Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Schedule of Marketable Securities [Table Text Block]

	March 31, 2017						December 31, 2016
	Cost		Unrealized Gain (Loss)		Fair Value		Cost		Unrealized Gain (Loss)		Fair Value
U.S. government securities	$	2	$	—	$	2	$	2	$	—	$	2
Corporate securities	3				3		2				2
Certificates of deposit	22				22		22				22
Other	4				4		4				4
Total marketable securities	$	31	$	—	$	31	$	30	$	—	$	30