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	$ 3,963	$ 2,738
Adjustments to reconcile net income to net cash from operating activities:
Provision for doubtful accounts	128	155
Reserve for product returns	554	473
Amortization for patents and tooling	247	134
Amortization and depreciation	2,864	1,591
Amortization of debt issuance costs	23	26
Deferred income taxes	(1,123)	113
Change in fair value of contingent liability	0	(60)
Undistributed (gains) / losses from equity investees	(5)	12
Stock-based compensation	1,313	852
Changes in operating assets and liabilities (net of business acquisitions):
Accounts receivable	1,580	(2,812)
Inventory	3,553	(1,109)
Other assets	668	199
Accounts payable, accrued expenses and other current liabilities	483	3,661
Deferred revenue	(213)	237
Other liabilities	(1,066)	1,076
Cash flows from operating activities	12,969	7,286
Cash flows used in investing activities:
Business acquisitions, net of cash acquired	(154,289)	0
Additions to property and equipment	(2,637)	(2,538)
Issuances of notes receivable	(1,000)	(73)
Repayments of notes receivable	0	2,441
Cash flows used in investing activities	(157,926)	(170)
Cash flows from financing activities:
Proceeds from credit facility	67,000	0
Issuances of common stock from equity-based plans	473	371
Cash flows from financing activities	67,473	371
Net (decrease) / increase in cash and cash equivalents	(77,484)	7,487
Cash and cash equivalents at beginning of the period	140,634	128,358
Cash and cash equivalents at end of the period	63,150	135,845
Supplemental disclosure of noncash investing and financing activities:
Cash not yet paid for business acquisitions	0	417
Assumed options from business acquisition	1,375	0
Contingent liability from business acquisition	0	170
Cash not yet paid for capital expenditures	$ 374	$ 1,271