Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 08, 2021	Jun. 30, 2020
Entity Information [Line Items]
Entity Registrant Name	PROTECTIVE INSURANCE CORP
Entity Central Index Key	0000009346
Current Fiscal Year End Date	--12-31
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	0-5534
Entity Incorporation, State or Country Code	IN
Entity Tax Identification Number	35-0160330
Entity Address, Address Line One	111 Congressional Boulevard
Entity Address, City or Town	Carmel
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46032
City Area Code	317
Local Phone Number	636-9800
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 149,681,000
Entity Common Stock, Shares Outstanding		14,156,151
Common Class A (voting) [Member]
Entity Information [Line Items]
Title of 12(b) Security	Class A Common Stock, No Par Value
Trading Symbol	PTVCA
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		2,603,350
Common Class B (non-voting) [Member]
Entity Information [Line Items]
Title of 12(b) Security	Class B Common Stock, No Par Value
Trading Symbol	PTVCB
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		11,552,801