Loans and Allowance for Credit Losses Narrative (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans with principal balances approximately in percentage	81.00%		83.00%
Unpaid principal balance, with no related allowance	$ 61,247		$ 68,595
Excluded from TDRs	3,500,000	$ 3,900,000
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum balance of loans evaluated individually for impairment	1,000		$ 1,000
Impaired loans balances, real estate as collateral	$ 1,000

Financing Receivable, Troubled Debt Restructuring, Postmodification, Excluded

No definition available.

Name:	fult_FinancingReceivableTroubledDebtRestructuringPostmodificationExcluded
Namespace Prefix:	fult_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the maximum balance of impaired loans that are pooled and evaluated collectively for impairment, rather than individually evaluated for impairment.

+ References

No definition available.

+ Details

Name:	fult_ImpairedLoanBalancesAllocatedReserves
Namespace Prefix:	fult_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the minimum principal balance threshold for disclosing impaired loans primarily secured by real estate that were measured at estimated fair value using certified third party appraisals updated in the previous 12 months.

+ References

No definition available.

+ Details

Name:	fult_ImpairedLoansBalancesRealEstateAsCollateral
Namespace Prefix:	fult_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of impaired loans primarily collateralized by real estate with principal balances greater than $1 million that were measured at estimated fair value using certified third party appraisals that had been updated in the previous 12 months.

+ References

No definition available.

+ Details

Name:	fult_ImpairedLoansWithPrincipalBalancesApproximatelyInPercentage
Namespace Prefix:	fult_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

No definition available.

+ Details

Name:	us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: