Debt (Schedule of Principal Amount of Outstanding Long-Term Debt Obligations) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	May 29, 2020
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 132,763	$ 132,763	$ 129,800
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 77,226	$ 77,439	$ 78,100

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant