Debt and Lines of Credit (Tables)

9 Months Ended

Sep. 30, 2017

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

Long-term debt outstanding is as follows:

	September 30,			December 31,
	2017			2016
Notes due 2017 at 0.875%	$	—		$	250
Notes due 2017 at 6.60% (assumed with National acquisition)		—			375
Notes due 2018 at 1.00%		500			500
Notes due 2019 at 1.65%		750			750
Notes due 2020 at 1.75%		500			500
Notes due 2021 at 2.75%		550			250
Notes due 2022 at 1.85%		500			500
Notes due 2023 at 2.25%		500			500
Notes due 2024 at 2.625%		300			—
Total debt		3,600			3,625
Net unamortized discounts, premiums and debt issuance costs		(17	)		(16	)
Total debt, including net unamortized discounts, premiums and debt issuance costs		3,583			3,609
Current portion of long-term debt		(499	)		(631	)
Long-term debt	$	3,084		$	2,978