Borrowings - Narrative (Details)		6 Months Ended
Jul. 11, 2016 USD ($)	Jun. 30, 2020 USD ($) trust_subsidiary
Debt Instrument [Line Items]
Number of trust subsidiaries \| trust_subsidiary		9
Payment of interest on trust preferred securities		$ 0
Senior Notes \| Senior Notes Maturing July 2021
Debt Instrument [Line Items]
Debt instrument face amount	$ 250,000,000
Debt instrument redemption rate	100.00%
Senior Notes \| Senior Notes Maturing July 2021 \| Treasury Rate
Debt Instrument [Line Items]
Variable rate on interest rate	0.50%

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- Definition

Payment of Interest on Trust Preferred Securities

+ References

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
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