Schedule VI (Details) - Consolidated Property and Casualty Insurance Entity [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplementary Information Concerning Property-Casualty Insurance Operations
Deferred acquisition costs	$ 2,120	$ 2,025	$ 1,923
Claims and claim adjustment expense reserves	50,653	49,633	47,929
Discount from reserves for unpaid claims	1,158	1,102	1,083
Unearned premiums	13,555	12,915	12,329
Earned premiums	27,059	25,683	24,534
Net investment income	2,474	2,397	2,302
Claims and claim adjustment expenses incurred related to current year	18,614	17,846	15,675
Claims and claim adjustment expenses incurred related to prior year	(406)	(458)	(680)
Amortization of deferred acquisition costs	4,381	4,166	3,985
Paid claims and claim adjustment expenses	17,060	16,043	14,796
Net written premiums	$ 27,708	$ 26,219	$ 24,958