XML 44 R31.htm IDEA: XBRL DOCUMENT v3.7.0.1
Capital Stock - Narrative (Details)
 3 Months Ended
Mar. 31, 2017
USD ($)
$ / shares
shares
May 05, 2017
USD ($)
Dec. 31, 2016
$ / shares
shares
Nov. 30, 2015
USD ($)
Class of Stock [Line Items]        
Common stock, shares authorized (up to) | shares 400,000,000   400,000,000  
Common stock, par value (in dollars per share) | $ / shares $ 0.01   $ 0.01  
Preferred stock, shares authorized (up to) | shares 10,000,000   10,000,000  
Preferred stock, par value (in dollars per share) | $ / shares $ 0.01   $ 0.01  
Preferred stock, shares outstanding | shares 0   0  
Common stock partnership units option redemption ratio 1      
Common Stock        
Class of Stock [Line Items]        
Aggregate offering price (up to) | $ $ 200,000,000      
Remaining amount under ATM program | $ $ 128,300,000      
Value amount of shares authorized to be repurchased (up to) | $       $ 150,000,000
Unaffiliated Third Parties        
Class of Stock [Line Items]        
Operating partnerships units held (in shares) | shares 0   0  
Subsequent Event        
Class of Stock [Line Items]        
Remaining capacity | $   $ 143,500,000