Summary Of Significant Accounting Policies (Narrative) (Details)		12 Months Ended
	Mar. 08, 2019 USD ($)	Dec. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jan. 01, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Foreign currency translation gain (loss)		$ 1,800,000	$ (1,200,000)	$ (2,600,000)
Advertising expense		1,100,000	1,700,000	732,000
Allowance for doubtful accounts		973,000	966,000
Write-down to inventory		1,700,000	601,000	212,000
Write-downs to deferred preservation costs		1,700,000	787,000	$ 437,000
Write-down to non-conforming tissues		826,000
Net present value of operating lease liability		19,797,000	23,405,000
Operating lease right-of-use assets, net		$ 18,571,000	$ 21,994,000
Weighted average discount rate	5.83%	5.20%	5.40%		5.50%
Weighted average remaining lease term		5 years 1 month 6 days	5 years 6 months		6 years
Deferred rent obligations		$ 2,400,000
Option to extend		29
Number of leases with termination option | item		1
Operating lease, termination option, notice period requirement		2 years
Increase in net present value of right-of-use asset	$ 3,700,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Advertising expense amortization period		6 months
Estimated useful lives		3 years
Lease terms		1 year
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Advertising expense amortization period		1 year
Estimated useful lives		10 years
Lease terms		11 years
ESPP Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP, percentage of market price for eligible employees		85.00%
RSAs, PSAs, RSUs, PSUs And Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		1 year
RSAs, PSAs, RSUs, PSUs And Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period within grant date stock options granted typically expire		7 years
ASU 2016-09 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net present value of operating lease liability					$ 22,700,000
Operating lease right-of-use assets, net					$ 22,700,000