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	$ 33,713	$ 30,826
Adjustments to reconcile net income to net cash and cash equivalents provided by operating activities:
Amortization of convertible note discount and issuance costs	0	2,154
Amortization of intangibles	1,516	1,785
Depreciation	2,925	2,768
Foreign currency exchange loss	533	852
Change in fair value of contingent consideration	132	117
Share-based compensation	4,413	3,646
Gain on disposal of property, plant and equipment	0	(946)
Provision for doubtful accounts and inventory valuation	3,019	2,671
Patent litigation income	(13,000)	0
Changes in operating assets and liabilities	9,536	(12,347)
Net cash and cash equivalents provided by operating activities	42,787	31,526
Cash flows from investing activities:
Purchases of marketable securities	(103,224)	(110,283)
Proceeds from sales of marketable securities	99,931	141,936
Purchases of property, plant and equipment	(7,447)	(2,527)
Proceeds from sales of property, plant and equipment	0	1,165
Net cash and cash equivalents provided by (used in) investing activities	(10,740)	30,291
Cash flows from financing activities:
Redemption of stock warrants	(1,025)	0
Payments on redemption of convertible senior notes	0	(60,000)
Purchases of common stock	0	(8,044)
Tax payments related to shares withheld for share-based compensation plans	(1,331)	(1,573)
Payment of contingent consideration for acquired business	(358)	(94)
Issuance of shares through share-based compensation plans	289	354
Net cash and cash equivalents used in financing activities	(2,425)	(69,357)
Effect of exchange rate changes on cash and cash equivalents	545	1,532
Net increase (decrease) in cash and cash equivalents	30,167	(6,008)
Cash and cash equivalents at beginning of period	37,859	44,554
Cash and cash equivalents at end of period	68,026	38,546
Supplemental disclosure of cash flow information:
Income taxes paid	6,917	6,479
Interest paid	0	2,250
Litigation settlement received	$ 0	$ 14,643