Insurance (Tables)

12 Months Ended

Dec. 31, 2018

Insurance [Abstract]

Schedule of Insurance Assets [Table Text Block]

Cash, cash equivalents, and marketable securities related to insurance activities at December 31 were as follows (in millions):

	2017		2018
Cash and cash equivalents	$	162	$	59
Marketable securities	449		649
Total cash, cash equivalents, and marketable securities	$	611	$	708

Schedule of Insurance Underwriting Losses and Expenses [Table Text Block]

The components of insurance expenses for the years ended December 31 were as follows (in millions):

	2016			2017			2018
Insurance losses	$	146		$	143		$	101
Loss adjustment expenses	5			8			5
Reinsurance income and other expenses, net	(26		)	(27		)	(29		)
Insurance expenses	$	125		$	124		$	77

Schedule of the Effect of Reinsurance Premiums Written and Earned [Table Text Block]

Insurance premiums written and earned for the years ended December 31 were as follows (in millions):

	2016						2017						2018
	Written			Earned			Written			Earned			Written			Earned
Direct	$	371		$	298		$	385		$	320		$	392		$	346
Assumed	—			—			—			—			—			—
Ceded	(215		)	(142		)	(227		)	(162		)	(225		)	(179		)
Net premiums	$	156		$	156		$	158		$	158		$	167		$	167