Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ (7,708)	$ 5,793	$ 9,435	$ 4,507	$ (1,915)	$ 13,942
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization					6,459	2,943
Non-cash operating lease cost					725	591
Goodwill impairment	0		0		18,144	0	$ (0)
Change in fair value of contingent consideration	4,196		0		(20,326)	0
Loss on disposal of fixed assets					265	721
Loss on impairment of intangible asset					1,025	281	(389)
Stock-based compensation expense					2,033	2,829
Deferred income taxes					(907)	120
Provision (recovery) for doubtful accounts					(36)	0
Provision for inventory					3,259	601
Amortization of acquisition related inventory step-up					4,123	0
Accretion of amortized cost of investments					0	(757)
Changes in operating assets and liabilities:
Accounts receivable					6,208	(2,293)
Inventories					(5,410)	(3,033)
Prepaid expenses, other current and long-term assets					(373)	356
Accounts payable					(2,462)	(906)
Operating lease liabilities					(675)	(534)
Accrued expenses, other current and long-term liabilities					(5,135)	(1,300)
Income taxes					(389)	371
Net cash provided by operating activities					4,613	13,932
Cash flows from investing activities:
Acquisition of Parcus Medical and Arthrosurface, net of cash acquired					(93,859)	0
Proceeds from maturities of investments					20,000	72,594
Purchases of investments					(20,035)	(73,896)
Purchases of property and equipment					(908)	(2,131)
Net cash used in investing activities					(94,802)	(3,433)
Cash flows from financing activities:
Repurchases of common stock					0	(30,000)
Repayments of long term debt					(351)	0
Proceeds from long term debt					50,000	0
Cash paid for tax withheld on vested restricted stock awards					(200)	(125)
Proceeds from exercises of equity awards					68	6
Net cash provided by (used in) financing activities					49,517	(30,119)
Exchange rate impact on cash					(45)	(15)
Decrease in cash and cash equivalents					(40,717)	(19,635)
Cash and cash equivalents at beginning of period		$ 157,463		$ 89,042	157,463	89,042	89,042
Cash and cash equivalents at end of period	116,746		69,407		116,746	69,407	$ 157,463
Supplemental disclosure of cash flow information:
Right-of-use assets obtained in exchange for operating lease liabilities as of January 1, 2019	$ 593		$ 497		1,137	994
Non-cash Investing Activities:
Purchases of property and equipment included in accounts payable and accrued expenses					61	211
Consideration for acquisitions included in accounts payable and accrued expenses					1,209	0
Acquisition related contingent consideration					69,076	0
Accounting Standards Update 2016-02 [Member]
Supplemental disclosure of cash flow information:
Right-of-use assets obtained in exchange for operating lease liabilities as of January 1, 2019					$ 0	$ 24,110