Quarterly report pursuant to Section 13 or 15(d)

Variable Interest Entities (Details)

v3.7.0.1
Variable Interest Entities (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 21, 2017
Dec. 11, 2012
Oct. 03, 2012
Aug. 30, 2011
Mar. 31, 2017
Dec. 31, 2016
Variable Interest Entity [Line Items]            
Restricted cash         $ 4.6  
Primary Beneficiary [Member]            
Variable Interest Entity [Line Items]            
Tax credit percentage         39.00%  
Percentage of recapture         100.00%  
Recapture period         7 years  
Assets         $ 150.9 $ 140.9
Liabilities         $ 110.9 $ 104.2
Primary Beneficiary [Member] | NMTC 1 [Member]            
Variable Interest Entity [Line Items]            
Loans to VIE       $ 58.3    
Interest rate percentage       1.00%    
Primary Beneficiary [Member] | NMTC 1 [Member] | Minimum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage       1.00%    
Primary Beneficiary [Member] | NMTC 1 [Member] | Maximum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage       3.96%    
Primary Beneficiary [Member] | NMTC 1 [Member] | US Bancorp [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity       $ 22.4    
Primary Beneficiary [Member] | NMTC 1 [Member] | Community Development Entities [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity       $ 76.8    
Primary Beneficiary [Member] | NMTC 2 [Member]            
Variable Interest Entity [Line Items]            
Loans to VIE     $ 37.7      
Interest rate percentage     1.00%      
Primary Beneficiary [Member] | NMTC 2 [Member] | Minimum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage     0.7099%      
Primary Beneficiary [Member] | NMTC 2 [Member] | Maximum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage     0.7693%      
Primary Beneficiary [Member] | NMTC 2 [Member] | US Bancorp [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity     $ 17.5      
Primary Beneficiary [Member] | NMTC 2 [Member] | Community Development Entities [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity     $ 55.2      
Primary Beneficiary [Member] | NMTC 3 [Member]            
Variable Interest Entity [Line Items]            
Loans to VIE   $ 8.2        
Interest rate percentage   1.00%        
Primary Beneficiary [Member] | NMTC 3 [Member] | Maximum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage   1.35%        
Primary Beneficiary [Member] | NMTC 3 [Member] | US Bancorp [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity   $ 3.8        
Primary Beneficiary [Member] | NMTC 3 [Member] | Community Development Entities [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity   $ 12.0        
Primary Beneficiary [Member] | NMTC 4 [Member]            
Variable Interest Entity [Line Items]            
Loans to VIE $ 6.7          
Interest rate percentage 1.00%          
Primary Beneficiary [Member] | NMTC 4 [Member] | Maximum [Member]            
Variable Interest Entity [Line Items]            
Interest rate percentage 0.7337%          
Primary Beneficiary [Member] | NMTC 4 [Member] | US Bancorp [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity $ 3.3          
Primary Beneficiary [Member] | NMTC 4 [Member] | Community Development Entities [Member]            
Variable Interest Entity [Line Items]            
Amount to other entity 9.8          
Placement fees $ 0.2