Debt (Tables)

3 Months Ended

Mar. 31, 2019

Debt Disclosure [Abstract]

Schedule of Debt

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

(in millions)	March 31, 2019		December 31, 2018
3.3% Senior Notes, due 2020 1	698		698
4.0% Senior Notes, due 2025 2	693		693
4.4% Senior Notes, due 2026 3	893		892
2.95% Senior Notes, due 2027 4	493		493
6.55% Senior Notes, due 2037 5	396		396
4.5% Senior Notes, due 2048 6	490		490
Long-term debt	$	3,663	$	3,662

¹  Interest payments are due semiannually on February 14 and August 14, and as of March 31, 2019, the unamortized debt discount and issuance costs total $2 million.

²  Interest payments are due semiannually on June 15 and December 15, and as of March 31, 2019, the unamortized debt discount and issuance costs total $7 million.

³  Interest payments are due semiannually on February 15 and August 15, and as of March 31, 2019, the unamortized debt discount and issuance costs total $7 million.

⁴  Interest payments are due semiannually on January 22 and July 22, and as of March 31, 2019, the unamortized debt discount and issuance costs total $7 million.

⁵  Interest payments are due semiannually on May 15 and November 15, and as of March 31, 2019, the unamortized debt discount and issuance costs total $4 million.

⁶  Interest payments are due semiannually on May 15 and November 15, beginning on November 15, 2018, and as of March 31, 2019, the unamortized debt discount and issuance costs total $10 million.