Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 01, 2019
Entity Information [Line Items]
Entity Registrant Name	Protective Insurance Corp
Entity Central Index Key	0000009346
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		14,692,214
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Class A (voting) [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		2,615,216
Class B (nonvoting) [Member]
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		12,076,998