Commitments and Contingencies (Details 1) - Homebuilding [Member] - USD ($) $ in Millions	6 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Rollforward of reserves for legal claims
Reserves for legal claims, beginning of period	$ 451.0	$ 456.9
Increase in reserves	0.5	20.8
Payments	(25.3)	(28.3)
Reserves for legal claims, end of period	$ 426.2	$ 449.4

Amount of loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of payments made reducing loss contingency liability.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualCarryingValuePayments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in loss contingency liability.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=dhi_HomebuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: