Summary of Significant Accounting Policies - Loss Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 4.50% Notes [Member]	Mar. 31, 2014 4.50% Notes [Member]	Dec. 31, 2013 4.50% Notes [Member]	Jun. 30, 2014 7.50% Notes [Member]	Mar. 31, 2014 7.50% Notes [Member]	Dec. 31, 2013 7.50% Notes [Member]	Jun. 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)	16,540	2,559,833	35,603	2,565,607
Numerator: [Abstract]
Basic and diluted loss per share - net loss	$ (2,289)	$ (4,668)	$ (4,214)	$ (9,427)
Denominator: [Abstract]
Basic and diluted weighted average shares outstanding (in shares)	21,940,284	12,993,514	21,935,097	12,824,927
Basic and diluted loss per share (in dollars per share)	$ (0.10)	$ (0.36)	$ (0.19)	$ (0.74)