Quarterly report pursuant to Section 13 or 15(d)

Variable Interest Entities (Summary of Key Terms of NMTC Transactions) (Details)

v3.10.0.1
Variable Interest Entities (Summary of Key Terms of NMTC Transactions) (Details) - Primary Beneficiary
$ in Millions
6 Months Ended
Jun. 30, 2018
USD ($)
NMTC 1  
Variable Interest Entity [Line Items]  
Loans to VIE $ 58.3
Interest rate percentage 1.00%
NMTC 1 | Minimum  
Variable Interest Entity [Line Items]  
Interest rate percentage 1.00%
NMTC 1 | Maximum  
Variable Interest Entity [Line Items]  
Interest rate percentage 3.96%
NMTC 1 | US Bancorp  
Variable Interest Entity [Line Items]  
Amount to other entity $ 22.4
NMTC 1 | Community Development Entities  
Variable Interest Entity [Line Items]  
Amount to other entity 76.8
NMTC 2  
Variable Interest Entity [Line Items]  
Loans to VIE $ 37.7
Interest rate percentage 1.00%
NMTC 2 | Minimum  
Variable Interest Entity [Line Items]  
Interest rate percentage 0.71%
NMTC 2 | Maximum  
Variable Interest Entity [Line Items]  
Interest rate percentage 0.77%
NMTC 2 | US Bancorp  
Variable Interest Entity [Line Items]  
Amount to other entity $ 17.5
NMTC 2 | Community Development Entities  
Variable Interest Entity [Line Items]  
Amount to other entity 52.0
NMTC 3  
Variable Interest Entity [Line Items]  
Loans to VIE $ 8.2
Interest rate percentage 1.00%
NMTC 3 | US Bancorp  
Variable Interest Entity [Line Items]  
Amount to other entity $ 3.8
NMTC 3 | Community Development Entities  
Variable Interest Entity [Line Items]  
Interest rate percentage 1.35%
Amount to other entity $ 12.0
NMTC 4  
Variable Interest Entity [Line Items]  
Loans to VIE $ 6.7
Interest rate percentage 1.00%
NMTC 4 | US Bancorp  
Variable Interest Entity [Line Items]  
Amount to other entity $ 3.3
NMTC 4 | Community Development Entities  
Variable Interest Entity [Line Items]  
Interest rate percentage 0.73%
Amount to other entity $ 9.8
NMTC 5  
Variable Interest Entity [Line Items]  
Loans to VIE $ 10.4
Interest rate percentage 1.00%
NMTC 5 | Minimum  
Variable Interest Entity [Line Items]  
Interest rate percentage 0.67%
NMTC 5 | Maximum  
Variable Interest Entity [Line Items]  
Interest rate percentage 1.24%
NMTC 5 | US Bancorp  
Variable Interest Entity [Line Items]  
Amount to other entity $ 5.1
NMTC 5 | Community Development Entities  
Variable Interest Entity [Line Items]  
Amount to other entity $ 14.7