Loss Per Common Share (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Undeclared preferred dividends     $ 24,807  
Common shares        
Shares with anti-dilutive effect, not included in calculation of earnings per share 7,014,824 5,136,726 6,633,967 5,163,035
Convertible Preferred Stock        
Shares with anti-dilutive effect, not included in calculation of earnings per share 3,499,000 5,625,370 3,499,000 5,625,370