Annual report pursuant to Section 13 and 15(d)

Variable Interest Entities (New Markets Tax Credit Entities) (Details)

v3.8.0.1
Variable Interest Entities (New Markets Tax Credit Entities) (Details) - Variable Interest Entity, Primary Beneficiary - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Variable Interest Entity [Line Items]    
Tax credit percentage 39.00%  
Restricted cash $ 15.4 $ 0.9
Percentage of recapture 100.00%  
Recapture period 7 years  
Assets $ 165.9 140.9
Liabilities $ 121.2 $ 104.2