CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 8,053	$ 3,448
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,213	3,960
Non-cash interest expense	1,107	1,036
Stock-based compensation expense	3,251	2,268
Deferred tax expense	892	449
Other		1
Changes in operating assets and liabilities, excluding impact of acquisitions:
Accounts receivable	(6,692)	(1,529)
Royalties and other receivables	112	127
Unbilled receivables	2,602
Inventories	(1,478)	(1,188)
Prepaid expenses and other assets	215	(1,608)
Operating lease right of use assets	784
Accounts payable	(570)	(1,550)
Accrued expenses	(1,855)	(3,839)
Increase Decrease in Operating Lease Liability	(840)
Long-term liabilities	(6)	(3)
Total cash provided by operating activities	9,788	1,572
Cash flows from investing activities:
Additions to capitalized software costs	(1,740)
Purchases of property, plant and equipment	(2,088)	(1,564)
Total cash used in investing activities	(3,828)	(1,564)
Cash flows from financing activities:
Exercise of stock options	44	344
Repayment of senior convertible notes		(11)
Total cash provided by financing activities	44	333
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3,691)	(224)
Net increase in cash, cash equivalents and restricted cash	2,313	117
Cash, cash equivalents and restricted cash, beginning of period	193,822	173,759
Cash, cash equivalents and restricted cash, end of period	196,135	173,876
Supplemental disclosure of cash flow information:
Income taxes paid	$ 1,055	937
Supplemental disclosure of non-cash investing and financing activities:
Non-cash effect of adoption of ASU 2016-16		$ 5,609