Consolidated Statements of Income - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Net premiums earned	$ 181,764,580	$ 169,156,147
Investment income, net of investment expenses	6,378,369	5,755,399
Net realized investment (losses) gains (includes ($918,339) and $2,548,975 accumulated other comprehensive income reclassifications)	(918,339)	2,548,975
Lease income	123,593	141,850
Installment payment fees	1,347,961	1,135,642
Equity in earnings of Donegal Financial Services Corporation	632,114	232,950
Total revenues	189,328,278	178,970,963
Expenses:
Net losses and loss expenses	156,583,268	114,433,458
Amortization of deferred policy acquisition costs	29,665,000	27,683,000
Other underwriting expenses	29,322,638	28,489,281
Policyholder dividends	1,302,183	834,265
Interest	464,148	363,675
Other expenses	526,212	442,455
Total expenses	217,863,449	172,246,134
(Loss) income before income tax (benefit) expense	(28,535,171)	6,724,829
Income tax (benefit) expense (includes ($192,851) and $892,141 income tax (benefit) expense from reclassification items)	(10,357,093)	1,620,011
Net (loss) income	$ (18,178,078)	$ 5,104,818
Class A Common Stock [Member]
(Loss) earnings per common share:
Common stock-basic	$ (0.66)	$ 0.19
Common stock-diluted	(0.66)	0.18
Class B Common Stock [Member]
(Loss) earnings per common share:
Common stock-basic	(0.60)	0.17
Common stock-diluted	(0.60)	0.17
Common stock-basic and diluted	$ (0.60)	$ 0.17