Summary of Significant Accounting Policies - Loss Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 4.50% Notes [Member]	Mar. 31, 2014 4.50% Notes [Member]	Dec. 31, 2013 4.50% Notes [Member]	Sep. 30, 2014 7.50% Notes [Member]	Mar. 31, 2014 7.50% Notes [Member]	Dec. 31, 2013 7.50% Notes [Member]	Sep. 30, 2014 7.5% Senior Exchange Convertible Notes [Member]	Mar. 31, 2014 7.5% Senior Exchange Convertible Notes [Member]	Dec. 31, 2013 7.5% Senior Exchange Convertible Notes [Member]
Debt Instrument [Line Items]
Stated interest rate (percent)					4.50%	4.50%	4.50%	7.50%	7.50%	7.50%	7.50%	7.50%	7.50%
Weighted average number of shares cancelled (in shares)	0	0	7,870	2,364
Issuance of common stock (in shares)	0	6,676,371	35,603	9,241,978
Numerator: [Abstract]
Basic and diluted loss per share - net loss	$ 678	$ (1,877)	$ (3,537)	$ (11,301)
Deemed dividend related to beneficial conversion feature of convertible preferred stock (Note 1)	0	(11,894)	0	(11,894)
Income (loss) attributable to common stockholders	$ 678	$ (13,771)	$ (3,537)	$ (23,195)
Denominator: [Abstract]
Basic weighted average shares outstanding (in shares)	21,953,484	16,097,335	21,941,293	13,927,716
Diluted weighted average number of shares outstanding (in shares)	22,071,236	16,097,335	21,941,293	13,927,716
Basic income (loss) per share (in dollars per share)	$ 0.03	$ (0.86)	$ (0.16)	$ (1.67)
Diluted income (loss) per share (in dollars per share)	$ 0.03	$ (0.86)	$ (0.16)	$ (1.67)