Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Summarize Activity of the Net Product Revenue Allowance and Reserve Categories

The following table summarizes activity in each of the net product revenue allowance and reserve categories described above for the years ended December 31, 2015 and 2014 (in thousands):


	Trade Allowances			Rebates, Chargebacks and Discounts			Product Returns			Other Incentives			Total
Balance as of January 1, 2014	$	1,071		$	1,137		$	72		$	189		$	2,469
Provision related to current period sales		8,157			12,753			397			11,153			32,460
Provision related to prior period sales		(29	)		(80	)		12			(31	)		(128	)
Credits/payments made for current period sales		(5,950	)		(9,143	)		—			(10,338	)		(25,431	)
Credits/payments made for prior period sales		(1,042	)		(1,057	)		—			(181	)		(2,280	)

Balance as of December 31, 2014	$	2,207		$	3,610		$	481		$	792		$	7,090
Provision related to current period sales		14,986			32,591			342			8,310			56,229
Provision related to prior period sales		(174	)		(70	)		(205	)		—			(449	)
Credits/payments made for current period sales		(10,690	)		(22,710	)		—			(7,226	)		(40,626	)
Credits/payments made for prior period sales		(2,033	)		(3,540	)		(83	)		(792	)		(6,448	)

Balance as of December 31, 2015	$	4,296		$	9,881		$	535		$	1,084		$	15,796

Summarizes the Impact of Accounts Receivable Reserves on Gross Trade Accounts Receivable

The following table summarizes the impact of accounts receivable reserves on the gross trade accounts receivable balances as of December 31, 2015 and 2014 (in thousands):


	December 31, 2015			December 31, 2014
Gross trade accounts receivable	$	18,270		$	10,215
Trade allowances		(4,296	)		(2,207	)
Chargebacks		(148	)		(166	)

Accounts receivable, net	$	13,826		$	7,842

Estimated Useful Lives

The estimated useful lives, by asset classification, are as follows:


Asset Classification		Useful Lives
Computer equipment and software		3 - 5 years
Furniture and fixtures		5 years
Leasehold improvements		Lesser of useful life or lease term

Net Loss and the Number of Shares Used to Compute Basic and Diluted Net Loss per Share

The calculation of net loss and the number of shares used to compute basic and diluted net loss per share for the years ended December 31, 2015, 2014 and 2013 are as follows:


In thousands	2015			2014			2013
Net loss	$	(115,204	)	$	(56,364	)	$	(166,227	)
Preferred stock purchase option (see Note 10)		(868	)		—			—
Preferred stock beneficial conversion features (see Note 10)		(32,987	)		—			—

Net loss applicable to common shareholders—basic		(149,059	)		(56,364	)		(166,227	)
Gain on warrant derivative liability		—			(6,775	)		(47,936	)

Net loss—diluted		(149,059	)		(63,139	)		(214,163	)
Net loss per share—basic	$	(0.83	)	$	(0.32	)	$	(1.03	)
Weighted average shares outstanding—basic		180,654			173,719			161,022
Effect of dilutive warrants		—			105			6,048

Weighted average shares outstanding—diluted		180,654			173,824			167,070
Net loss per share—diluted	$	(0.83	)	$	(0.36	)	$	(1.28	)

Anti-Dilutive Securities Not Included in the Computation of Net Loss or Earnings per Share

For the years ended December 31, 2015, 2014 and 2013, the following potentially dilutive securities were not included in the computation of net loss per share because the effect would be anti-dilutive:


In thousands	2015		2014		2013
Stock options		17,818		10,670		9,330
Restricted stock and restricted stock units		10,887		2,256		196
Warrants		—		—		1,702
Exchangeable senior notes (if converted)		59,407		49,215		17,021
Preferred stock (if converted)		32,818		—		—

Assets and Liability Measured at Fair Value on a Recurring Basis

The following tables present information about the Company’s assets and liabilities as of December 31, 2015 and 2014 that are measured at fair value on a recurring basis and indicate the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value:


	December 31, 2015
*In thousands*	Total		Level 1		Level 2		Level 3
Asset:
Cash equivalents—money markets	$	14,184	$	14,184	$	—	$	—

Liabilities:
Long-term debt derivative liabilities	$	8,170	$	—	$	—	$	8,170


	December 31, 2014
*In thousands*	Total		Level 1		Level 2		Level 3
Asset:
Cash equivalents—money markets	$	65,156	$	65,156	$	—	$	—

Liabilities:
Warrant derivative liability	$	119	$	—	$	—	$	119
Long-term debt derivative liabilities	$	7,400	$	—	$	—	$	7,400

Carrying Amounts and Estimated Fair Values of Debt Instruments

The carrying amounts and the estimated fair values of debt instruments as of December 31, 2015 and 2014 are as follows:


	December 31, 2015				December 31, 2014
In thousands	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
Long-term debt—December 2012 financing	$	91,512	$	87,700	$	89,617	$	81,000
2012 Notes		15,107		13,637		31,266		25,689
2014 Notes		96,364		108,034		90,580		75,533
2015 Notes		27,134		28,448		—		—

Change in Fair Value of Derivative Liabilities

The change in the fair value of derivative liabilities for the years ended December 31, 2015 and 2014 is as follows (in thousands):


	October 2009 Warrants			Long-Term Debt Derivative Liabilities			Preferred Stock Purchase Option			Total
Balance as of January 1, 2014	$	6,894		$	11,100		$	—		$	17,994
Record initial fair value of derivative liability on 2014 Notes		—			3,500			—			3,500
Gain on change in fair value of derivative liabilities		(6,272	)		(7,200	)		—			(13,472	)
Compensation income for change in fair value of warrants issued to former employees		(503	)		—			—			(503	)

Balance as of December 31, 2014	$	119		$	7,400		$	—		$	7,519
Record initial fair value of derivative liability		—			500			868			1,368
(Gain) loss on change in fair value of derivative liabilities		(110	)		270			946			1,106
Compensation income for change in fair value of warrants issued to former employees		(9	)		—			—			(9	)
Transfer derivative liability to equity		—			—			(1,814	)		(1,814	)

Balance as of December 31, 2015	$	—		$	8,170		$	—		$	8,170