Consolidated Statements of Stockholders' Equity - USD ($)
$ in Thousands
Total
Series A Preferred Stock
Preferred Stock Including Additional Paid in Capital [Member]
Preferred Stock Including Additional Paid in Capital [Member]
Series A Preferred Stock
Common Stock
Capital in Excess of Par Value
Accumulated Deficit
AOCL
Preferred shares outstanding, beginning of period at Dec. 31, 2014     0          
Common shares outstanding, beginning of period at Dec. 31, 2014         411,350,440      
Balances, beginning of period at Dec. 31, 2014 $ 3,311,662   $ 0   $ 4,113 $ 4,361,320 $ (1,052,688) $ (1,083)
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Net income 93,212           93,212  
Other comprehensive income 55             55
Dividends declared on common stock (298,531)           (298,531)  
Tax withholdings related to net stock settlements (in shares)         (426,158)      
Tax withholdings related to net stock settlements (4,272)       $ (4)   (4,268)  
Issuance of shares of common stock, net (in shares)         29,610,100      
Issuance of shares of common stock, net 347,211       $ 296 346,915    
Exercise of stock options (in shares)         5,000      
Exercise of stock options 46         46    
Stock-based compensation, net (in shares)         1,280,582      
Stock-based compensation, net 12,491       $ 13 13,042 (564)  
Net income attributable to common stockholders/ after preferred distributions 93,212              
Preferred shares outstanding, end of period at Dec. 31, 2015     0          
Common shares outstanding, end of period at Dec. 31, 2015         441,819,964      
Balances, end of period at Dec. 31, 2015 3,461,874   $ 0   $ 4,418 4,721,323 (1,262,839) (1,028)
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Net income 97,446           97,446  
Other comprehensive income 1,028             1,028
Dividends declared on common stock (333,180)           (333,180)  
Tax withholdings related to net stock settlements (in shares)         (72,835)      
Tax withholdings related to net stock settlements (753)       $ (1)   (752)  
Issuance of shares of common stock, net (in shares)         40,835,360      
Issuance of shares of common stock, net 446,613       $ 408 446,205    
Stock-based compensation, net (in shares)         1,041,631      
Stock-based compensation, net 9,080       $ 11 9,558 (489)  
Net income attributable to common stockholders/ after preferred distributions $ 97,446              
Preferred shares outstanding, end of period at Dec. 31, 2016 0   0          
Common shares outstanding, end of period at Dec. 31, 2016 483,624,120       483,624,120      
Balances, end of period at Dec. 31, 2016 $ 3,682,108   $ 0   $ 4,836 5,177,086 (1,499,814) 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]                
Net income 77,148           77,148  
Dividends declared on common stock (332,402)           (332,402)  
Tax withholdings related to net stock settlements (in shares)         (440,312)      
Tax withholdings related to net stock settlements (3,542)       $ (4)   (3,538)  
Repurchase of common shares (in shares)         (35,839,965)      
Repurchase of common shares (283,089)       $ (358)   (282,731)  
Issuance of shares of common stock, net (in shares)       6,900,000        
Issuance of shares of common stock, net   $ 166,193   $ 166,193        
Stock-based compensation, net (in shares)         1,524,426      
Stock-based compensation, net 15,723       $ 15 16,545 (837)  
Dividends declared on preferred stock (2,530)           (2,530)  
Net income attributable to common stockholders/ after preferred distributions $ 74,618           74,618  
Preferred shares outstanding, end of period at Dec. 31, 2017 6,900,000   6,900,000          
Common shares outstanding, end of period at Dec. 31, 2017 448,868,269       448,868,269      
Balances, end of period at Dec. 31, 2017 $ 3,319,609   $ 166,193   $ 4,489 $ 5,193,631 $ (2,044,704) $ 0