Related Party (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Related Party Transactions
Cash settlements for payments made by Indemnity on the account of related parties	$ 113,033	$ 114,824	$ 358,800	$ 340,626
Erie Insurance Exchange (EIE)
Related Party Transactions
Cash settlements for payments made by Indemnity on the account of related parties	103,498	106,307	329,761	313,353
Erie Family Life Insurance Company (EFL)
Related Party Transactions
Cash settlements for payments made by Indemnity on the account of related parties	$ 9,535	$ 8,517	$ 29,039	$ 27,273