Contingencies, Commitments and Guarantees (details) (USD $)	9 Months Ended
	Sep. 30, 2011 years count	Dec. 31, 2010	Oct. 25, 2010
Contingencies, Commitments and Guarantees disclosure
Number of purported class action suits filed against TPC and other insurers in state court in West Virginia relative to asbestos direct action litigation	2
Maximum lump-sum payment included in the settlement reached in November 2003 relative to Statutory and Hawaii Actions	$ 412,000,000
Maximum payment required under May 2004 settlement resolving substantially all pending and similar future Common Law Claims relative to Statutory and Hawaii Actions	90,000,000
Number of putative class action lawsuits brought against a number of insurers relative to broker anti-trust litigation	4
Amount Company has agreed to pay under broker anti-trust litigation settlement	6,750,000
Judgment amount awarded to Company in reinsurance dispute			251,000,000
Pre-judgment interest amount awarded to Company in reinsurance dispute			169,000,000
Total judgment amount awarded to Company in reinsurance dispute			420,000,000
Post-judgment interest rate accruing on judgment against non-settling defendants	9.00%
Unfunded commitments to private equity limited partnerships and real estate partnerships	$ 1,170,000,000	$ 1,260,000,000
Period range for term of indemnification provisions arising from sales of business entities, minimum (in years)	2