LONG-TERM DEBT (Tables)

12 Months Ended

Dec. 31, 2017

LONG-TERM DEBT

Long-term debt

Balance at December 31, (in millions)	2017		2016
1.50% senior notes due 2018	$	500	$	500
9.25% senior debentures due 2019	116		116
4.10% senior notes due 2021	1,249		1,249
3.125% senior notes due 2022	813		813
2.60% senior notes due 2022	400		400
2.70% senior notes due 2023	1,191		1,191
8.75% medium-term notes due 2023	22		22
3.50% senior notes due 2025	750		750
3.40% senior notes due 2026	1,150		1,150
3.00% senior notes due 2027	750		750
7.20% senior debentures due 2028	82		82
8.45% senior debentures due 2029	116		116
4.625% senior notes due 2045	750		750
4.40% senior notes due 2046	1,200		1,200
4.10% senior notes due 2047	750		750
Variable rate bonds due 2030 (1.8% and 0.9% as of December 31, 2017 and 2016, respectively )	68		68
	9,907		9,907
Less:
Unamortized discount, net	(32)		(36)
Debt issuance costs	(47)		(52)
Current maturities	(500)		—
Total	$	9,328	$	9,819