Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets
Fixed maturities available for sale, at fair value (amortized cost - $45,470 and $44,666) (includes hybrid financial instruments of $274 and $309)	$ 47,947	$ 47,306
Fixed maturities held to maturity, at amortized cost (fair value - $7,213 and $7,633)	6,867	7,270
Equity securities, at fair value (cost - $781 and $707)	832	744
Short-term investments, at fair value and amortized cost	2,893	2,228
Other investments (cost - $2,544 and $2,465)	2,820	2,716
Total investments	61,359	60,264
Cash	855	615	[1]
Securities lending collateral	1,786	1,791
Accrued investment income	545	552
Insurance and reinsurance balances receivable	4,154	4,147
Reinsurance recoverable on losses and loss expenses	11,530	12,078
Reinsurance recoverable on policy benefits	231	241
Deferred policy acquisition costs	1,966	1,873
Value of business acquired	583	614
Goodwill and other intangible assets	4,909	4,975
Prepaid reinsurance premiums	1,653	1,617
Deferred tax assets	505	453
Investments in partially-owned insurance companies (cost - $446 and $451)	449	454
Other assets	2,936	2,871
Total assets	93,461	92,545
Liabilities
Unpaid losses and loss expenses	37,082	37,946
Unearned premiums	7,019	6,864
Future policy benefits	4,465	4,470
Insurance and reinsurance balances payable	3,402	3,472
Securities lending payable	1,789	1,795
Accounts payable, accrued expenses, and other liabilities	5,701	5,377
Income taxes payable	43	20
Short-term debt	1,402	1,401
Long-term debt	4,307	3,360
Trust preferred securities	309	309
Total liabilities	65,519	65,014
Commitments and contingencies
Shareholders' equity
Common Shares (CHF 28.43 and CHF 28.89 par value; 342,832,412 shares issued; 340,045,256 and 340,321,534 shares outstanding)	9,423	9,591
Common Shares in treasury (2,787,156 and 2,510,878 shares)	(212)	(159)
Additional paid-in capital	5,095	5,179
Retained earnings	10,986	10,033
Accumulated other comprehensive income (AOCI)	2,650	2,887
Total shareholders' equity	27,942	27,531
Total liabilities and shareholders' equity	$ 93,461	$ 92,545

[1] ACE maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various ACE entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual ACE accounts are translated daily into a single currency and pooled on a notional basis. Individual ACE entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2012, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.