Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2018

Line of Credit Facility [Abstract]

Schedule of Short-term Debt [Table Text Block]

Short-term borrowings under these credit facilities and related interest rates are reflected in the following table (dollars in millions). The Company had no short-term borrowings during 2018.

	Years Ended December 31,
	2018			2017			2016
Average daily amount of short-term debt outstanding	$	—		$	—		$	1
Weighted daily average interest rate *	—		%	—		%	0.7		%
Maximum amount outstanding during the year	$	—		$	—		$	23

* Excludes the effect of commitment fees, facility fees and other financing fees.