Debt (Tables)

6 Months Ended

Jun. 30, 2016

Debt Disclosure [Abstract]

Schedule of debt

(in millions)	June 30, 2016		December 31, 2015
5.9% Senior Notes, due 2017 1	$	400	399
2.5% Senior Notes, due 2018 2	398		398
3.3% Senior Notes, due 2020 3	695		695
4.0% Senior Notes, due 2025 4	690		690
4.4% Senior Notes, due 2026 5	891		890
6.55% Senior Notes, due 2037 6	396		396
Commercial paper	309		143
Total debt	3,779		3,611
Less: short-term debt including current maturities	309		143
Long-term debt	$	3,470	$	3,468

¹  Interest payments are due semiannually on April 15 and October 15, and as of June 30, 2016, the unamortized debt discount and issuance costs are less than $1 million.

²  Interest payments are due semiannually on February 15 and August 15, and as of June 30, 2016, the unamortized debt discount and issuance costs total $2 million.

³  Interest payments are due semiannually on February 14 and August 14, and as of June 30, 2016, the unamortized debt discount and issuance costs total $5 million.

⁴  Interest payments are due semiannually on June 15 and December 15, and as of June 30, 2016, the unamortized debt discount and issuance costs total $10 million.

⁵  Interest payments are due semiannually on February 15 and August 15, and as of June 30, 2016, the unamortized debt discount and issuance costs total $9 million.

⁶  Interest payments are due semiannually on May 15 and November 15, and as of June 30, 2016, the unamortized debt discount and issuance costs total $4 million.