Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Summarizes 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, 2016 and 2015:

In thousands	Trade Allowances			Rebates, Chargebacks and Discounts			Product Returns			Other Incentives			Total
Balance as of January 1, 2015	$	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
Provision related to current period sales		22,952			69,370			583			11,696			104,601
Provision related to prior period sales		(87	)		(450	)		—			—			(537	)
Credits/payments made for current period sales		(19,213	)		(48,719	)		—			(9,815	)		(77,747	)
Credits/payments made for prior period sales		(4,205	)		(9,167	)		(259	)		(1,284	)		(14,915	)
Balance as of December 31, 2016	$	3,743		$	20,915		$	859		$	1,681		$	27,198

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, 2016 and 2015:

In thousands	December 31, 2016			December 31, 2015
Gross trade accounts receivable	$	24,127		$	18,270
Trade allowances		(3,743	)		(4,296	)
Chargebacks		(387	)		(148	)
Allowance for doubtful accounts		(12	)		—
Accounts receivable, net	$	19,985		$	13,826

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, 2016, 2015 and 2014 are as follows:

In thousands	2016			2015			2014
Net loss	$	(86,350	)	$	(115,204	)	$	(56,364	)
Preferred stock purchase option (see Note 10—Equity)		—			(868	)		—
Preferred stock beneficial conversion features (see Note 10—Equity)		—			(32,987	)		—
Net loss applicable to common shareholders—basic		(86,350	)		(149,059	)		(56,364	)
Gain on warrant derivative liability		—			—			(6,775	)
Net loss—diluted		(86,350	)		(149,059	)		(63,139	)
Net loss per share—basic	$	(0.41	)	$	(0.83	)	$	(0.32	)
Weighted average shares outstanding—basic		211,874			180,654			173,719
Effect of dilutive warrants		—			—			105
Weighted average shares outstanding—diluted		211,874			180,654			173,824
Net loss per share—diluted	$	(0.41	)	$	(0.83	)	$	(0.36	)

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

For the years ended December 31, 2016, 2015 and 2014, 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	2016		2015		2014
Stock options		21,188		17,818		10,670
Restricted stock and restricted stock units		10,143		10,887		2,256
Exchangeable senior notes (if converted)		1,714		59,407		49,215
Preferred stock (if converted)		32,818		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, 2016 and 2015 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, 2016
In thousands	Total		Level 1		Level 2		Level 3
Asset:
Cash equivalents—money markets	$	14,238	$	14,238	$	—	$	—

	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

Carrying Amounts and Estimated Fair Values of Debt Instruments

The carrying amounts of cash, cash equivalents, accounts payable and accrued liabilities approximate fair value because of their short-term nature. The carrying amounts and the estimated fair values of debt instruments as of December 31, 2016 and 2015 are as follows:

	December 31, 2016				December 31, 2015
In thousands	Carrying Value		Estimated Fair  Value		Carrying Value		Estimated Fair  Value
Long-term debt from royalty-bearing instrument	$	85,155	$	90,500	$	91,512	$	87,700
2012 Notes		15,107		15,174		15,107		13,637
2014 Notes		—		—		96,364		108,034
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, 2016 and 2015 is as follows:

In thousands	October 2009 Warrants			Long-Term Debt  Derivative Liabilities			Preferred Stock Purchase Option			Total
Balance as of January 1, 2015	$	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
Gain on change in fair value of derivative liabilities		—			(8,170	)		—			(8,170	)
Balance as of December 31, 2016	$	—		$	—		$	—		$	—