Debt and Credit Facilities (Tables)

3 Months Ended

Mar. 31, 2020

Long-term Debt, Unclassified [Abstract]

Schedule of Long-term Debt Instruments

Summary of Total Debt			March 2020		December 2019
Senior unsecured notes:
	Rate	Due
	4.375%	January 15, 2020	$	—	$	500
	Variable	November 30, 2020	328		333
	2.625%	March 15, 2021	749		749
	1.125%	November 30, 2023	599		609
	3.375%	May 15, 2024	588		587
	0.250%	December 3, 2024	923		938
	3.375%	November 1, 2025	746		746
	3.500%	March 15, 2026	991		991
	2.125%	November 30, 2027	815		829
	3.650%	March 7, 2028	596		596
	0.750%	March 1, 2029	869		884
	2.625%	November 30, 2030	700		712
	1.000%	December 3, 2031	809		823
	4.100%	April 1, 2043	392		391
	4.375%	May 15, 2044	395		395
	4.625%	March 15, 2046	981		981
Other			26		26
Total debt			$	10,507	$	11,090
Less current maturities of debt			1,103		859
Total long-term debt			$	9,404	$	10,231

	March 2020		December 2019
Unamortized debt issuance costs	$	56	$	58
Available secured borrowing capacity	$	1,403	$	1,403
Fair value of senior unsecured notes	$	10,904	$	11,910