Name:	us-gaap_ClassOfStockLineItems
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Data Type:	xbrli:stringItemType
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Period Type:	duration

The percentage rate used to calculate dividend payments on preferred stock.

No definition available.

Name:	us-gaap_PreferredStockDividendRatePercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

Name:	us-gaap_PreferredStockSharesOutstanding
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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Cash received on stock transaction after deduction of issuance costs.

No definition available.

Name:	us-gaap_SaleOfStockConsiderationReceivedOnTransaction
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

No definition available.

Name:	us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
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Data Type:	xbrli:sharesItemType
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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

No definition available.

Name:	us-gaap_SaleOfStockPricePerShare
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Data Type:	num:perShareItemType
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Period Type:	instant

Number of shares of stock issued during the period pursuant to acquisitions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_StockIssuedDuringPeriodSharesAcquisitions
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Data Type:	xbrli:sharesItemType
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Period Type:	duration

Name:	us-gaap_StatementClassOfStockAxis=htlf_SeriesDSeniorNoncumulativePerpetualConvertibleStockMember
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Data Type:	na
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Period Type:

Name:	us-gaap_StatementClassOfStockAxis=htlf_SeriesBSeniorNoncumulativePerpetualConvertibleStockMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=htlf_CICBancsharesInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_SubsidiarySaleOfStockAxis=htlf_PublicStockOfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
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