December 31, 2016				December 31, 2015
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	$ 12,812	$ 13,565	$ 12,377	$ 1,009	$ 14,947	$ 15,956	$ 15,346