Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events (Details)

v3.5.0.2
Subsequent Events (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 9 Months Ended
Oct. 26, 2016
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Oct. 01, 2016
Jan. 27, 2015
Subsequent Event [Line Items]              
Dividends declared per share (in dollars per share)   $ 0.75 $ 0.675 $ 2.25 $ 2    
Common Stock [Member] | Subsequent Event [Member]              
Subsequent Event [Line Items]              
Dividends declared per share (in dollars per share) $ 0.750            
Series A Cumulative Redeemable Preferred Stock [Member] | Depositary Shares [Member] | Subsequent Event [Member]              
Subsequent Event [Line Items]              
Depositary stock, dividends declared per share (in dollars per share) $ 0.4609375            
Series A Cumulative Redeemable Preferred Stock [Member] | Preferred Stock [Member]              
Subsequent Event [Line Items]              
Coupon rate percentage   7.375%   7.375%     7.375%
SWD Enterprises [Member] | Subsequent Event [Member]              
Subsequent Event [Line Items]              
Reduction in interest rate           10.00%  
SWD Enterprises [Member] | REIT Loan [Member] | Subsequent Event [Member]              
Subsequent Event [Line Items]              
Financing receivable           $ 4.0  
SWD Enterprises [Member] | TRS Loan [Member] | Subsequent Event [Member]              
Subsequent Event [Line Items]              
Financing receivable           $ 1.0