Long-Term Obligations and Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Long-Term Obligations and Commitments [Abstract]

Long-Term Obligations

The carrying value of our long-term obligations was as follows (in thousands):

	December 31,
	2017			2016
1 percent convertible senior notes	$	533,111		$	500,511
Long-term mortgage debt		59,771			—
Long-term financing liability for leased facility		—			72,359
Principal balance of fixed rate note with Morgan Stanley		12,500			12,500
Leases and other obligations		2,095			3,735
Total	$	607,477		$	589,105
Less: current portion		(1,621	)		(1,185	)
Total Long-Term Obligations	$	605,856		$	587,920

Convertible Notes

At December 31, 2017, we had a nominal amount of our 2¾ percent convertible senior notes outstanding. At December 31, 2017 we had the following 1 percent convertible senior notes outstanding (amounts in millions except price per share data):

	1 Percent Convertible Senior Notes
Outstanding balance	$	685.5
Original issue date ($500 million of principal)	November 2014
Additional issue date ($185.5 million of principal)	December 2016
Maturity date	November 2021
Interest rate	1 percent
Conversion price per share	$	66.81
Total shares of common stock subject to conversion		10.3

We account for our convertible notes using an accounting standard that requires us to assign a value to our convertible debt equal to the estimated fair value of similar debt instruments without the conversion feature and to record the remaining portion in equity. As a result, we recorded our convertible notes at a discount, which we are amortizing as additional non-cash interest expense over the expected life of the respective debt. We determined our nonconvertible debt borrowing rate using a combination of the present value of the debt’s cash flows and a Black-Scholes valuation model. The following table summarizes the nonconvertible borrowing rate, effective interest rate and amortization period of our debt discount for our convertible notes:

	1 Percent Convertible Senior Notes Issued in November 2014	1 Percent Convertible Senior Notes Issued in December 2016
Nonconvertible debt borrowing rate	7.4 percent	6.8 percent
Effective interest rate	7.8 percent	7.2 percent
Amortization period of debt discount	7 years	5 years

The following table summarizes information about the equity and liability components of our outstanding 1 percent convertible notes (in thousands). We measured the fair values of the convertible notes outstanding based on quoted market prices, which is a Level 2 measurement:

	December 31,
	2017		2016
Fair value of outstanding notes	$	727,420	$	700,969
Principal amount of convertible notes outstanding	$	685,450	$	685,450
Unamortized portion of debt discount	$	144,112	$	175,699
Long-term debt	$	533,111	$	500,511
Carrying value of equity component	$	219,011	$	219,011

Maturity Schedules

Annual debt and other obligation maturities, including fixed and determinable interest, at December 31, 2017 are as follows (in thousands):

2018	$	9,617
2019		22,082
2020		9,330
2021		694,774
2022		2,809
Thereafter		71,603
Subtotal	$	810,215
Less: current portion		(53	)
Less: fixed and determinable interest		(51,465	)
Less: unamortized portion of debt discount		(144,791	)
Plus: Deferred rent		165
Total	$	614,071

Future Minimum Payments Under Operating Leases

Annual future minimum payments under operating leases as of December 31, 2017 are as follows (in thousands):

	Operating Leases
2018	$	864
2019		636
2020		477
2021		147
Total minimum payments	$	2,124