Annual report pursuant to Section 13 and 15(d)

Equity Transactions (Details)

v3.8.0.1
Equity Transactions (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 19, 2016
Sep. 06, 2016
May 26, 2016
Apr. 25, 2016
Mar. 09, 2016
Feb. 04, 2016
Nov. 16, 2015
Mar. 13, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Class of Stock [Line Items]                      
Preferred stock dividend                 $ 7,295 $ 7,295 $ 7,895
Proceeds from issuance of common stock                 $ 0 $ 1,357,577 $ 175,459
Series A Preferred Stock                      
Class of Stock [Line Items]                      
Dividend rate, percentage                 10.00%    
Preferred stock, liquidation preference (in dollars per share)                 $ 50.00 $ 50.00  
Preferred stock, dividend rate                 5.00    
Value of a share of common stock                 $ 12.15    
Preferred stock shares issued upon conversion                 4.1    
Conversion of stock, shares converted           120,000          
Preferred stock, shares issued                 1,458,948    
Preferred stock, shares outstanding                 1,458,948 1,458,948  
Common Stock                      
Class of Stock [Line Items]                      
Conversion of stock, shares issued           719,000          
Shares of common stock issued in public offering 40,000,000 29,900,000   25,300,000 15,250,000   12,000,000 9,000,000      
Sales price of shares issued             $ 8.40 $ 6.55      
Proceeds from issuance of common stock $ 634,934 $ 421,864   $ 205,869 $ 94,948   $ 109,864 $ 65,595      
Common Stock | Over-Allotment Option                      
Class of Stock [Line Items]                      
Shares of common stock issued in public offering             1,800,000 1,350,000      
Common Stock | Big Star Transaction                      
Class of Stock [Line Items]                      
Shares of common stock issued in acquisition     9,333,333                
Sales price of shares issued     $ 11.74