Shareholders' Equity (Details) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended		0 Months Ended	6 Months Ended			6 Months Ended								6 Months Ended						0 Months Ended	6 Months Ended	0 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jul. 03, 2013 Subsequent events	Jun. 30, 2012 Common Stock	Jun. 30, 2013 Common Stock	Dec. 31, 2012 Common Stock	Jun. 30, 2013 Additional Paid-in Capital	Jun. 30, 2012 Additional Paid-in Capital	Jun. 30, 2013 Accumulated Deficit	Jun. 30, 2012 Accumulated Deficit	Jun. 30, 2013 Treasury Stock	Dec. 31, 2012 Treasury Stock	Jun. 30, 2012 Treasury Stock	Dec. 31, 2011 Treasury Stock	Jun. 30, 2013 Non-controlling Interests	Jun. 30, 2012 Non-controlling Interests	Jun. 30, 2013 Preferred Stock A	Dec. 31, 2012 Preferred Stock A	Jun. 30, 2012 Preferred Stock A	Dec. 31, 2011 Preferred Stock A	Jul. 03, 2013 Preferred Stock A Subsequent events	Jun. 30, 2013 Preferred Stock A Subsequent events	Apr. 30, 2013 Preferred Stock B	Jun. 30, 2013 Preferred Stock B	Dec. 31, 2012 Preferred Stock B
Changes in shareholders' equity
Balance at the beginning of the period				$ 168,605,000	$ 68,560,000		$ 10,000	$ 18,000	$ 18,000	$ 203,996,000	$ 154,552,000	$ (37,664,000)	$ (88,487,000)	$ (196,000)	$ (196,000)	$ (155,000)	$ (155,000)	$ 2,451,000	$ 2,640,000
Balance at the beginning of the period (in shares)							9,958,000	18,072,000	18,072,000											10,000	10,000	10,000	10,000
Net income		8,812,000	(16,589,000)	9,669,000	(22,976,000)							9,492,000	(23,118,000)					177,000	142,000
Cash dividend paid to Series B preferred shareholder				(700,000)						(700,000)
Issuance of common stock					48,270,000		7,000				48,263,000
Issuance of common stock (in shares)	7,923,069						7,923,000
Stock-based compensation				40,000	403,000					40,000	403,000
Balance at the end of the period	94,257,000	177,614,000	94,257,000	177,614,000	94,257,000		17,000	18,000	18,000	203,336,000	203,218,000	(28,172,000)	(111,605,000)	(196,000)	(196,000)	(155,000)	(155,000)	2,628,000	2,782,000
Balance at the end of the period (in shares)							17,881,000	18,072,000	18,072,000											10,000	10,000	10,000	10,000
Preferred stock, shares purchased																										1
Book value of preferred stock (in dollar per share)																									$ 100	$ 0
Cash paid to purchase																										700,000
Preferred stock cancelled and retired (in shares)																										1
Difference in amount between the consideration transferred to the shareholder and the book value of preferred stock																									$ 19,000,000	$ 700,000
Preferred stock, shares outstanding																				10,000	10,000						0	1
Preferred stock converted into common stock (in shares)																								10,000
Common stock issued in exchange for outstanding preferred stock (in shares)						903,825