Income Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income taxes
Deferred income tax (benefit) expense	$ 198	$ 118	$ (105)
Provision for income taxes	519	280	90
Reconciliation of the provision for income taxes, with amounts determined by applying the statutory federal income tax rates to pre-tax income
Provision for income taxes	519	280	90
Indemnity
Income taxes
Current income tax expense	89	84	85
Deferred income tax (benefit) expense	(5)	(3)	0
Provision for income taxes	84	81	85
Reconciliation of the provision for income taxes, with amounts determined by applying the statutory federal income tax rates to pre-tax income
Income tax at statutory rates	86	84	89
Tax-exempt interest	(2)	(2)	(3)
Dividends received deduction	0	(1)	(1)
Erie Family Life losses			(1)
Other, net	0	0	1
Provision for income taxes	84	81	85
Exchange
Income taxes
Current income tax expense	232	78	110
Deferred income tax (benefit) expense	203	121	(105)
Provision for income taxes	435	199	5
Reconciliation of the provision for income taxes, with amounts determined by applying the statutory federal income tax rates to pre-tax income
Income tax at statutory rates	462	230	37
Tax-exempt interest	(13)	(13)	(15)
Dividends received deduction	(14)	(14)	(13)
Return to provision adjustments	(1)	(3)	(5)
Other, net	1	(1)	1
Provision for income taxes	$ 435	$ 199	$ 5