Annual report pursuant to Section 13 and 15(d)

Employee Benefits (Details)

v3.6.0.2
Employee Benefits (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
401(k)      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Employer matching contribution percent 100.00%    
Employer matching percent 6.00%    
Employer contributions $ 4,600 $ 4,733 $ 4,556
GPPP      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Employer matching contribution percent 100.00%    
Employer matching percent 6.00%    
Employer contributions $ 202    
RRSP      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Employer matching contribution percent 100.00%    
Employer matching percent 6.00%    
Employer contributions $ 307 $ 411 $ 475