ACCOUNTING POLICIES - The Company and Business Combinations and Divestitures Narrative (Details) $ in Millions		9 Months Ended
	Jun. 29, 2018 USD ($) shares	Sep. 30, 2018 USD ($) ATM branch	Jul. 01, 2018 USD ($)	Apr. 01, 2018 USD ($)
Business Acquisition [Line Items]
Number of branches | branch		140
Number of ATM's | ATM		190
Carrying value of assets managed			$ 400.0
Loans sold	$ 206.3
DHFB
Business Acquisition [Line Items]
Carrying value of assets managed				$ 600.0
Outfitter Advisors Ltd.
Business Acquisition [Line Items]
Carrying value of assets managed			$ 400.0
Shore Premier
Business Acquisition [Line Items]
Assets and liabilities sold	383.9
Cash received	$ 375.0
Amount of shares received in transaction | shares	1,250,000
Fair value of purchasing company's stock		$ 27.4
Gain disposal of loans, net	$ 15.8
Xenith
Business Acquisition [Line Items]
Number of branches | branch		7