Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans (Narrative) (Details)

v3.6.0.2
Employee Benefit Plans (Narrative) (Details) - USD ($)
$ in Thousands
12 Months Ended
May 12, 2011
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
May 14, 2015
Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Defined contribution plan, employer contribution amount   $ 1,018 $ 999 $ 1,017    
Market-based RSUs [Member] | Vesting Minimum [Member]            
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Share-based compensation arrangement vesting rights, percentage   0.00%        
Market-based RSUs [Member] | Vesting Maximum [Member]            
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Share-based compensation arrangement vesting rights, percentage   200.00%        
Cash-settleable RSU awards [Member] | Vesting Minimum [Member]            
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Share-based compensation arrangement vesting rights, percentage   0.00%        
Cash-settleable RSU awards [Member] | Vesting Maximum [Member]            
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Share-based compensation arrangement vesting rights, percentage   200.00%        
2011 Plan [Member]            
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]            
Number of shares authorized 2,300,000   4,300,000   5,141,000 3,141,000
Increase in number of shares authorized and reserved for issuance 841,000   2,000,000      
Number of shares available for grant   2,270,448