Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Cash flows from operating activities
Net income	$ 1,844		$ 1,301
Adjustments to reconcile net income to net cash flows from operating activities
Net realized (gains) losses	(310)		134
Amortization of premiums/discounts on fixed maturities	134		103
Deferred income taxes	98		1
Unpaid losses and loss expenses	(304)		(644)
Unearned premiums	693		780
Future policy benefits	117		54
Insurance and reinsurance balances payable	182		(60)
Accounts payable, accrued expenses, and other liabilities	230		(9)
Income taxes payable	20		0
Insurance and reinsurance balances receivable	(611)		(551)
Reinsurance recoverable on losses and loss expenses	538		626
Reinsurance recoverable on policy benefits	2		48
Deferred policy acquisition costs	(268)		(159)
Prepaid reinsurance premiums	(179)		(283)
Other	(378)		42
Net cash flows from operating activities	1,808		1,383
Cash flows from investing activities
Purchases of fixed maturities available for sale	(10,915)		(11,522)
Purchases of to be announced mortgage-backed securities	(26)		(165)
Purchases of fixed maturities held to maturity	(299)		(136)
Purchases of equity securities	(194)		(93)
Sales of fixed maturities available for sale	5,370		7,840
Sales of to be announced mortgage-backed securities	26		192
Sales of equity securities	62		33
Maturities and redemptions of fixed maturities available for sale	4,112		2,280
Maturities and redemptions of fixed maturities held to maturity	908		739
Net derivative instruments settlements	(317)		(133)
Acquisition of subsidiaries (net of cash acquired of $38 in 2013)	(977)		(30)
Other	(126)		(255)
Net cash flows used for investing activities	(2,376)		(1,250)
Cash flows from financing activities
Dividends paid on Common Shares	(169)		(318)
Common Shares repurchased	(212)		(11)
Proceeds from issuance of long-term debt	947		0
Proceeds from issuance of short-term debt	1,570		1,532
Repayment of short-term debt	(1,570)		(1,381)
Proceeds from share-based compensation plans, including windfall tax benefits	62		55
Other	30		0
Net cash flows from financing activities	658		(123)
Effect of foreign currency rate changes on cash and cash equivalents	(26)		(7)
Net increase (decrease) in cash	64		3
Cash - beginning of period	615	[1]	614
Cash - end of period	679	[2]	617
Supplemental cash flow information
Taxes paid	88		259
Interest paid	$ 117		$ 119

[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.

[2] 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 June 30, 2013, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.