of common stock	(477)
Proceeds from the exercise of common stock options		30
Payment of withholding taxes related to stock-based compensation to employees	(11,031)	(8,501)
Cash dividends paid	(5,659)	(2,828)
Net cash used in financing activities	(16,731)	(10,950)
DECREASE IN CASH AND CASH EQUIVALENTS	(29,063)	(29,927)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	132,840	139,365
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 103,777	$ 109,438