LONG-TERM DEBT

During 2017, we issued $7.29 billion of medium-term notes, of which $4.89 billion were at fixed interest rates and $2.40 billion were at floating interest rates, primarily indexed to LIBOR. At December 31, 2017, the outstanding medium-term notes had remaining maturities ranging up to 9 years. Debt issuance costs are capitalized and amortized to Interest expense using the straight-line method over the term of the debt issuance. The balance of our medium-term notes contains unamortized fair value adjustments for debt in a fair value hedge relationship.

Long-term debt outstanding as of December 31, was comprised of the following:



(Millions of dollars)
	2017				2016
	Balance			Avg. Rate	Balance			Avg. Rate
Medium-term notes	$	21,362		2.5%	$	19,731		2.4%
Unamortized discount and debt issuance costs	(59		)		(64		)
Medium-term notes, net	21,303				19,667
Bank borrowings	803			5.0%	870			4.5%
Total	$	22,106			$	20,537

Long-term debt outstanding as of December 31, 2017, matures as follows:



(Millions of dollars)
2018	$	6,188
2019	5,681
2020	4,290
2021	1,740
2022	2,048
Thereafter	2,159
Total	$	22,106

The above table includes $148 million of medium-term notes that could be called by us at some point in the future at par.

During September 2016, $381 million of medium-term notes with varying interest rates and maturity dates were exchanged for $366 million of 1.93 percent medium-term notes due in 2021 and $15 million in cash. In addition, a debt exchange premium of $33 million was paid.