v3.8.0.1
Stockholders' Equity - Narrative - Restricted Stock (Details)
12 Months Ended
Dec. 31, 2017
RSU [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 4 years
PSU [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting period 3 years
PSU [Member] | Maximum [Member]  
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Vesting percent 150.00%