Summary of Significant Accounting Policies - Loss Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 4.50% Notes [Member]	Dec. 31, 2013 4.50% Notes [Member]	Mar. 31, 2014 7.50% Notes [Member]	Dec. 31, 2013 7.50% 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%	7.50%	7.50%	7.50%	7.50%
Weighted average number of shares cancelled (in shares)	7,870	2,364
Issuance of common stock (in shares)	19,063	6,734
Numerator: [Abstract]
Basic and diluted loss per share - net loss	$ (1,926)	$ (4,759)
Denominator: [Abstract]
Basic and diluted weighted average shares outstanding (in shares)	21,929,852	12,654,466