Stock Compensation Plans (Restricted Stock Unit Vesting) (Details) - Restricted Stock Units (RSUs) [Member]	Dec. 31, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting in future period	944,500
2018 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting in future period	178,250
2019 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting in future period	373,750
2020 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting in future period	231,250
2021 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting in future period	161,250