Income Taxes - Schedule of Common Stock Dividends Characterized for Tax (Details) - Income Tax - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dividends Per Share [Line Items]      
Common stock dividends paid (in dollars per share) $ 2.50 $ 2.50 $ 8.01
Common Shares      
Dividends Per Share [Line Items]      
Ordinary income (in dollars per share) 1.80 1.94 2.63
Return of capital (in dollars per share) $ 0.70 0.05 0.22
Capital gain (in dollars per share)   $ 0.51 $ 5.16