Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2015

Fair Value Disclosures [Abstract]

Estimated Fair Value of Financial Instruments, Debt Instruments [Table Text Block]

	December 31, 2015				December 31, 2014
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Financial liabilities:
Long-term debt, including current portion	$	4,880	$	5,108	$	5,052	$	5,441