Derivatives and Hedging Activities - Non-Designated Hedges (Details)	Jun. 30, 2020 USD ($) derivativeContract	Dec. 31, 2019 USD ($) derivativeContract
Interest rate swaps
Derivative [Line Items]
Notional amount	$ 100,000,000
Interest rate swaps \| Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	1,600,000,000	$ 1,600,000,000
Foreign exchange contracts \| Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	0	0
Risk participation agreements \| Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	$ 58,100,000	$ 58,800,000
Number of contracts \| derivativeContract	7	7
Other Contract \| Not Designated as Hedging Instrument
Derivative [Line Items]
Notional amount	$ 30,400,000	$ 20,500,000
Number of contracts \| derivativeContract	5	4

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

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