Long-Term Obligations and Commitments (Tables)

12 Months Ended

Dec. 31, 2015

Long-Term Obligations and Commitments [Abstract]

Long-Term Obligations

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

	December 31,
	2015			2014
1 percent convertible senior notes	$	347,214		$	327,486
2¾ percent convertible senior notes		50,361			48,014
Long-term financing liability for leased facility		72,217			71,731
Equipment financing arrangement		515			3,226
Leases and other obligations		2,341			7,325
Total	$	472,648		$	457,782
Less: current portion		(515	)		(2,882	)
Total Long-Term Obligations	$	472,133		$	454,900

Convertible Notes

At December 31, 2015 we had the following convertible debt outstanding (amounts in millions except price per share data):

	1 Percent Convertible Senior Notes		2¾ Percent Convertible Senior Notes
Outstanding balance	$	500	$	61
Issue date	November 2014		August 2012
Maturity date	November 2021		October 2019
Interest rate	1 percent		2¾ percent
Conversion price per share	$	66.81	$	16.63
Total shares of common stock subject to conversion		7.5		3.7

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	2¾ Percent Convertible Senior Notes
Nonconvertible debt borrowing rate	7.4 percent	8.0 percent
Effective interest rate	7.8 percent	8.8 percent
Amortization period of debt discount	7 years	7 years

The following table summarizes information about the equity and liability components of our outstanding 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,
	2015		2014
2¾ Percent Convertible Senior Notes
Fair value of outstanding notes	$	215,320	$	223,900
Principal amount of convertible notes outstanding	$	61,247	$	61,247
Unamortized portion of debt discount	$	10,886	$	13,233
Long-term debt	$	50,361	$	48,014
Carrying value of equity component	$	18,714	$	18,714
1 Percent Convertible Senior Notes
Fair value of outstanding notes	$	555,000	$	568,000
Principal amount of convertible notes outstanding	$	500,000	$	500,000
Unamortized portion of debt discount	$	152,786	$	172,514
Long-term debt	$	347,214	$	327,486
Carrying value of equity component	$	174,770	$	174,770

Maturity Schedules

Annual debt and other obligation maturities, including fixed and determinable interest, at December 31, 2015 are as follows (in thousands):

2016	$	15,767
2017		6,744
2018		6,744
2019		6,744
2020		66,304
Thereafter		505,960
Subtotal	$	608,263
Less: current portion		(9,029	)
Less: fixed and determinable interest		(37,655	)
Less: unamortized portion of debt discount		(163,672	)
Plus: Deferred rent		2,006
Total	$	399,913

Future Minimum Payments Under Operating Leases

Annual future minimum payments under operating leases as of December 31, 2015 are as follows (in thousands):

	Operating Leases
2016	$	1,879
2017		1,878
2018		1,597
2019		1,474
2020		1,527
Thereafter		16,125
Total minimum payments	$	24,480

Future Rent Payments for Research and Development Facility Lease Obligation

Annual future rent payments as of December 31, 2015 for our primary research and development facility are as follows (in thousands):

	Future Rent Payments
2016	$	6,550
2017		6,550
2018		6,943
2019		6,943
2020		7,359
Thereafter		91,205
Total minimum payments	$	125,550