Goodwill and Intangible Assets - Narrative Disclosures (Details) - Claims Analytics Inc. $ in Millions	1 Months Ended
Jun. 30, 2018 USD ($)
Goodwill And Intangible Assets [Line Items]
Percentage of voting interests acquired	100.00%
Customer relationships
Goodwill And Intangible Assets [Line Items]
Definite-lived intangible assets acquired during the year	$ 4

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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