Reserve for Property and Liability Insurance Claims and Claims Expense (Tables)

9 Months Ended

Sep. 30, 2018

Reserve for Property-Liability Insurance Claims and Claims Expense [Abstract]

Schedule of liability for unpaid claims and claims adjustment expense

Rollforward of the reserve for property and casualty insurance claims and claims expense
	Nine months ended September 30,
($ in millions)	2018			2017
Balance as of January 1	$	26,325		$	25,250
Less reinsurance recoverables	(6,471		)	(6,184		)
Net balance as of January 1	19,854			19,066
SquareTrade acquisition as of January 3, 2017	—			17
Incurred claims and claims expense related to:
Current year	16,893			16,971
Prior years	(135		)	(321		)
Total incurred	16,758			16,650
Claims and claims expense paid related to:
Current year	(10,124		)	(10,052		)
Prior years	(6,174		)	(5,784		)
Total paid	(16,298		)	(15,836		)
Net balance as of September 30	20,314			19,897
Plus reinsurance recoverables	6,625			7,257
Balance as of September 30	$	26,939		$	27,154