XML 102 R88.htm IDEA: XBRL DOCUMENT v3.8.0.1
Capital Stock and Share Based Compensation Plans - Cash proceeds (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash received upon exercise $ 1,461 $ 4,641 $ 7,249
Stock Options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Cash received upon exercise 1,461 4,641 7,249
Intrinsic value (market value on date of exercise less exercise price) 3,919 4,888 10,801
Tax benefits realized [1] $ 1,497 $ 1,877 $ 4,101
[1] (1) Benefits for 2015 were not recognized under prior accounting guidance until realized. In 2017 and 2016, upon adoption of new accounting guidance, they are realized when generated.