Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective income tax rate		(3.00%)	(5.00%)
Federal statutory income tax rate	21.00%
Valuation allowances against deferred tax assets	$ 13,282,000	$ 7,170,000
Net deferred tax liability	26,442,000	33,266,000
Income tax expense	7,000	(492,000)	$ (76,000)
Federal net operating loss carryforwards related to the acquisitions of Cardiogenesis and Hemosphere	2,000,000.0
State net operating loss carryforwards	3,000,000.0
Foreign net operating loss carryforwards	1,800,000
Research and development tax credit carryforwards	500,000
Other tax credit	$ 110,000
Other tax credit expiration date	Dec. 31, 2027
Tax credit carryforwards expiration date	Dec. 31, 2030
Excess interest carryforward	$ 3,547,000	2,660,000
Non-current liabilities recorded related to interest and penalties on uncertain tax positions	220,000	261,000
Penalties and interest income (expense)	35,000	180,000	(27,000)
Total uncertain tax liability including interest and penalties	4,300,000	2,800,000
Uncertain tax liability recorded as reduction to deferred tax assets	300,000	300,000
Uncertain tax liability recorded to non-current liability	4,000,000.0	2,500,000
Approximate amount of uncertain tax liability to be recognized	185,000
Approximate amount that would affect tax rate	3,200,000	2,600,000	$ 3,500,000
Interest deduction limit	11,700,000	$ 15,800,000
Correction In Calculation Of Valuation Allowance And Uncertain Tax Position [Member]
Income tax expense	$ 2,100,000
State [Member]
Operating loss carryforwards expiration date	Dec. 31, 2022
Foreign Authority [Member]
Net deferred tax liability	$ 175,000
Operating loss carryforwards expiration date	Dec. 31, 2025