Indemnity Supplemental Information (Details) (USD $) In Millions, unless otherwise specified									12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013 Indemnity	Dec. 31, 2012 Indemnity	Dec. 31, 2011 Indemnity	Dec. 31, 2010 Indemnity	Dec. 31, 2013 Indemnity Erie Family Life Insurance Company (EFL)	Dec. 31, 2012 Indemnity Erie Family Life Insurance Company (EFL)	Dec. 31, 2013 Exchange	Dec. 31, 2012 Exchange	Dec. 31, 2013 Reclassifications and eliminations	Dec. 31, 2012 Reclassifications and eliminations
Available-for-sale securities, at fair value:
Fixed maturities	$ 8,688	$ 8,159			$ 526	$ 452					$ 8,162	$ 7,707
Equity securities	869	1,000			50	55					819	945
Trading securities, at fair value	3,202	2,417			0	0					3,202	2,417
Limited partnerships	1,086	1,217			146	180					940	1,037
Other invested assets	21	21			1	1					20	20
Total investments	13,866	12,814			723	688					13,143	12,126
Cash and cash equivalents	452	400	185	430	49	12	11	310			403	388
Premiums receivable from policyholders	1,167	1,062									1,167	1,062
Reinsurance recoverable	172	168									172	168
Deferred income tax asset	2	37			2	37					0	0
Deferred acquisition costs	566	504									566	504
Other assets	451	456			114	117					337	339
Receivables from the Exchange and other affiliates					300	281			4	3			(300)	(281)
Note receivable from EFL					25	25			25				(25)	(25)
Total assets	16,676	15,441			1,213	1,160					15,788	14,587	(325)	(306)
Liabilities
Losses and loss expense reserves	3,747	3,598									3,747	3,598
Life policy and deposit contract reserves	1,758	1,708									1,758	1,708
Unearned premiums	2,598	2,365									2,598	2,365
Deferred income tax liability	450	365			0	0					450	365
Other liabilities, adjusted for consolidation presentation	573	614			479	518					419	402	(325)	(306)
Total liabilities	9,126	8,650			479	518					8,972	8,438	(325)	(306)
Shareholders' equity and noncontrolling interest
Total Indemnity shareholders’ equity	734	642			734	642
Noncontrolling interest in consolidated entity – Exchange	6,816	6,149									6,816	6,149
Total equity	7,550	6,791	6,293		734	642					6,816	6,149
Total liabilities, shareholders’ equity, and noncontrolling interest	16,676	15,441			1,213	1,160					15,788	14,587	(325)	(306)
Receivables from the Exchange					296	278
Note receivable from EFL, annual interest rate (as a percent)									6.70%
Note receivable from EFL, interest income recognized by Indemnity									$ 2	$ 2