CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ 9,815	$ 8,053
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,390	4,213
Non-cash interest expense	2,691	1,107
Stock-based compensation expense	4,165	3,251
Deferred tax expense		892
Other	140
Changes in operating assets and liabilities, excluding impact of acquisitions:
Accounts receivable	(2,399)	(6,692)
Royalties and other receivables	148	112
Unbilled receivables		2,602
Inventories	(7,191)	(1,478)
Prepaid expenses and other assets	36	215
Operating lease right of use assets	919	784
Accounts payable	(709)	(570)
Accrued expenses	(4,989)	(1,855)
Operating lease liability	334	(840)
Long-term liabilities	180	(6)
Total cash provided by operating activities	9,530	9,788
Cash flows from investing activities:
Additions to capitalized software costs	(911)	(1,740)
Purchases of property, plant and equipment	(4,126)	(2,088)
Total cash used in investing activities	(5,037)	(3,828)
Cash flows from financing activities:
Exercise of stock options	1,599	44
Payment of tax withholding obligation on vesting of restricted stock	(10)
Total cash provided by financing activities	1,589	44
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(4,923)	(3,691)
Net increase in cash, cash equivalents and restricted cash	1,159	2,313
Cash, cash equivalents and restricted cash, beginning of period	537,407	193,822
Cash, cash equivalents and restricted cash, end of period	538,566	196,135
Supplemental disclosure of cash flow information:
Income taxes paid	1,756	$ 1,055
Interest paid	527
Supplemental disclosure of non-cash investing and financing activities:
Assets acquired under operating leases	$ 17