Fair Value of Financial Instruments Fair value by balance sheet grouping table (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments

The carrying amount and fair value of our long-term debt, including current maturities, is as follows:

	March 31, 2017								December 31, 2016
Millions of dollars	Level 1		Level 2		Total fair value		Carrying value		Level 1		Level 2		Total fair value		Carrying value
Long-term debt	$	753	$	11,209	$	11,962	$	10,909	$	753	$	12,812	$	13,565	$	12,377