Debt (Tables)

12 Months Ended

Dec. 31, 2015

Debt Disclosure [Abstract]

Summary of Short-term and Long-term Debt Outstanding

A summary of short-term and long-term debt outstanding is as follows:

(in millions)	December 31,
	2015		2014
5.9% Senior Notes, due 2017 1	$	399	$	399
2.5% Senior Notes, due 2018 2	398		—
3.3% Senior Notes, due 2020 3	695		—
4.0% Senior Notes, due 2025 4	690		—
4.4% Senior Notes, due 2026 5	890		—
6.55% Senior Notes, due 2037 6	396		396
Commercial paper	143		—
Total debt	3,611		795
Less: short-term debt including current maturities	143		—
Long-term debt	$	3,468	$	795

¹  Interest payments are due semiannually on April 15 and October 15, and as of December 31, 2015, the unamortized debt discount and issuance costs total $1 million.

²  Interest payments are due semiannually on February 15 and August 15, beginning on February 15, 2016, and as of December 31, 2015, the unamortized debt discount and issuance costs total $2 million.

³  Interest payments are due semiannually on February 14 and August 14, beginning on February 14, 2016, and as of December 31, 2015, 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 December 31, 2015, the unamortized debt discount and issuance costs total $10 million.

⁵  Interest payments are due semiannually on February 15 and August 15, beginning on February 15, 2016, and as of December 31, 2015, the unamortized debt discount and issuance costs total $10 million.

⁶  Interest payments are due semiannually on May 15 and November 15, and as of December 31, 2015, the unamortized debt discount and issuance costs total $4 million.