Investments (Details 4) (Donegal Financial Services Corporation [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Donegal Financial Services Corporation [Member]
Balance sheets:
Total assets	$ 504,551		$ 504,551		$ 532,938
Total liabilities	429,538		429,538		466,940
Stockholders equity	75,013		75,013		65,998
Total liabilities and stockholders equity	504,551		504,551		532,938
Income statements:
Net income	$ 2,771	$ 2,129	$ 7,510	$ 2,830