XML 40 R28.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock Repurchase Program (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2017
Jun. 30, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Feb. 28, 2017
Feb. 29, 2016
Jan. 31, 2014
January 2014 Plan                
Class of Stock [Line Items]                
Number of shares authorized to be repurchased (up to) (in shares)               500,000
Remaining number of shares authorized to be repurchased (in shares)       56,000        
January 2014 Plan | Treasury Stock                
Class of Stock [Line Items]                
Shares repurchase and retired during period (in shares)       212,000 261,000      
Stock repurchased during period, value       $ 1.7 $ 5.9      
February 2016 Plan                
Class of Stock [Line Items]                
Number of shares authorized to be repurchased (up to) (in shares)             1,000,000  
Remaining number of shares authorized to be repurchased (in shares)     56,000          
February 2016 Plan | Treasury Stock                
Class of Stock [Line Items]                
Shares repurchase and retired during period (in shares)     1,056,000          
Stock repurchased during period, value     $ 9.5          
January 2014 and February 2016 Plan                
Class of Stock [Line Items]                
Remaining number of shares authorized to be repurchased (in shares)     0          
February 2017 Plan                
Class of Stock [Line Items]                
Number of shares authorized to be repurchased (up to) (in shares)           1,000,000    
Remaining number of shares authorized to be repurchased (in shares) 291,000 291,000            
February 2017 Plan | Treasury Stock                
Class of Stock [Line Items]                
Shares repurchase and retired during period (in shares) 493,912 708,992            
Stock repurchased during period, value $ 5.0 $ 7.0