Equity - Distributions (Details) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Distributions Per Share      
Total distributions paid (usd per share) $ 0.6500 $ 0.6500 $ 0.6500
Ordinary income      
Distributions Per Share      
Total distributions paid (usd per share) 0.1994 0.3220 0.3528
Capital gain      
Distributions Per Share      
Total distributions paid (usd per share) 0.3103 0.0000 0.0000
Return of capital      
Distributions Per Share      
Total distributions paid (usd per share) $ 0.1403 $ 0.3280 $ 0.2972