Unpaid losses and loss expenses (Tables)

12 Months Ended

Dec. 31, 2012

Unpaid Losses And Loss Expenses [Abstract]

Schedule Of Unpaid Losses And Loss Expenses Roll Forward

The following table presents a reconciliation of unpaid losses and loss expenses:



	Years Ended December 31
(in millions of U.S. dollars)	2012				2011				2010
Gross unpaid losses and loss expenses, beginning of year		$	37,477			$	37,391			$	37,783
Reinsurance recoverable on unpaid losses⁽¹⁾		(11,602		)		(12,149		)		(12,745		)
Net unpaid losses and loss expenses, beginning of year		25,875				25,242				25,038
Acquisition of subsidiaries		14				92				145
Total		25,889				25,334				25,183
Net losses and loss expenses incurred in respect of losses occurring in:
Current year		10,132				10,076				8,082
Prior years		(479		)		(556		)		(503		)
Total		9,653				9,520				7,579
Net losses and loss expenses paid in respect of losses occurring in:
Current year		4,325				4,209				2,689
Prior years		4,894				4,657				4,724
Total		9,219				8,866				7,413
Foreign currency revaluation and other		224				(113		)		(107		)
Net unpaid losses and loss expenses, end of year		26,547				25,875				25,242
Reinsurance recoverable on unpaid losses⁽¹⁾		11,399				11,602				12,149
Gross unpaid losses and loss expenses, end of year		$	37,946			$	37,477			$	37,391
⁽¹⁾ Net of provision for uncollectible reinsurance.

Schedule Of Asbestos Environmental Loss Roll Forward

The table below presents a roll-forward of consolidated A&E loss reserves (excluding other run-off liabilities), allocated loss expense reserves for A&E exposures, and the provision for uncollectible paid and unpaid reinsurance recoverables:



	Asbestos								Environmental								Total
(in millions of U.S. dollars)	Gross				Net				Gross				Net				Gross				Net
Balance at December 31, 2011⁽¹⁾		$	2,086			$	1,142			$	245			$	162			$	2,331			$	1,304
Incurred activity		211				95				40				39				251				134
Paid activity		(440		)		(275		)		(78		)		(61		)		(518		)		(336		)
Balance at December 31, 2012		$	1,857			$	962			$	207			$	140			$	2,064			$	1,102


⁽¹⁾	Balances at December 31, 2011 have been adjusted to present claims in a manner consistent with balances disclosed at December 31, 2012.

Schedule Of Brandywine Asbestos Environmental Loss Roll Forward

The following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of Brandywine operations only, including the impact of the Brandywine NICO Agreement for the year ended December 31, 2012:



	Brandywine													NICO Coverage					Net of NICO Coverage
(in millions of U.S. dollars)	A&E				Other				⁽¹⁾	Total				NICO Coverage				⁽²⁾	Net of NICO Coverage
Balance at December 31, 2011⁽³⁾		$	1,032			$	458				$	1,490			$	386			$	1,104
Incurred activity		110				19					129				—				129
Paid activity		(290		)		(56		)			(346		)		(368		)		22
Balance at December 31, 2012		$	852			$	421				$	1,273			$	18			$	1,255


⁽¹⁾	Other consists primarily of workers' compensation, non-A&E general liability losses, and provision for uncollectible reinsurance on non-A&E business.


⁽²⁾	NICO Coverage at December 31, 2011 was reduced to reflect $238 million of advances from NICO on uncollected inuring reinsurance recoverables as payments reducing the limit.


⁽³⁾	Balances at December 31, 2011 have been adjusted to present claims in a manner consistent with balances disclosed at December 31, 2012.

Schedule Of Westchester Specialty Asbestos Environmental Loss Roll Forward

The following table presents a roll-forward of net loss reserves, allocated loss expense reserves, and provision for uncollectible paid and unpaid reinsurance recoverables in respect of 1996 and prior Westchester Specialty operations that are the subject business of the NICO covers for the year ended December 31, 2012:



	Westchester Specialty										NICO Coverage			Net of NICO Coverage
(in millions of U.S. dollars)	A&E			Other				Total			NICO Coverage			Net of NICO Coverage
Balance at December 31, 2011⁽¹⁾		$	144		$	54			$	198		$	165		$	33
Incurred activity		22			(6		)		16			12			4
Paid activity		(15)			(4)				(19)			(19)			—
Balance at December 31, 2012		$	151		$	44			$	195		$	158		$	37


⁽¹⁾	Balances at December 31, 2011 have been adjusted to present claims in a manner consistent with balances disclosed at December 31, 2012.