Debt and lines of credit (Tables)

9 Months Ended

Sep. 30, 2013

Long-term Debt, Unclassified [Abstract]

Schedule of Long-term Debt Instruments

The following table summarizes the total long-term debt outstanding as of September 30, 2013 and December 31, 2012:

	September 30, 2013			December 31, 2012
Floating-rate notes due 2013 (swapped to a 0.922% fixed rate)	$	—		$	1,000
Notes due 2013 at 0.875%	—			500
Notes due 2014 at 1.375%	1,000			1,000
Notes due 2015 at 3.95% (assumed with National acquisition)	250			250
Notes due 2015 at 0.45%	750			750
Notes due 2016 at 2.375%	1,000			1,000
Notes due 2017 at 6.60% (assumed with National acquisition)	375			375
Notes due 2018 at 1.00%	500			—
Notes due 2019 at 1.65%	750			750
Notes due 2023 at 2.25%	500			—
	5,125			5,625
Add net unamortized premium	36			61
Less current portion of long-term debt	(1,000		)	(1,500		)
Total long-term debt	$	4,161		$	4,186