Goodwill and Other Intangible Assets Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Other Intangible Assets

Intangible assets and associated amortization expense were as follows at December 31:

millions	2018			2017
Gross carrying amount	$	980		$	1,013
Accumulated amortization	(139		)	(140		)
Net carrying amount	$	841		$	873
Amortization expense	$	32		$	31