Restructuring Charges (Narrative) (Details) - Workforce Reduction Plan - USD ($) $ in Millions	1 Months Ended	12 Months Ended
Apr. 30, 2020	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Percentage of positions eliminated or furloughed	23.00%
Severance costs		$ 28.0

Amount of expenses for special or contractual termination benefits provided to current employees involuntarily terminated under a benefit arrangement associated exit or disposal activities pursuant to an authorized plan. Excludes expenses related to one-time termination benefits, a discontinued operation or an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

Name:	us-gaap_SeveranceCosts1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration