Revenue and Receivables from Contracts with Customers - Schedule of Allowance for Credit Losses (Narrative) (Details) - Accounting Standards Update 2016-13 - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2020
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, increase	$ 0.2
Cumulative Effect, Period of Adoption, Adjustment
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for credit losses, increase		$ 0.2

Amount of increase (decrease) in allowance for credit loss on financing receivable.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration