Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Narrative (Details)

v3.10.0.1
Employee Benefit Plans - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Requisite service years 1 year    
Requisite service period 1 year    
Employer contribution amount $ 0.1 $ 0.1 $ 0.1
Reclassification adjustment from AOCI, net of tax 0.1 0.1 0.1
Reclassification adjustment from AOCI, tax 0.1 $ 0.1 $ 0.1
Reclassification adjustment from AOCI over the next fiscal year $ 0.1    
Expected return on plan assets 7.00% 7.00% 7.00%
Inflation Rate      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Expected return on plan assets 2.50%    
Fixed Income Securities      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Expected return on plan assets 2.50%    
Allocation of expected return on plan assets 66.66667%    
Fixed Income Securities | Minimum      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Target allocation percentage 30.00%    
Fixed Income Securities | Maximum      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Target allocation percentage 80.00%    
Equity securities      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Expected return on plan assets 8.50%    
Allocation of expected return on plan assets 33.33333%    
Equity securities | Minimum      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Target allocation percentage 20.00%    
Equity securities | Maximum      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Target allocation percentage 60.00%