Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2013

Information about Fair Value of Company's Marketable Securities

The following table presents information about the Company’s marketable securities as of December 31, 2012 and indicates the fair value hierarchy of the valuation techniques the Company utilized to determine such fair value:

	December 31, 2012
In thousands	Total		Level 1		Level 2		Level 3
Marketable securities	$	45,035	$	—	$	45,035	$	—

Changes in Fair Value of Warrant Liability

The changes in the fair value of the warrant liability for the years ended December 31, 2012 and 2011 were as follows:

In thousands	2012			2011
Balance, beginning of the year:	$	58,639		$	28,815
Issuance of warrants		—			—
Revaluation of warrants		15,924			46,715
Exercise of warrants		(74,563	)		(16,891	)
Balance, end of year	$	—		$	58,639