Deferred Policy Acquisition and Sales Inducement Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred policy acquisition costs activity
Balance, beginning of year	$ 4,784	$ 4,191	$ 3,954
SquareTrade acquisition	0	0	66
Acquisition costs deferred	5,622	5,663	5,001
Amortization charged to income	(5,533)	(5,222)	(4,784)
Effect of unrealized gains and losses	(174)	152	(46)
Balance, end of year	4,699	4,784	4,191
Deferred sales inducement costs activity
Balance, beginning of year	34	36	40
Amortization charged to income	(5)	(4)	(4)
Effect of unrealized gains and losses	(2)	2	0
Balance, end of year	$ 27	$ 34	$ 36