Borrowings (Schedule Of Structured Financings And Pledged Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	$ 1,541.4	$ 1,925.7
Pledged Assets	4,110.6	4,148.3
Total Return Swap (TRS)
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	493.0
Pledged Assets	818.6
Commercial Banking
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	1,541.4	1,809.9
Pledged Assets	4,110.6	3,935.7
Non-Strategic Portfolios
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	0.0	115.8
Pledged Assets	0.0	212.6
Disposal Group, Held-for-sale, Not Discontinued Operations | Sale of Nacco
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured debt related to sale of business	250.3
Pledged assets related to sale of business	421.9
Business Capital | Commercial Banking
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	768.8	949.8
Pledged Assets	2,838.6	2,608.0
Rail | Commercial Banking
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	772.6	860.1
Pledged Assets	1,272.0	1,327.5
Commercial Finance | Commercial Banking
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Secured Borrowing	0.0	0.0
Pledged Assets	$ 0.0	$ 0.2