Debt and lines of credit

Short-term borrowings

We maintain a line of credit to support commercial paper borrowings, if any, and to provide additional liquidity through bank loans. As of December 31, 2014, we had a variable-rate revolving credit facility from a consortium of investment-grade banks that allows us to borrow up to $2 billion through March 2019. The interest rate on borrowings under this credit facility, if drawn, is indexed to the applicable London Interbank Offered Rate (LIBOR). As of December 31, 2014, our credit facility was undrawn and we had no commercial paper outstanding.

Long-term debt

In March 2014, we issued an aggregate principal amount of $500 million of fixed-rate long-term debt, with $250 million due in 2017 and $250 million due in 2021. We incurred $3 million of issuance and other related costs, which are being amortized to Interest and debt expense over the term of the debt. The proceeds of the offering were $498 million, net of the original issuance discount and were used toward the repayment of the $1.0 billion of debt that matured in May 2014.

In May 2013, we issued an aggregate principal amount of $1.0 billion of fixed-rate long-term debt, with $500 million due in 2018 and $500 million due in 2023. We incurred $6 million of issuance and other related costs that are being amortized to Interest and debt expense over the term of the debt. The proceeds of the offering were $986 million, net of the original issuance discount and were used toward the repayment of $1.5 billion of maturing debt, including floating-rate notes. In connection with this repayment, we settled a floating-to-fixed interest rate swap, associated with the maturing debt.

In August 2012, we issued an aggregate principal amount of $1.5 billion of fixed-rate long-term debt, with $750 million due in 2015 and $750 million due in 2019. The proceeds of the offering were $1.492 billion, net of the original issuance discount. We also incurred $7 million of issuance and other related costs that are being amortized to Interest and debt expense over the term of the debt.

Long-term debt outstanding as of December 31, 2014 and 2013 is as follows:



	December 31,
	2014			2013
Notes due 2014 at 1.375%	$	—		$	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 2017 at 0.875%	250			—
Notes due 2018 at 1.00%	500			500
Notes due 2019 at 1.65%	750			750
Notes due 2021 at 2.75%	250			—
Notes due 2023 at 2.25%	500			500
	4,625			5,125
Net unamortized premium	17			33
Current portion of long-term debt	(1,001		)	(1,000		)
Long-term debt	$	3,641		$	4,158

Interest and debt expense was $94 million in 2014, $95 million in 2013 and $85 million in 2012. This was net of the amortization of the debt premium and other debt issuance costs. Cash payments for interest on long-term debt were $102 million in both 2014 and 2013 and $97 million in 2012. Capitalized interest was not material.