Schedule II - Condensed Financial Information of Registrant, Statements of Comprehensive Income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 11,971	$ 3,281	$ 11,367	$ (22,156)	$ 3,771	$ (707)	$ 1,535	$ 2,748	$ 4,463	$ 7,347	$ (34,075)
Other comprehensive income (loss), net of tax [Abstract]
Unrealized net gains (losses) on fixed income securities									12,141	16,071	(6,868)
Foreign currency translation adjustments									249	645	(830)
Other comprehensive income (loss)									12,390	16,716	(7,698)
Comprehensive income (loss)									16,853	24,063	(41,773)
Protective Insurance Corporation [Member]
Condensed Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)									4,463	7,347	(34,075)
Other comprehensive income (loss), net of tax [Abstract]
Unrealized net gains (losses) on fixed income securities									12,141	16,071	(6,868)
Foreign currency translation adjustments									249	645	(830)
Other comprehensive income (loss)									12,390	16,716	(7,698)
Comprehensive income (loss)									$ 16,853	$ 24,063	$ (41,773)