Sale of Puerto Rico Subsidiary (Details) - Puerto Rican Radiopharmacy Servicing Subsidiary - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Jan. 29, 2021
Non-Current Liabilities:
Pre-tax book gain on disposal	$ 15,300
Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal group consideration		$ 18,000
Disposal group holdback amount		1,800
Current assets
Cash and cash equivalents		540
Accounts receivable, net		1,959
Inventory		530
Other current assets		65
Total current assets		3,094
Non-Current Assets:
Property, plant & equipment, net		780
Intangibles, net		96
Other long-term assets		774
Total assets held for sale		4,744
Current liabilities
Accounts payable		185
Accrued expense and other liabilities		369
Total current liabilities		554
Non-Current Liabilities:
Asset retirement obligations		306
Other long-term liabilities		588
Total liabilities held for sale		$ 1,448