Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Basis of Presentation - Narrative (Details) shares in Millions, $ in Millions		12 Months Ended
	Jan. 31, 2017 USD ($)	Dec. 31, 2018 segment	Dec. 31, 2017 segment shares	Sep. 29, 2017
Equity, Class of Treasury Stock [Line Items]
Ratio				0.3066322
Period in force	3 years
Number of segments \| segment		2	2
Common Class A
Equity, Class of Treasury Stock [Line Items]
Authorized amount \| $	$ 10.0
FNF subsidiaries \| Common Class B \| Black Knight Financial Services, LLC
Equity, Class of Treasury Stock [Line Items]
Noncontrolling interest, shares owned by noncontrolling owners \| shares			83.3