Convertible Senior Secured Notes (Details) (USD $)	12 Months Ended			12 Months Ended					0 Months Ended	2 Months Ended	12 Months Ended		12 Months Ended		12 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2013 Occurrence of fundamental change	Dec. 31, 2013 Occurrence of fundamental change Minimum	Dec. 31, 2013 Occurrence of fundamental change Maximum	Dec. 31, 2013 Occurrence of make-whole fundamental change	Dec. 31, 2013 Company redeems Notes on or after May 1, 2017 item	May 03, 2013 7.50% Convertible Senior Secured Notes due 2019	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019 Company has not received stockholder approval	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019 Company obtains stockholder approval prior to day before November 1, 2018 item	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019 Company calls Notes for redemption prior to day before redemption date and Note holder converts on or after November 1, 2018	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019 On or after November 1, 2013, Company makes interest make-whole payments item	Dec. 31, 2013 7.50% Convertible Senior Secured Notes due 2019 On or after November 1, 2013, Company makes interest make-whole payments Maximum	May 03, 2013 Term loans under secured credit facility	May 31, 2013 Term loans under secured credit facility	Dec. 31, 2013 Term loans under secured credit facility
Notes payable
Gross proceeds		$ 30,000,000									$ 90,000,000
Fixed interest rate (as a percent)	7.50%								7.50%	7.50%	7.50%
Amount of underwriters' fee									3,000,000
Offering expenses									3,500,000
Net proceeds from issuance of debt	90,000,000								86,500,000
Repayment of debt																	19,600,000	19,600,000
Minimum percentage of debt holder's consent require to transfer property collateral for notes									66.67%
Principal amount used for debt instrument conversion ratio				1,000						1,000	1,000	1,000	1,000	1,000	1,000
Threshold trading days (whether or not consecutive)								20					20		20
Consecutive trading day period								30 days					30 days		30 days
Number of trading days prior to a conversion date within which threshold trading days should complete													5		5
Threshold trading days period prior to a conversion date during which principal amount of notes for such trading day was less than 98% of the product of the last reported sale price of common stock													5
Consecutive trading day period prior to a conversion date during which principal amount of notes for such trading day was less than 98% of the product of the last reported sale price of common stock													5 days
Maximum ratio of trading price for each day in measurement period to last reported sales price of Company's stock on each day of measurement period													98.00%
Conversion rate for the Notes (in shares)											188.7059					221.7294
Conversion price, per share of Common Stock										$ 5.30	$ 5.30
Discount rate (as a percent)															2.00%
Stock value as percentage of simple average of the daily volume-weighted average price if the company elects to pay an interest make-whole payment in common stock															95.00%
Number of trading days ending on and including the trading day immediately preceding the conversion date use to determine daily volume weighted average price															10
Required notice period for notification of fundamental change				1 day			50 days
Period from notice date within which note holders can exercise their right to exchange the notes					20 days	35 days
Redemption price (as a percent)				100.00%				100.00%
Threshold percentage of common stock price to determine eligibility of conversion								140.00%
Details of Notes reflected in balance sheet
Gross proceeds		30,000,000									90,000,000
Initial value of interest make-whole derivative reported as debt discount											(9,270,000)
Conversion option reported as debt discount and APIC									900,000		(22,336,000)
Conversion of debt to equity - principal										40,500,000	(40,492,000)
Conversion of debt to equity - debt discount										13,833,000	13,833,000
Amortization of debt discount											2,658,000
Carrying value	34,393,000									34,393,000	34,393,000
Unamortized debt issuance costs									2,600,000	1,200,000	1,200,000
Deferred financing costs, current	229,000		144,000							200,000	200,000
Deferred financing costs, long-term	1,005,000		89,000							1,000,000	1,000,000
Shares of common stock issued in conversion of Notes										7,641,060	7,600,000
Shares of common stock issued in settlement of the interest make-whole provision										1,337,193	1,300,000
Cash paid in settlement of the interest make-whole provision											1,700,000
Loss on extinguishment of debt	$ 9,550,000										$ 8,400,000								$ 1,200,000