Name:	hdb_TradingSecuritiesGrossUnrealizedGains
Namespace Prefix:	hdb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in trading securities impacting investments.

No definition available.

Name:	hdb_TradingSecuritiesGrossUnrealizedLosses
Namespace Prefix:	hdb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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.

No definition available.

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

Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Name:	us-gaap_TradingSecurities
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Cost of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

No definition available.

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

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

Name:	us-gaap_InvestmentTypeAxis=hdb_GovernmentOfIndiaSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InvestmentTypeAxis=hdb_SecuritiesOtherCorporateFinancialInstitutionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: