v3.3.1.900
Compensation Plans - Schedule of Various Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense $ 3,600 $ 2,900 $ 5,000
Weighted average fair value (usd per share) $ 19,210 $ 16,840  
Restricted Stock Units (RSUs)      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense $ 725 $ 945 1,142
Total fair value at vesting date 809 913 828
Total unrecognized compensation cost for nonvested stock units $ 942 $ 1,462 $ 2,168
Expected years to recognize unearned compensation 1 year 8 months 2 years 8 months 12 days 3 years 7 months 6 days
Stock Options and SSARs      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense $ 50 $ 103 $ 213
Intrinsic value of option exercises on date of exercise 74 226 300
Cash received from the exercise of stock options 126 149 2,040
Stock Plan for Non-Management Directors      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Compensation expense $ 373 $ 329 $ 262
Number of shares issued 16,283,000 23,135,000 16,990,000
Weighted average fair value (usd per share) $ 24.43 $ 19.20 $ 15.40