7. DEBT

Our debt consists of:

	December 31,
(In thousands)	2016			2015
Convertible subordinated notes due 2023	$	240,984		$	255,109
Non-recourse notes due 2029		487,189			493,162

Total debt		728,173			748,271
Unamortized debt issuance cost		(12,080	)		(15,140	)
Current portion of non-recourse notes due 2029		(7,752	)		—

Net long-term debt	$	708,341		$	733,131

Convertible Subordinated Notes Due 2023

In January 2013, we completed an underwritten public offering of $287.5 million aggregate principal amount of unsecured convertible subordinated notes, which will mature on January 15, 2023 (the "2023 Notes"). The financing raised proceeds, net of issuance costs, of approximately $281.2 million, less $36.8 million to purchase two privately-negotiated capped call option transactions in connection with the issuance of the notes. The 2023 Notes bear interest at the rate of 2.125% per year that is payable semi-annually in arrears in cash on January 15 and July 15 of each year, beginning on July 15, 2013.

The 2023 Notes were convertible, at the option of the holder, into shares of our common stock at an initial conversion rate of 35.9903 shares per $1,000 principal amount of the 2023 Notes, subject to adjustment in certain circumstances, which represents an initial conversion price of approximately $27.79 per share.

In connection with the offering of the 2023 Notes, we entered into two privately-negotiated capped call option transactions with a single counterparty. The capped call option transaction is an integrated instrument consisting of a call option on our common stock purchased by us with a strike price equal to the initial conversion price of $27.79 per share for the underlying number of shares and a cap price of $38.00 per share, both of which are subject to adjustments consistent with the 2023 Notes. The cap component is economically equivalent to a call option sold by us for the underlying number of shares with an initial strike price of $38.00 per share. As an integrated instrument, the settlement of the capped call coincides with the due date of the convertible debt. Upon settlement, we would receive from our hedge counterparty a number of shares of our common shares that would range from zero, if the stock price was below $27.79 per share, to a maximum of 2,779,659 shares, if the stock price is above $38.00 per share. However, if the market price of our common stock, as measured under the terms of the capped call transactions, exceeds $38.00 per share, there is no incremental anti-dilutive benefit from the capped call.

Following the Spin-Off of Theravance Biopharma in June 2014, the partial conversion by certain holders of the 2023 Notes in July 2014, and dividends declared and paid in 2014 and 2015, the conversion rate with respect to our 2023 Notes was adjusted in total to 50.5818 shares of our common stock per $1,000 principal amount of the 2023 Notes, which represents a conversion price of approximately $19.77 per share. As a result of the conversion rate adjustments, the capped call strike price and cap price were also adjusted accordingly to $19.77 and $27.04.

For the year ending December 31, 2016, we retired a portion of our 2023 Notes with a face value of $14.1 million and carrying value of $13.9 million by way of purchase in the open market. The 2023 Notes were purchased for a total settlement price of $11.6 million resulting in a gain of $2.3 million, which is included in other income (expense), net in the condensed consolidated statement of operations. As a result of the partial retirement of our 2023 Notes, we entered into partial termination agreement of the capped call option transaction described above. The partial termination agreement of the capped call option transaction enabled us to receive $0.6 million from the counterparty, which was recorded as an increase in additional paid-in capital in our condensed consolidated balance sheets as of December 31, 2016.

Non-Recourse Notes Due 2029

In April 2014, we entered into certain note purchase agreements relating to the private placement of $450.0 million aggregate principal amount of non-recourse fixed rate term notes due 2029 (the "2029 Notes") issued by our wholly-owned subsidiary.

The 2029 Notes are secured by a security interest in a segregated bank account established to receive 40% of royalties due to us under the LABA Collaboration with GSK commencing on April 1, 2014 and ending upon the earlier of full repayment of principal or May 15, 2029. The amounts in the segregated bank account can only be used to make interest and principal payments on the 2029 Notes. As of December 31, 2016 and 2015, the balance of the segregated bank account was not material.

The 2029 Notes bear an annual interest rate of 9%, with interest and principal paid quarterly beginning November 15, 2014. The 2029 Notes may be redeemed at any time prior to maturity, in whole or in part, at specified redemption premiums. Prior to May 15, 2016, in the event that the specified portion of royalties received in a quarter is less than the interest accrued for the quarter, the principal amount of the 2029 Notes increased by the interest shortfall amount for that period, and considered as payment in kind ("PIK"). Since issuance, $44.0 million of interest expense has been added to the principal balance of the 2029 Note, of which $0.9 million and $22.7 million was added during the years ended December 31, 2016 and 2015, respectively. During the year ended December 31, 2016, the principal balance of the 2029 Notes was paid down by $6.8 million with the payments received from the royalty revenues generated in the previous quarters ended June 30 and September 30, 2016. Since the principal and interest payments on the 2029 Notes are based on royalties from product sales recorded by GSK, which will vary from quarter to quarter and are unknown to us, the 2029 Notes may be repaid prior to the final maturity date in 2029. The 2029 Notes can be prepaid subject to a prepayment premium of 5% until April 17, 2016, 2.5% thereafter until April 17, 2017, and without premium afterwards.

In connection with the sale of the 2029 Notes, we incurred approximately $15.3 million in debt issuance costs, which are being amortized to interest expense over the estimated life of the 2029 Notes.

As of December 31, 2016, the principal balance of the 2029 Notes was $487.2 million, which will be partially paid down by $7.8 million in the next quarterly payment expected to be made in February 2017. This payment is based on our royalty revenues of $46.8 million for the three months ended December 31, 2016