Fair Value Measurements Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Securities valued by the pricing service	80.00%	80.00%
Researched securities to reconcile the difference	5.00%	5.00%
Available for sale, at estimated fair value	$ 2,008,816	$ 2,008,816
Significant input, assumed market return to liquidity (years)	5 years
Other real estate owned (OREO)	$ 10,684	$ 10,684	$ 9,823
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Weighted average annual constant prepayment rate		8.80%
Weighted average discount rate		9.00%
Single-issuer Trust Preferred Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	19,596	$ 19,596	30,703
Pooled Trust Preferred Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	875	875	707
Fair Value, Measurements, Recurring [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	2,008,816	2,008,816
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	0	0
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	1,902,333	1,902,333
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	106,483	106,483
Fair Value, Measurements, Recurring [Member] \| Financial Institutions Subordinated Debt [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	67,900	67,900	61,900
Fair Value, Measurements, Recurring [Member] \| Single-issuer Trust Preferred Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	19,600	19,600	30,700
Fair Value, Measurements, Recurring [Member] \| Single-issuer Trust Preferred Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	17,000	17,000	27,700
Fair Value, Measurements, Recurring [Member] \| Single-issuer Trust Preferred Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	2,500	2,500	3,100
Fair Value, Measurements, Recurring [Member] \| Pooled Trust Preferred Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	875	875	707
Fair Value, Measurements, Recurring [Member] \| Other Corporate Debt [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Available for sale, at estimated fair value	4,000	4,000	4,000
Fair Value, Measurements, Recurring [Member] \| Trust for Benefit of Employees [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other financial liabilities	20,000	20,000	19,000
Fair Value, Measurements, Recurring [Member] \| Foreign Exchange Contract [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other financial liabilities	471	471	374
Foreign Exchange Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other financial assets	529	529	460
Forward Commitments [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other financial assets	1,400	1,400	1,100
Other financial liabilities	77	77	272
Interest Rate Swap [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other financial assets	65,700	65,700	43,400
Other financial liabilities	$ 75,000	$ 75,000	$ 38,700

Differences by security in excess of of threhold are researched to reconcile the difference.

No definition available.

Name:	fult_FairValueEquitySecuritiesFairValuePriceDifferenceThresholdPercent
Namespace Prefix:	fult_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of values provided by alternative third party source(s) undergoing additional research.

+ References

No definition available.

+ Details

Name:	fult_FairValueEquitySecuritiesValueTestCoveragePercent
Namespace Prefix:	fult_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Item represents the book value and estimated fair values of financial instruments catagorized within the other liabilities line item on the consolidated balance sheet.

+ References

No definition available.

+ Details

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

- Definition

Item represents the book value and estimated fair values of financial instruments catagorized within the other liabilities line item on the consolidated balance sheet.

+ References

No definition available.

+ Details

Name:	fult_OtherFinancialLiabilities
Namespace Prefix:	fult_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Significant Input, Assumed Market Return to Liquidity, Years

+ References

No definition available.

+ Details

Name:	fult_SignificantInputAssumedMarketReturnToLiquidityYears
Namespace Prefix:	fult_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

+ Details

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

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

- Definition

Carrying amount as of the balance sheet date of other real estate and foreclosed assets. Other real estate may include real estate investments, real estate loans that qualify as investments in real estate, and premises that are no longer used in operations may also be included in real estate owned. Foreclosed assets include all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122596-111746

+ Details

Name:	us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValueDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

+ References

+ Details

Name:	us-gaap_ServicingAssetsAndServicingLiabilitiesAtFairValueAssumptionsUsedToEstimateFairValuePrepaymentSpeed
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=fult_SingleIssuerTrustPreferredSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=fult_PooledTrustPreferredSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=fult_FinancialInstitutionsSubordinatedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=fult_OtherCorporateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_TrustForBenefitOfEmployeesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_ForwardContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: