Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 7,116,100	$ 30,801,137	$ 20,990,033
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and other non-cash items	6,109,869	6,587,282	6,740,346
Net realized investment gains	(5,705,255)	(2,525,575)	(1,934,424)
Equity in earnings of Donegal Financial Services Corporation	(1,621,605)	(1,086,157)	(1,277,229)
Changes in Assets and Liabilities:
Losses and loss expenses	70,007,137	28,459,481	39,946,703
Unearned premiums	37,401,313	36,562,025	20,846,840
Accrued expenses	(212,915)	5,786,216	3,030,848
Premiums receivable	(1,016,765)	(18,122,256)	(7,960,450)
Deferred policy acquisition costs	(3,980,664)	(4,200,808)	(3,809,780)
Deferred income taxes	11,889,970	2,030,865	168,395
Reinsurance receivable	(35,314,555)	(3,299,895)	(6,092,223)
Accrued investment income	(257,608)	(304,316)	(239,821)
Amounts due from affiliate	16,519,278	(12,762,087)	1,147,830
Reinsurance balances payable	(253,369)	889,122	(4,360,766)
Prepaid reinsurance premiums	(10,777,146)	(10,732,990)	2,349,278
Current income taxes	(9,826,855)	379,406	(906,179)
Other, net	(113,482)	(22,628)	(2,235,228)
Dividends received from Donegal Financial Services Corporation	1,036,750	1,591,300	1,783,700
Net adjustments	73,884,098	29,228,985	47,197,840
Net cash provided by operating activities	81,000,198	60,030,122	68,187,873
Purchases of fixed maturities:
Held to maturity	(51,049,152)	(44,907,210)	(31,310,026)
Available for sale	(138,675,907)	(161,873,868)	(181,106,519)
Purchases of equity securities	(17,033,093)	(15,222,724)	(14,759,861)
Sales of fixed maturities:
Available for sale	10,081,785	55,731,299	40,321,838
Maturity of fixed maturities:
Held to maturity	20,577,326	19,488,644	28,575,153
Available for sale	99,544,479	82,586,588	66,744,045
Sales of equity securities	20,880,814	9,201,657	8,761,474
Net purchases of property and equipment	(1,090,726)	(384,207)	(151,536)
Net (purchases) sales of short-term investments	(1,678,908)	4,061,475	6,861,166
Net cash used in investing activities	(58,443,382)	(51,318,346)	(76,064,266)
Cash Flows from Financing Activities:
Issuance of common stock	15,511,457	13,822,228	15,516,870
Cash dividends paid	(14,822,052)	(14,085,934)	(14,455,167)
Purchases of treasury stock			(28,124,675)
Payments on lines of credit	(10,000,000)	(12,000,000)	(9,500,000)
Borrowings under lines of credit			37,000,000
Net cash (used in) provided by financing activities	(9,310,595)	(12,263,706)	437,028
Net increase (decrease) in cash	13,246,221	(3,551,930)	(7,439,365)
Cash at beginning of year	24,587,214	28,139,144	35,578,509
Cash at end of year	$ 37,833,435	$ 24,587,214	$ 28,139,144