Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 21, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Entity Registrant Name	Black Knight, Inc.
Entity Central Index Key	0001627014
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		150,011,919
Entity Public Float			$ 7,534,921,486
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes