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Goodwill And Intangible Assets (Narrative) (Details) $ in Millions			3 Months Ended
	Jan. 01, 2020 USD ($)	Aug. 05, 2015 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 146.8	$ 369.9
Intangible assets acquired			102.6
Goodwill impairment			344.7
Accumulated amortization			124.8	116.3
Projected amortization for 2021			33.7
Projected amortization for 2022			32.2
Projected amortization for 2023			19.5
Projected amortization for 2024			13.4
Projected amortization for 2025			13.3
Core deposit intangibles
Business Acquisition [Line Items]
Intangible assets acquired			96.1
Accumulated amortization			86.6	79.7
Rail
Business Acquisition [Line Items]
Goodwill			25.2
Commercial Finance
Business Acquisition [Line Items]
Goodwill impairment			159.9
Real Estate Finance
Business Acquisition [Line Items]
Goodwill impairment			141.6
Consumer Banking
Business Acquisition [Line Items]
Goodwill impairment			$ 43.2
Maximum \| Core deposit intangibles
Business Acquisition [Line Items]
Estimated useful life			7 years
Long-Term Revenue Growth Rate \| Reporting Units
Business Acquisition [Line Items]
Fair value input rate			3
Discount Rate \| Reporting Units \| Minimum
Business Acquisition [Line Items]
Fair value input rate			10.25
Discount Rate \| Reporting Units \| Maximum
Business Acquisition [Line Items]
Fair value input rate			11.25
Control Premium \| Reporting Units
Business Acquisition [Line Items]
Fair value input rate			40
MOB
Business Acquisition [Line Items]
Goodwill	$ 121.6
Intangible assets acquired	102.6
MOB \| Core deposit intangibles
Business Acquisition [Line Items]
Intangible assets acquired	$ 96.1
Estimated useful life	10 years
Customer Relationships and Trade Names \| OneWest Bank
Business Acquisition [Line Items]
Intangible assets acquired		$ 102.6
Commercial Banking
Business Acquisition [Line Items]
Goodwill			$ 141.6	326.7
Goodwill impairment			301.5
Commercial Banking \| MOB
Business Acquisition [Line Items]
Goodwill	$ 116.4
Consumer Banking
Business Acquisition [Line Items]
Goodwill			5.2	$ 43.2
Goodwill impairment			$ 43.2
Consumer Banking \| MOB
Business Acquisition [Line Items]
Goodwill	$ 5.2