Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-36841
Entity Registrant Name	INOVALON HOLDINGS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-1830316
Entity Address, Address Line One	4321 Collington Road,
Entity Address, City or Town	Bowie,
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20716
City Area Code	301
Local Phone Number	809-4000
Title of 12(b) Security	Class A Common Stock, $0.000005 par value per share
Security Exchange Name	NASDAQ
Trading Symbol	INOV
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 655.7
Documents Incorporated by Reference [Text Block]	The information required by Part III (Items 10, 11, 12, 13 and 14) will be incorporated by reference from the Registrant’s definitive proxy statement relating to its 2020 annual meeting of stockholders (the “2020 Proxy Statement”). The 2020 Proxy Statement will be filed with the U.S. Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Entity Central Index Key	0001619954
Document Period End Date	Dec. 31, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Class A Common
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		75,693,145
Class B Common
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		79,369,411