Long-term Incentive Plan (Schedule of compensation expense related to stock awards) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
RSUs Redeemable in Stocks      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation expense $ 640 $ 605 $ 702
RSUs Redeemable in Cash      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation expense 580 (349) 1,117
RSUs      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]      
Share-based compensation expense $ 1,220 $ 256 $ 1,819