Balance Sheet Accounts - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Billed receivables under long-term contracts	$ 183.1	$ 122.9
Reserve on billed trade receivables	(1.0)	(10.6)
Other trade receivables	0.3	0.2
Accounts receivable, net	$ 182.4	$ 112.5

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Balance Type:	debit
Period Type:	instant