Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Components of the Property and Casualty Group's and EFL's deferred policy acquisition costs assets
Deferred policy acquisition costs asset, beginning of year	$ 566
Amortized deferred policy acquisition costs	(849)	(778)	(715)
Deferred policy acquisition costs asset, end of year	595	566
Property and Casualty Group
Components of the Property and Casualty Group's and EFL's deferred policy acquisition costs assets
Deferred policy acquisition costs asset, beginning of year	402	364
Capitalized deferred policy acquisition costs	874	801
Amortized deferred policy acquisition costs	(836)	(763)
Deferred policy acquisition costs asset, end of year	440	402
Erie Family Life Insurance Company (EFL)
Components of the Property and Casualty Group's and EFL's deferred policy acquisition costs assets
Deferred policy acquisition costs asset, beginning of year	164	140
Capitalized deferred policy acquisition costs	18	15
Amortized deferred policy acquisition costs	(13)	(15)
Change in shadow deferred policy acquisition costs	(14)	24
Deferred policy acquisition costs asset, end of year	$ 155	$ 164