XML 76 R60.htm IDEA: XBRL DOCUMENT v3.6.0.2
Equity - Class of Stock Disclosures - Common Stock and Shelf Registrations (Details) - USD ($)
 1 Months Ended 12 Months Ended
Jan. 29, 2016
Jan. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Equity            
Net proceeds     $ 78,592,000   $ 24,644,000  
Shelf Registration            
Equity            
Maximum offering capacity under shelf registration statement           $ 800,000,000
Automatic shelf registration statement, term (in years) P3Y          
Common Stock            
Equity            
Number of shares repurchased     49,405 26,993    
Common Stock | Subsequent Event            
Equity            
Number of shares repurchased   23,691        
Common Stock | Original Agreement            
Equity            
Maximum offering capacity under shelf registration statement       $ 200,000,000    
Shares common stock sold     1,643,017      
Net proceeds     $ 78,600,000      
Reclassification of accumulated costs to additional paid in capital     463,000      
Common Stock | Equity Distribution Agreements            
Equity            
Maximum offering capacity under shelf registration statement     $ 200,000,000      
Shares common stock sold     0      
Amount available under effective shelf registration statement     $ 200,000,000      
Common Stock | Equity Distribution Agreements | Subsequent Event            
Equity            
Shares common stock sold   312,881        
Net proceeds   $ 14,578,000        
Amount available under effective shelf registration statement   $ 185,162,000